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Aviel-Ronen S, Rubinek T, Zadok O, Vituri A, Avivi C, Wolf I, Barshack I. Klotho expression in cervical cancer: differential expression in adenocarcinoma and squamous cell carcinoma. J Clin Pathol 2015. [PMID: 26209729 DOI: 10.1136/jclinpath-2015-202929] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS Klotho is a trans-membrane protein that serves as a tumour suppressor in a wide array of malignancies. Recent data suggest it as an epigenetically silenced tumour suppressor in cervical cancer. Yet, the expression pattern of klotho in cervical cancer has not been determined. We aimed to study the expression of klotho in squamous cell carcinomas (SQCC) and adenocarcinoma (ADC) of the cervix. METHODS Klotho expression was analysed by immunohistochemistry in 44 SQCC samples, 38 ADC samples and the adjacent normal tissue. For each sample, percentage of positive stained cells, staining intensity and a combined staining score were recorded. Staining was validated by measuring klotho mRNA levels, using quantitative RT-PCR, in 18 of the samples. RESULTS Klotho expression was high in all endocervical and exocervical normal tissues adjacent to tumour. No expression of klotho was noted in 7 out of 38 (18.4%) ADC samples and in 2 out of 44 (4.5%) SQCC samples. Staining intensity, number of positively stained cells and combined intensity score were all lower in tumours compared with normal adjacent tissues in ADC and SQCC. Klotho mRNA levels highly correlated with immunohistochemical (IHC) staining (p=0.008). CONCLUSIONS We found reduced klotho expression in cervical carcinoma, especially in ADC, compared with normal adjacent tissue. Our results support the role of klotho as a potential tumour suppressor in cervical cancer. Further studies are required in order to establish the therapeutic role of klotho in cervical carcinoma and identify patients who may benefit from it.
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Affiliation(s)
- Sarit Aviel-Ronen
- Department of Pathology, Sheba Medical Center, Tel Hashomer, Israel Talpiot Medical Leadership Program, Sheba Medical Center, Tel Hashomer, Israel
| | - Tami Rubinek
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv-Yafo, Israel
| | - Oranit Zadok
- Department of Pathology, Sheba Medical Center, Tel Hashomer, Israel
| | - Aya Vituri
- Department of Statistics and Operations Research, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Camila Avivi
- Department of Pathology, Sheba Medical Center, Tel Hashomer, Israel
| | - Ido Wolf
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv-Yafo, Israel Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
| | - Iris Barshack
- Department of Pathology, Sheba Medical Center, Tel Hashomer, Israel Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
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252
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Olauson H, Vervloet MG, Cozzolino M, Massy ZA, Ureña Torres P, Larsson TE. New insights into the FGF23-Klotho axis. Semin Nephrol 2015; 34:586-97. [PMID: 25498378 DOI: 10.1016/j.semnephrol.2014.09.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Abnormal mineral metabolism is a hallmark in patients with advanced chronic kidney disease (CKD). Hyperphosphatemia, and the homeostatic mechanisms controlling phosphate metabolism, have received particular attention over the past decade. The phosphate-regulating hormone fibroblast growth factor-23 (FGF23) was discovered through studies of rare hypophosphatemic disorders, whereas Klotho, which subsequently turned out to be a co-receptor for FGF23, was identified in a mouse model showing hyperphosphatemia and multiple aging-like traits. The FGF23-Klotho endocrine axis is a pivotal regulator of mineral metabolism. In CKD, early onset of Klotho deficiency contributes to renal FGF23 resistance and a maladaptive increase in circulating FGF23. FGF23 is an early biomarker of renal injury and increased FGF23 predicts adverse clinical outcomes, in particular cardiovascular disease. A paradigm of FGF23 excess and Klotho deficiency is proposed, in which FGF23 preferentially stimulates left ventricular hypertrophy, and loss of Klotho augments fibrosis, endothelial dysfunction, and vascular calcification. The clinical benefit of FGF23 and Klotho measurements remain uncertain, nevertheless, the FGF23-Klotho axis is a solid candidate for a novel diagnostic and therapeutic target in CKD.
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Affiliation(s)
- Hannes Olauson
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Marc G Vervloet
- Department of Nephrology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - Mario Cozzolino
- Department of Health Sciences, University of Milan, Renal Division, San Paolo Hospital, Milan, Italy
| | - Ziad A Massy
- Inserm U-1088, Université de Picardie Jules Verne (UPJV), Amiens, France; Division of Nephrology, Ambroise Paré Hospital, Paris-Ile-de-France-Ouest University (Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)), Paris-Boulogne Billancourt, France
| | - Pablo Ureña Torres
- Service of Nephrology and Dialysis, Clinique du Landy and Department of Renal Physiology, Necker Hospital, University of Paris Descartes, Paris, France
| | - Tobias E Larsson
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; Department of Nephrology, Karolinska University Hospital, Stockholm, Sweden.
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253
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Wolf I, Stein D, Shahmoon S, Ziv SI, Hemi R, Kanety H, Rubinek T, Modan-Moses D. Alteration in serum klotho levels in anorexia nervosa patients. Clin Nutr 2015; 35:958-62. [PMID: 26243062 DOI: 10.1016/j.clnu.2015.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 06/21/2015] [Accepted: 07/13/2015] [Indexed: 12/18/2022]
Abstract
BACKGROUND & AIMS Klotho is a trans-membrane protein which can be shed to act as a hormone; its blood levels may be regulated by the GH/IGF-1 axis. Klotho deficient mice exhibit short lifespan and characteristics of aging and malnutrition, including decreased fat and muscle mass, osteopenia, and impaired fertility. As anorexia nervosa (AN) is characterized by malnutrition and GH resistance, we hypothesized klotho levels would be altered in AN, and aimed to assess klotho levels in undernourished AN patients and changes in klotho following weight rehabilitation. PARTICIPANTS AND METHODS 19 adolescent female AN inpatients (aged 16.1 ± 1.8 years) admitted to an inpatient service for eating disorders in a tertiary center were recruited. Blood samples were obtained on admission and after weight restoration (interval 4.0 ± 2.3 months) and analyzed for klotho, IGF-1, calcium, phosphorus, and alkaline phosphatase. RESULTS Klotho levels on admission were lower than expected for age, and correlated with lumbar spine BMD Z-score (r = -0.81, p < 0.001) and alkaline phosphatase levels (r = 0.66, p = 0.003) but not with age, height-SDS, weight-SDS, BMI-SDS, or serum calcium, phosphorus and IGF-1 levels. Both IGF-1 and klotho levels increased significantly during hospitalization (IGF-1: 44 ± 17 nmol/l to 53 ± 11 nmol/l, p = 0.008; klotho: 1061 ± 421 pg/ml to 1519 ± 781 pg/ml, p = 0.008). CONCLUSIONS Klotho levels are low in the acute stage of AN and increase with nutritional rehabilitation. Low klotho on admission may be secondary to low IGF-1 levels and may contribute to the clinical manifestations of AN. The role of klotho in the pathophysiology of AN and as a novel marker of disease severity should be further explored.
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Affiliation(s)
- Ido Wolf
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Daniel Stein
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Pediatric Psychosomatic Department, The Edmond and Lily Safra Children's Hospital, The Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel
| | - Shiri Shahmoon
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Shimrit Ilana Ziv
- Pediatric Psychosomatic Department, The Edmond and Lily Safra Children's Hospital, The Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel
| | - Rina Hemi
- Institute of Endocrinology, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Hannah Kanety
- Institute of Endocrinology, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Tami Rubinek
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Dalit Modan-Moses
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel.
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Abstract
COPD (chronic obstructive pulmonary disease) is associated with sustained inflammation, excessive injury, and accelerated lung aging. Human Klotho (KL) is an anti-aging protein that protects cells against inflammation and damage. In the present study, we quantified KL expression in the lungs of COPD patients and in an ozone-induced mouse model of COPD, and investigated the mechanisms that control KL expression and function in the airways. KL distribution and levels in human and mouse airways were measured by immunohistochemistry and Western blotting. The effect of CSE (cigarette smoke extract) on KL expression was detected in human bronchial epithelial cells. Moreover, the effect of KL on CSE-mediated inflammation and hydrogen peroxide-induced cellular injury/apoptosis was determined using siRNAs. KL expression was decreased in the lungs of smokers and further reduced in patients with COPD. Similarly, 6 weeks of exposure to ozone decreased KL levels in airway epithelial cells. CSE and TNFα (tumour necrosis factor α) decreased KL expression and release from airway epithelial cells, which was associated with enhanced pro-inflammatory cytokine expression. Moreover, KL depletion increased cell sensitivity to cigarette smoke-induced inflammation and oxidative stress-induced cell damage. These effects involved the NF-κB (nuclear factor κB), MAPK (mitogen-activated protein kinase) and Nrf2 (nuclear factor erythroid 2-related factor 2) pathways. Reduced KL expression in COPD airway epithelial cells was associated with increased oxidative stress, inflammation and apoptosis. These data provide new insights into the mechanisms associated with the accelerated lung aging in COPD development.
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255
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van Loon EPM, Pulskens WP, van der Hagen EAE, Lavrijsen M, Vervloet MG, van Goor H, Bindels RJM, Hoenderop JGJ. Shedding of klotho by ADAMs in the kidney. Am J Physiol Renal Physiol 2015; 309:F359-68. [PMID: 26155844 DOI: 10.1152/ajprenal.00240.2014] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/01/2015] [Indexed: 11/22/2022] Open
Abstract
The anti-aging gene klotho plays an important role in Ca(2+) and phosphate homeostasis. Membrane-bound klotho is an essential coreceptor for fibroblast growth factor-23 and can be cleaved by proteases, including a disintegrin and metalloproteinase (ADAM)10 and ADAM17. Cleavage of klotho occurs at a site directly above the plasma membrane (α-cut) or between the KL1 and KL2 domain (β-cut), resulting in soluble full-length klotho or KL1 and KL2 fragments, respectively. The aim of the present study was to gain insights into the mechanisms behind klotho cleavage processes in the kidney. Klotho shedding was demonstrated using a Madin-Darby canine kidney cell line stably expressing klotho and human embryonic kidney-293 cells transiently transfected with klotho. Here, we report klotho expression on both the basolateral and apical membrane, with a higher abundance of klotho at the apical membrane and in the apical media. mRNA expression of ADAM17 and klotho were enriched in mouse distal convoluted and connecting tubules. In vitro ADAM/matrix metalloproteinase inhibition by TNF484 resulted in a concentration-dependent inhibition of the α-cut, with a less specific effect on β-cut shedding. In vivo TNF484 treatment in wild-type mice did not change urinary klotho levels. However, ADAM/matrix metalloproteinase inhibition did increase renal and duodenal mRNA expression of phosphate transporters, whereas serum phosphate levels were significantly decreased. In conclusion, our data show that renal cells preferentially secrete klotho to the apical side and suggest that ADAMs are responsible for α-cut cleavage.
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Affiliation(s)
- Ellen P M van Loon
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Wilco P Pulskens
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Eline A E van der Hagen
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marla Lavrijsen
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marc G Vervloet
- Department of Nephrology, VU University Medical Center, Amsterdam, The Netherlands; and
| | - Harry van Goor
- Department of Pathology and Medical Biology, University Medical Center Groningen, Groningen, The Netherlands
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands;
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256
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Hruska KA, Seifert M, Sugatani T. Pathophysiology of the chronic kidney disease-mineral bone disorder. Curr Opin Nephrol Hypertens 2015; 24:303-9. [PMID: 26050115 PMCID: PMC4699443 DOI: 10.1097/mnh.0000000000000132] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW The causes of excess cardiovascular mortality associated with chronic kidney disease (CKD) have been attributed in part to the CKD-mineral bone disorder syndrome (CKD-MBD), wherein, novel cardiovascular risk factors have been identified. The causes of the CKD-MBD are not well known and they will be discussed in this review RECENT FINDINGS The discovery of WNT (portmanteau of wingless and int) inhibitors, especially Dickkopf 1, produced during renal repair and participating in the pathogenesis of the vascular and skeletal components of the CKD-MBD implied that additional pathogenic factors are critical, leading to the finding that activin A is a second renal repair factor circulating in increased levels during CKD. Activin A derives from peritubular myofibroblasts of diseased kidneys, where it stimulates fibrosis, and decreases tubular klotho expression. The type 2 activin A receptor, ActRIIA, is decreased by CKD in atherosclerotic aortas, specifically in vascular smooth muscle cells (VSMC). Inhibition of activin signaling by a ligand trap inhibited CKD induced VSMC dedifferentiation, osteogenic transition and atherosclerotic calcification. Inhibition of activin signaling in the kidney decreased renal fibrosis and proteinuria. SUMMARY These studies demonstrate that circulating renal repair factors are causal for the CKD-MBD and CKD associated cardiovascular disease, and identify ActRIIA signaling as a therapeutic target in CKD that links progression of renal disease and vascular disease.
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Affiliation(s)
- Keith A. Hruska
- Department of Pediatrics, Nephrology, Washington University Saint Louis, MO
- Departments of Medicine and Cell Biology Washington University Saint Louis, MO
| | - Michael Seifert
- Department of Pediatrics, Nephrology, Washington University Saint Louis, MO
- Department of Pediatrics, Nephrology, Southern Illinois University, Springfield IL
| | - Toshifumi Sugatani
- Department of Pediatrics, Nephrology, Washington University Saint Louis, MO
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257
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Seo MY, Yang J, Lee JY, Kim K, Kim SC, Chang H, Won NH, Kim MG, Jo SK, Cho W, Kim HK. Renal Klotho expression in patients with acute kidney injury is associated with the severity of the injury. Korean J Intern Med 2015; 30:489-95. [PMID: 26161015 PMCID: PMC4497336 DOI: 10.3904/kjim.2015.30.4.489] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 05/16/2014] [Accepted: 08/18/2014] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND/AIMS The potential physiologic roles of Klotho in acute kidney injury (AKI) have recently been demonstrated in animal models. However, to date, there have been no human studies investigating the expression of renal Klotho in AKI. METHODS We retrospectively collected biopsy specimens and clinical data of AKI patients between January 2001 and December 2012. Klotho expression was determined by immunohistochemical staining, and the clinical-pathological correlation was examined. RESULTS Among the 34 patients diagnosed with acute tubular necrosis or acute tubulointerstitial nephritis, 21 patients without chronic histological lesions were included. The mean age was 37.3 ± 18.5 years and the mean peak creatinine level was 8.2 ± 5.5 mg/dL. In total, 10 patients (47.6%) received temporary renal replacement therapy (RRT); however, 17 patients (81%) showed functional recovery with creatinine levels of < 1.3 mg/dL after 1 month. The intensity of Klotho expression was scored as a percentage of Klotho-positive area. The renal Klotho score showed a significant negative correlation with the initial or peak creatinine level. When the patients were divided into three groups according to the Klotho score (low, middle, high), the low group had a significantly higher peak creatinine level and a more frequent requirement for RRT. However, the Klotho score was not a significant predictor of renal recovery. CONCLUSIONS The results demonstrated that renal Klotho expression in humans decreased significantly according to the severity of AKI, regardless of the etiology, and that low expression was associated with a poor short-term outcome.
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Affiliation(s)
- Min Young Seo
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
| | - Jihyun Yang
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
| | - Jun Yong Lee
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
| | - Kitae Kim
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
| | - Sun Chul Kim
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
| | - Hyojeong Chang
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
| | - Nam Hee Won
- Department of Pathology, Korea University Anam Hospital, Seoul, Korea
| | - Myung-Gyu Kim
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
| | - Sang-Kyung Jo
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
| | - Wonyong Cho
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
| | - Hyoung Kyu Kim
- Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea
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258
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Qian M, Shen X, Wang H. The Distinct Role of ADAM17 in APP Proteolysis and Microglial Activation Related to Alzheimer's Disease. Cell Mol Neurobiol 2015; 36:471-82. [PMID: 26119306 DOI: 10.1007/s10571-015-0232-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/23/2015] [Indexed: 01/03/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease with the symptom of cognitive impairment. The deposition of amyloid β (Aβ) peptide is believed to be the primary cause to neuronal dystrophy and eventually dementia. Aβ is the proteolytic product from its precursor amyloid precursor protein (APP) by β- and γ- secretase. An optional cleavage by α-secretase happens inside the Aβ domain. ADAM17 is supposed to be the regulated α-secretase of APP. Enhanced activity of ADAM17 leads to the increasing secretion of neuroprotective soluble APP α fragment and reduction of Aβ generation, which may be benefit to the disease. ADAM17 is then considered the potential therapeutic target for AD. Microglia activation and neuroinflammation is another important event in AD pathogenesis. Interestingly, ADAM17 also participates in the cleavage of many other membrane-bound proteins, especially some inflammatory factors related to microglia activation. The facilitating role of ADAM17 in inflammation and further neuronal damage has also been illustrated. In results, the activation of ADAM17 as the solution to AD may be a tricky task. The comprehensive consideration and evaluation has to be carried out carefully before the final treatment. In the present review, the distinct role of ADAM17 in AD-related APP shedding and neuroinflammatory microglial activation will be carefully discussed.
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Affiliation(s)
- Meng Qian
- Key Lab of Inflammation and Immunoregulation, School of Medicine, Hangzhou Normal University, Xuelin Street 16, Hangzhou, 310036, China
| | - Xiaoqiang Shen
- Key Lab of Inflammation and Immunoregulation, School of Medicine, Hangzhou Normal University, Xuelin Street 16, Hangzhou, 310036, China
| | - Huanhuan Wang
- Key Lab of Inflammation and Immunoregulation, School of Medicine, Hangzhou Normal University, Xuelin Street 16, Hangzhou, 310036, China.
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259
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Mencke R, Harms G, Mirković K, Struik J, Van Ark J, Van Loon E, Verkaik M, De Borst MH, Zeebregts CJ, Hoenderop JG, Vervloet MG, Hillebrands JL. Membrane-bound Klotho is not expressed endogenously in healthy or uraemic human vascular tissue. Cardiovasc Res 2015; 108:220-31. [PMID: 26116633 DOI: 10.1093/cvr/cvv187] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 06/23/2015] [Indexed: 01/29/2023] Open
Abstract
AIMS Cardiovascular disease (CVD) is the leading cause of death in patients with chronic kidney disease (CKD), a disease state that is strongly associated with loss of renal and systemic (alpha-)Klotho. Reversely, murine Klotho deficiency causes marked medial calcification. It is therefore thought that Klotho conveys a vasculoprotective effect. Klotho expression in the vessel wall, however, is disputed. METHODS AND RESULTS We assessed Klotho expression in healthy human renal donor arteries (n = 9), CKD (renal graft recipient) arteries (n = 10), carotid endarterectomy specimens (n = 8), other elastic arteries (three groups of n = 3), and cultured human aortic smooth muscle cells (HASMCs) (three primary cell lines), using immunohistochemistry (IHC), immunofluorescence, quantitative reverse transcriptase-polymerase chain reaction, and western blotting (WB). We have extensively validated anti-Klotho antibody KM2076 by comparing staining patterns with other anti-Klotho antibodies (SC-22220, SC-22218, and AF1819), competition assays with recombinant Klotho, IHC on Klotho-deficient kl/kl mouse kidney, and WB with recombinant Klotho. Using KM2076, we could not detect full-length Klotho in vascular tissues or HASMCs. On the mRNA level, using primers against all four exon junctions, klotho expression could not be detected either. Fibroblast growth factor 23 (FGF23) injections in mice induced FGF23 signalling in kidneys but not in the aorta, indicating the absence of Klotho-dependent FGF23 signalling in the aorta. CONCLUSION Using several independent and validated methods, we conclude that full-length, membrane-bound Klotho is not expressed in healthy or uraemic human vascular tissue.
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Affiliation(s)
- Rik Mencke
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen, HPC EA10, PO Box 30.001, Groningen 9700 RB, The Netherlands
| | - Geert Harms
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen, HPC EA10, PO Box 30.001, Groningen 9700 RB, The Netherlands
| | - Katarina Mirković
- Department of Internal Medicine (Division of Nephrology), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Joyce Struik
- Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands
| | - Joris Van Ark
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen, HPC EA10, PO Box 30.001, Groningen 9700 RB, The Netherlands
| | - Ellen Van Loon
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Melissa Verkaik
- Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands
| | - Martin H De Borst
- Department of Internal Medicine (Division of Nephrology), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Clark J Zeebregts
- Department of Surgery (Division of Vascular Surgery), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Joost G Hoenderop
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marc G Vervloet
- Department of Nephrology, VU University Medical Center, Amsterdam, The Netherlands
| | - Jan-Luuk Hillebrands
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen, HPC EA10, PO Box 30.001, Groningen 9700 RB, The Netherlands
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Ligumsky H, Rubinek T, Merenbakh-Lamin K, Yeheskel A, Sertchook R, Shahmoon S, Aviel-Ronen S, Wolf I. Tumor Suppressor Activity of Klotho in Breast Cancer Is Revealed by Structure–Function Analysis. Mol Cancer Res 2015; 13:1398-407. [DOI: 10.1158/1541-7786.mcr-15-0141] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/10/2015] [Indexed: 11/16/2022]
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261
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The Anti-Aging Protein Klotho Enhances Remyelination Following Cuprizone-Induced Demyelination. J Mol Neurosci 2015; 57:185-96. [DOI: 10.1007/s12031-015-0598-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/02/2015] [Indexed: 01/23/2023]
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Prather AA, Epel ES, Arenander J, Broestl L, Garay BI, Wang D, Dubal DB. Longevity factor klotho and chronic psychological stress. Transl Psychiatry 2015; 5:e585. [PMID: 26080320 PMCID: PMC4490291 DOI: 10.1038/tp.2015.81] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 05/07/2015] [Indexed: 12/31/2022] Open
Abstract
Chronic psychological stress is associated with accelerated aging and premature morbidity and mortality; however, the biology linking chronic psychological stress and its maladaptive effects remains largely unknown. Klotho is a pleiotropic hormone that regulates the aging process and promotes better brain and body health. Whether klotho is linked to psychosocial stress or its negative impact in humans has not been investigated. To address this gap, we recruited 178 healthy women who were either chronically high-stress maternal caregivers for a child with autism spectrum disorder (n = 90) or low-stress control mothers of a typically developing child (n = 88). We found that women under high chronic stress displayed significantly lower levels of the longevity hormone klotho compared with low-stress controls (t(176) = 2.92, P = 0.004; d = 0.44), and the decrease among those under high stress was age-dependent. In addition, high-stress caregivers who reported more depressive symptoms displayed even lower klotho levels compared with low-stress participants. These findings provide the first evidence that klotho levels are sensitive to psychosocial stressors and raise the possibility that klotho may serve as a novel biological link connecting stress, depression and risk for accelerated disease development. Furthermore, these findings have important implications for understanding the plasticity of the aging process and may represent a therapeutic target for mitigating the deleterious effects of chronic psychological stress on health and well-being.
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Affiliation(s)
- A A Prather
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA,Department of Psychiatry, University of California, San Francisco, 3333 California Street, Suite 465, San Francisco, CA 94118, USA E-mail:
| | - E S Epel
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA
| | - J Arenander
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA
| | - L Broestl
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - B I Garay
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - D Wang
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - D B Dubal
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA,Department of Neurology, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158, USA. E-mail:
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Life extension factor klotho prevents mortality and enhances cognition in hAPP transgenic mice. J Neurosci 2015; 35:2358-71. [PMID: 25673831 DOI: 10.1523/jneurosci.5791-12.2015] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Aging is the principal demographic risk factor for Alzheimer disease (AD), the most common neurodegenerative disorder. Klotho is a key modulator of the aging process and, when overexpressed, extends mammalian lifespan, increases synaptic plasticity, and enhances cognition. Whether klotho can counteract deficits related to neurodegenerative diseases, such as AD, is unknown. Here we show that elevating klotho expression decreases premature mortality and network dysfunction in human amyloid precursor protein (hAPP) transgenic mice, which simulate key aspects of AD. Increasing klotho levels prevented depletion of NMDA receptor (NMDAR) subunits in the hippocampus and enhanced spatial learning and memory in hAPP mice. Klotho elevation in hAPP mice increased the abundance of the GluN2B subunit of NMDAR in postsynaptic densities and NMDAR-dependent long-term potentiation, which is critical for learning and memory. Thus, increasing wild-type klotho levels or activities improves synaptic and cognitive functions, and may be of therapeutic benefit in AD and other cognitive disorders.
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264
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Lin Y, Sun Z. In vivo pancreatic β-cell-specific expression of antiaging gene Klotho: a novel approach for preserving β-cells in type 2 diabetes. Diabetes 2015; 64:1444-58. [PMID: 25377875 PMCID: PMC4375073 DOI: 10.2337/db14-0632] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein expression of an antiaging gene, Klotho, was depleted in pancreatic islets in patients with type 2 diabetes mellitus (T2DM) and in db/db mice, an animal model of T2DM. The objective of this study was to investigate whether in vivo expression of Klotho would preserve pancreatic β-cell function in db/db mice. We report for the first time that β-cell-specific expression of Klotho attenuated the development of diabetes in db/db mice. β-Cell-specific expression of Klotho decreased hyperglycemia and enhanced glucose tolerance. The beneficial effects of Klotho were associated with significant improvements in T2DM-induced decreases in number of β-cells, insulin storage levels in pancreatic islets, and glucose-stimulated insulin secretion from pancreatic islets, which led to increased blood insulin levels in diabetic mice. In addition, β-cell-specific expression of Klotho decreased intracellular superoxide levels, oxidative damage, apoptosis, and DNAJC3 (a marker for endoplasmic reticulum stress) in pancreatic islets. Furthermore, β-cell-specific expression of Klotho increased expression levels of Pdx-1 (insulin transcription factor), PCNA (a marker of cell proliferation), and LC3 (a marker of autophagy) in pancreatic islets in db/db mice. These results reveal that β-cell-specific expression of Klotho improves β-cell function and attenuates the development of T2DM. Therefore, in vivo expression of Klotho may offer a novel strategy for protecting β-cells in T2DM.
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Affiliation(s)
- Yi Lin
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Zhongjie Sun
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK
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265
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Abstract
The discovery of the Klotho (KL) gene, which was originally identified as a putative aging-suppressor gene, has generated tremendous interest and has advanced understanding of the aging process. In mice, the overexpression of the KL gene extends the life span, whereas mutations to the KL gene shorten the life span. The human KL gene encodes the α-Klotho protein, which is a multifunctional protein that regulates the metabolism of phosphate, calcium, and vitamin D. α-Klotho also may function as a hormone, although the α-Klotho receptor(s) has not been found. Point mutations of the KL gene in humans are associated with hypertension and kidney disease, which suggests that α-Klotho may be essential to the maintenance of normal renal function. Three α-Klotho protein types with potentially different functions have been identified: a full-length transmembrane α-Klotho, a truncated soluble α-Klotho, and a secreted α-Klotho. Recent evidence suggests that α-Klotho suppresses the insulin and Wnt signaling pathways, inhibits oxidative stress, and regulates phosphatase and calcium absorption. In this review, we provide an update on recent advances in the understanding of the molecular, genetic, biochemical, and physiological properties of the KL gene. Specifically, this review focuses on the structure of the KL gene and the factors that regulate KL gene transcription, the key sites in the regulation of α-Klotho enzyme activity, the α-Klotho signaling pathways, and the molecular mechanisms that underlie α-Klotho function. This current understanding of the molecular biology of the α-Klotho protein may offer new insights into its function and role in aging.
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Affiliation(s)
- Yuechi Xu
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
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266
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Kim JH, Hwang KH, Park KS, Kong ID, Cha SK. Biological Role of Anti-aging Protein Klotho. J Lifestyle Med 2015; 5:1-6. [PMID: 26528423 PMCID: PMC4608225 DOI: 10.15280/jlm.2015.5.1.1] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 02/16/2015] [Indexed: 12/15/2022] Open
Abstract
Klotho-deficient mice have accelerated aging phenotypes, whereas overexpression of Klotho in mice extends lifespan. Klotho is an anti-aging single-pass membrane protein predominantly produced in the kidney, with shedding of the amino-terminal extracellular domain into the systemic circulation. Circulating levels of soluble Klotho decrease with age, and the klotho gene is associated with increased risk of age-related diseases. The three forms of Klotho protein have distinct functions. Membrane Klotho forms a complex with fibroblast growth factor (FGF) receptors, functions as an obligatory co-receptor for FGF23, which is involved in aging and the development of chronic diseases via regulation of Pi and vitamin D metabolism. Secreted Klotho functions as a humoral factor with pleiotropic activities including regulation of oxidative stress, growth factor signaling, and ion homeostasis. Secreted Klotho is also involved in organ protection. The intracellular form of Klotho suppresses inflammation-mediated cellular senescence and mineral metabolism. Herein we provide a brief overview of the structure and function and recent research about Klotho.
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Affiliation(s)
- Ji-Hee Kim
- Departments of Physiology and Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Kyu-Hee Hwang
- Departments of Physiology and Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Kyu-Sang Park
- Departments of Physiology and Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Korea ; Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - In Deok Kong
- Departments of Physiology and Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Korea ; Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Seung-Kuy Cha
- Departments of Physiology and Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Korea ; Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea ; Nuclear Receptor Research Consortium, Yonsei University Wonju College of Medicine, Wonju, Korea
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267
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Lojkin I, Rubinek T, Orsulic S, Schwarzmann O, Karlan BY, Bose S, Wolf I. Reduced expression and growth inhibitory activity of the aging suppressor klotho in epithelial ovarian cancer. Cancer Lett 2015; 362:149-57. [PMID: 25827069 DOI: 10.1016/j.canlet.2015.03.035] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/16/2015] [Accepted: 03/17/2015] [Indexed: 12/22/2022]
Abstract
Klotho is an anti-aging transmembrane protein, which can be shed and function as a hormone. Accumulating data indicate klotho as a tumor suppressor in a wide array of malignancies, and we identified klotho as an inhibitor of the insulin-like growth factor (IGF-1) pathway in cancer cells. As this pathway is significant in the development of epithelial ovarian cancer (EOC) we studied klotho expression and activity in this tumor. Klotho mRNA levels were reduced in 16 of 19 EOC cell lines and immunohistochemistry analysis revealed high expression in normal ovaries, and reduced expression in 100 of 241 high grade papillary-serous adenocarcinoma of the ovaries, fallopian tubes and peritoneum. Reduced expression was associated with wild-type BRCA status. Klotho reduced EOC cell viability, enhanced cisplatin sensitivity, and reduced expression of mesenchymal markers. Finally, klotho inhibited IGF-1 pathway activation and inhibited transcriptional activity of the estrogen receptor. In conclusion, klotho is silenced in a substantial subset of the tumors and restoring its expression slows growth of EOC cells and inhibits major signaling pathways. As klotho is a hormone, treatment with klotho may serve as a novel treatment for EOC.
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Affiliation(s)
- Irina Lojkin
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tami Rubinek
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Sandra Orsulic
- Women's Cancer Program, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Omer Schwarzmann
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Beth Y Karlan
- Women's Cancer Program, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Shikha Bose
- Department of Pathology & Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Ido Wolf
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
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268
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Abstract
Phosphate is essential for growth and maintenance of the skeleton and for generating high-energy phosphate compounds. Evolutionary adaptation to high dietary phosphorous in humans and other terrestrial vertebrates involves regulated mechanisms assuring the efficient renal elimination of excess phosphate. These mechanisms prominently include PTH, FGF23, and Vitamin D, which directly and indirectly regulate phosphate transport. Disordered phosphate homeostasis is associated with pathologies ranging from kidney stones to kidney failure. Chronic kidney disease results in hyperphosphatemia, an elevated calcium×phosphate product with considerable morbidity and mortality, mostly associated with adverse cardiovascular events. This chapter highlights recent findings and insights regarding the hormonal regulation of renal phosphate transport along with imbalances of phosphate balance due to acquired or inherited diseases states.
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269
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Torregrosa I, Montoliu C, Urios A, Giménez-Garzó C, Tomás P, Solís MÁ, Ramos C, Juan I, Puchades MJ, Saez GT, Blasco ML, Miguel A. Klotho urinario determinado por ELISA como biomarcador precoz de fracaso renal agudo en pacientes sometidos a cirugía cardiaca o angiografía coronaria. Nefrologia 2015; 35:172-8. [DOI: 10.1016/j.nefro.2014.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 12/03/2014] [Indexed: 01/30/2023] Open
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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: 65] [Impact Index Per Article: 7.2] [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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271
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Wolf MTF, An SW, Nie M, Bal MS, Huang CL. Klotho up-regulates renal calcium channel transient receptor potential vanilloid 5 (TRPV5) by intra- and extracellular N-glycosylation-dependent mechanisms. J Biol Chem 2014; 289:35849-57. [PMID: 25378396 PMCID: PMC4276853 DOI: 10.1074/jbc.m114.616649] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 10/30/2014] [Indexed: 11/06/2022] Open
Abstract
The anti-aging protein Klotho is a type 1 membrane protein produced predominantly in the distal convoluted tubule. The ectodomain of Klotho is cleaved and secreted into the urine to regulate several ion channels and transporters. Secreted Klotho (sKL) up-regulates the TRPV5 calcium channel from the cell exterior by removing sialic acids from N-glycan of the channel and inhibiting its endocytosis. Because TRPV5 and Klotho coexpress in the distal convoluted tubule, we investigated whether Klotho regulates TRPV5 action from inside the cell. Whole-cell TRPV5-mediated channel activity was recorded in HEK cells coexpressing TRPV5 and sKL or membranous Klotho (mKL). Transfection of sKL, but not mKL, produced detectable Klotho protein in cell culture media. As for sKL, mKL increased TRPV5 current density. The role of sialidase activity of mKL acting inside is supported by findings that mutations of putative sialidase activity sites in sKL and mKL abrogated the regulation of TRPV5 but that the extracellular application of a sialidase inhibitor prevented the regulation of TRPV5 by sKL only. Mechanistically, coexpression with a dominant-negative dynamin II prevented the regulation of TRPV5 by sKL but not by mKL. In contrast, blocking forward trafficking by brefeldin A prevented the effect with mKL but not with sKL. Therefore, Klotho up-regulates TRPV5 from both the inside and outside of cells. The intracellular action of Klotho is likely due to enhanced forward trafficking of channel proteins, whereas the extracellular action is due to inhibition of endocytosis. Both effects involve putative Klotho sialidase activity. These effects of Klotho may play important roles regarding calcium reabsorption in the kidney.
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Affiliation(s)
| | - Sung-Wan An
- Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | | | | | - Chou-Long Huang
- Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
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272
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de Souza Pacheco APA, Goncalves M. Klotho: its various functions and association with sickle cell disease subphenotypes. Rev Bras Hematol Hemoter 2014; 36:430-6. [PMID: 25453654 PMCID: PMC4318548 DOI: 10.1016/j.bjhh.2014.07.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 07/21/2014] [Indexed: 12/20/2022] Open
Abstract
The Klotho protein, whose gene has predominant renal expression, acts in the control of serum phosphorus and 1,25-dihydroxyvitamin D3 and regulates the function of ion channels. It also participates in the mechanism of protection against oxidative stress and acts on the vascular endothelium by inducing the production of nitric oxide. Mutations that reflect defects in the Klotho gene expression may be implicated in the onset of osteonecrosis, priapism, and leg ulcers in patients with sickle cell disease, as a result of oxidative stress and endothelial impairment, important factors in the development and severity of this disease. Previous reports regarding the association of Klotho single nucleotide polymorphisms with sickle cell disease subphenotypes have found that these polymorphisms are important to identify genetic markers of risk in these individuals and allow early and more effective therapeutic intervention.
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Affiliation(s)
| | - Marilda Goncalves
- Fundação Oswaldo Cruz (FIOCRUZ), Salvador, BA, Brazil; Universidade Federal da Bahia (UFBA), Salvador, BA, Brazil.
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273
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Tan SJ, Smith ER, Hewitson TD, Holt SG, Toussaint ND. Diurnal variation and short-term pre-analytical stability of serum soluble α-klotho in healthy volunteers: a pilot study. Ann Clin Biochem 2014; 52:506-9. [PMID: 25416731 DOI: 10.1177/0004563214563415] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2014] [Indexed: 11/16/2022]
Abstract
AIM To investigate the diurnal variability and pre-analytical stability of soluble α-klotho in serum. BACKGROUND Recent evidence suggests that the cleaved extracellular domain of the α-klotho receptor, soluble α-klotho, affects phosphate homeostasis, ion channel regulation and antifibrotic/antioxidant pathways. However, soluble α-klotho measurements have yielded inconsistent results when related to renal function, markers of mineral metabolism and patient outcomes. Pre-analytical factors such as biological variation and analyte stability may affect the interpretation of soluble α-klotho results but are yet to be formally assessed. METHODS Clotted blood samples were collected from 10 healthy adult volunteers at three time-points during the day to assess diurnal change. Additional samples were collected and allowed to stand at room temperature for 30, 60 and 120 min, prior to centrifugation and analysis to evaluate analyte stability. Serum soluble α-klotho was measured using a validated commercial enzyme-linked immunosorbent assay. RESULTS Delayed processing of samples had no significant effect on serum soluble α-klotho concentrations over a 2-h period. Serum soluble α-klotho concentrations remained stable over morning, midday and afternoon time-points in this pilot study. CONCLUSION Serum soluble α-klotho demonstrates short-term pre-analytical stability and minimal diurnal variability in this pilot study. Larger studies are warranted to confirm these findings.
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Affiliation(s)
- Sven-Jean Tan
- Department of Nephrology, The Royal Melbourne Hospital (RMH), Parkville, Australia Department of Medicine (RMH), The University of Melbourne, Melbourne, Australia
| | - Edward R Smith
- Department of Nephrology, The Royal Melbourne Hospital (RMH), Parkville, Australia
| | - Tim D Hewitson
- Department of Nephrology, The Royal Melbourne Hospital (RMH), Parkville, Australia Department of Medicine (RMH), The University of Melbourne, Melbourne, Australia
| | - Stephen G Holt
- Department of Nephrology, The Royal Melbourne Hospital (RMH), Parkville, Australia Department of Medicine (RMH), The University of Melbourne, Melbourne, Australia
| | - Nigel D Toussaint
- Department of Nephrology, The Royal Melbourne Hospital (RMH), Parkville, Australia Department of Medicine (RMH), The University of Melbourne, Melbourne, Australia
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274
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Latifyan SB, Vanhaeverbeek M, Klastersky J. Tumour-associated osteomalacia and hypoglycaemia in a patient with prostate cancer: is Klotho involved? BMJ Case Rep 2014; 2014:bcr-2014-206590. [PMID: 25406200 DOI: 10.1136/bcr-2014-206590] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Tumour-associated osteomalacia is a paraneoplastic syndrome caused by renal phosphate wasting, leading to severe hypophosphataemia. Excess of circulating fibroblast growth factor 23 (FGF23) is the likely cause, acting via the FGF23/α-Klotho coreceptor, a critical regulator of phosphate metabolism. The other possible effects of that complex in humans are still under investigation. We present a case of an 84-year-old Belgian man, presenting prostate cancer with bone metastases. From June 2010 to March 2013, he presented three episodes of disease progression. From January 2012, the patient developed a progressively marked dorsal kyphosis with significant hypophosphataemia. The calculated TRP (tubular reabsorption of phosphate) was decreased and the FGF23 increased. Mid-March 2013, the patient died after a profound unconsciousness due to hypoglycaemia with hypothermia. We hypothesised that the two paraneoplastic manifestations of this patient (tumour-associated osteomalacia and refractory hypoglycaemia) were due to one cause chain with two main nodes-FGF23 and its coreceptor Klotho..
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Affiliation(s)
- Sofiya Bedo Latifyan
- Institut Jules Bordet, Brussels, Belgium Université Libre de Bruxelles, Brussels, Belgium
| | - Michel Vanhaeverbeek
- Université Libre de Bruxelles, Brussels, Belgium Centre Hospitalo-Universitaire de Charleroi, Charleroi, Belgium
| | - Jean Klastersky
- Institut Jules Bordet, Brussels, Belgium Université Libre de Bruxelles, Brussels, Belgium
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275
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Nitta K, Nagano N, Tsuchiya K. Fibroblast growth factor 23/klotho axis in chronic kidney disease. Nephron Clin Pract 2014; 128:1-10. [PMID: 25402964 DOI: 10.1159/000365787] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 06/26/2014] [Indexed: 12/27/2022] Open
Abstract
Fibroblast growth factor-23 (FGF23) is a bone-derived hormone that regulates phosphate and 1,25-hydroxyvitamin D [1,25(OH)2D] metabolism. FGF23 binds to FGF receptor 1 with its coreceptor Klotho and maintains serum phosphate levels within the normal range by increasing renal phosphate excretion. In addition, FGF23 reduces the synthesis and accelerates the degradation of 1,25(OH)2D to reduce intestinal phosphate absorption. Moreover, FGF23 acts at the parathyroid gland to decrease parathyroid hormone synthesis and secretion. In chronic kidney disease (CKD), serum FGF23 levels rise exponentially as renal function declines long before a significant increase in serum phosphate concentration occurs. Although there is room for argument, FGF23 and Klotho are recently reported contributors to vascular calcification. Finally, prospective observational studies have shown that serum FGF23 concentrations predict mortality not only among dialysis patients but among predialysis CKD patients. In addition to being a coreceptor for FGF23, Klotho circulates as an endocrine substance and exerts a multitude of effects. This review describes recent advances in research on the FGF23-Klotho axis in CKD. © 2014 S. Karger AG, Basel.
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Affiliation(s)
- Kosaku Nitta
- Kidney Center, Department of Medicine, Tokyo Women's Medical University, Tokyo, Japan
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276
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Hu MC, Shi M, Cho HJ, Adams-Huet B, Paek J, Hill K, Shelton J, Amaral AP, Faul C, Taniguchi M, Wolf M, Brand M, Takahashi M, Kuro-O M, Hill JA, Moe OW. Klotho and phosphate are modulators of pathologic uremic cardiac remodeling. J Am Soc Nephrol 2014; 26:1290-302. [PMID: 25326585 DOI: 10.1681/asn.2014050465] [Citation(s) in RCA: 208] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 08/21/2014] [Indexed: 12/14/2022] Open
Abstract
Cardiac dysfunction in CKD is characterized by aberrant cardiac remodeling with hypertrophy and fibrosis. CKD is a state of severe systemic Klotho deficiency, and restoration of Klotho attenuates vascular calcification associated with CKD. We examined the role of Klotho in cardiac remodeling in models of Klotho deficiency-genetic Klotho hypomorphism, high dietary phosphate intake, aging, and CKD. Klotho-deficient mice exhibited cardiac dysfunction and hypertrophy before 12 weeks of age followed by fibrosis. In wild-type mice, the induction of CKD led to severe cardiovascular changes not observed in control mice. Notably, non-CKD mice fed a high-phosphate diet had lower Klotho levels and greatly accelerated cardiac remodeling associated with normal aging compared with those on a normal diet. Chronic elevation of circulating Klotho because of global overexpression alleviated the cardiac remodeling induced by either high-phosphate diet or CKD. Regardless of the cause of Klotho deficiency, the extent of cardiac hypertrophy and fibrosis correlated tightly with plasma phosphate concentration and inversely with plasma Klotho concentration, even when adjusted for all other covariables. High-fibroblast growth factor-23 concentration positively correlated with cardiac remodeling in a Klotho-deficient state but not a Klotho-replete state. In vitro, Klotho inhibited TGF-β1-, angiotensin II-, or high phosphate-induced fibrosis and abolished TGF-β1- or angiotensin II-induced hypertrophy of cardiomyocytes. In conclusion, Klotho deficiency is a novel intermediate mediator of pathologic cardiac remodeling, and fibroblast growth factor-23 may contribute to cardiac remodeling in concert with Klotho deficiency in CKD, phosphotoxicity, and aging.
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Affiliation(s)
- Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Departments of Internal Medicine,
| | - Mingjun Shi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Han Jun Cho
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Beverley Adams-Huet
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Departments of Internal Medicine, Clinical Sciences
| | - Jean Paek
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Kathy Hill
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | | | - Ansel P Amaral
- Division of Nephrology and Hypertension, Department of Medicine and Department of Cell Biology and Anatomy, University of Miami Miller School of Medicine, Miami, Florida; and
| | - Christian Faul
- Division of Nephrology and Hypertension, Department of Medicine and Department of Cell Biology and Anatomy, University of Miami Miller School of Medicine, Miami, Florida; and
| | - Masatomo Taniguchi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Clinical Sciences
| | - Myles Wolf
- Division of Nephrology and Hypertension, Department of Medicine and
| | - Markus Brand
- Department of Internal Medicine D, University of Münster, Münster, Germany
| | - Masaya Takahashi
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Makoto Kuro-O
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Pathology
| | - Joseph A Hill
- Departments of Internal Medicine, Molecular Biology, and
| | - Orson W Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Departments of Internal Medicine, Physiology, and
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Barker SL, Pastor J, Carranza D, Quiñones H, Griffith C, Goetz R, Mohammadi M, Ye J, Zhang J, Hu MC, Kuro-o M, Moe OW, Sidhu SS. The demonstration of αKlotho deficiency in human chronic kidney disease with a novel synthetic antibody. Nephrol Dial Transplant 2014; 30:223-33. [PMID: 25324355 DOI: 10.1093/ndt/gfu291] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND αKlotho is the prototypic member of the Klotho family and is most highly expressed in the kidney. αKlotho has pleiotropic biologic effects, and in the kidney, its actions include regulation of ion transport, cytoprotection, anti-oxidation and anti-fibrosis. In rodent models of chronic kidney disease (CKD), αKlotho deficiency has been shown to be an early biomarker as well as a pathogenic factor. The database for αKlotho in human CKD remains controversial even after years of study. METHODS We used a synthetic antibody library to identify a high-affinity human antigen-binding fragment that recognizes human, rat and mouse αKlotho primarily in its native, rather than denatured, form. RESULTS Using an immunoprecipitation-immunoblot (IP-IB) assay, we measured both serum and urinary levels of full-length soluble αKlotho in humans and established that human CKD is associated with αKlotho deficiency in serum and urine. αKlotho levels were detectably lower in early CKD preceding disturbances in other parameters of mineral metabolism and progressively declined with CKD stages. We also found that exogenously added αKlotho is inherently unstable in the CKD milieu suggesting that decreased production may not be the sole reason for αKlotho deficiency. CONCLUSION Synthetic antibody libraries harbor tremendous potential for a variety of biomedical and clinical applications. Using such a reagent, we furnish data in support of αKlotho deficiency in human CKD, and we set the foundation for the development of diagnostic and therapeutic applications of anti-αKlotho antibodies.
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Affiliation(s)
- Sarah L Barker
- Banting and Best Department of Medical Research and Department of Molecular Genetics, The Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Johanne Pastor
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Danielle Carranza
- Banting and Best Department of Medical Research and Department of Molecular Genetics, The Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Henry Quiñones
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Carolyn Griffith
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Regina Goetz
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Moosa Mohammadi
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Jianfeng Ye
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jianning Zhang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ming Chang Hu
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Makoto Kuro-o
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Orson W Moe
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sachdev S Sidhu
- Banting and Best Department of Medical Research and Department of Molecular Genetics, The Donnelly Centre, University of Toronto, Toronto, ON, Canada
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278
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Sun Y, Zhou G, Gui T, Shimokado A, Nakanishi M, Oikawa K, Sato F, Muragaki Y. Elevated serum 1,25(OH)2-vitamin D3 level attenuates renal tubulointerstitial fibrosis induced by unilateral ureteral obstruction in kl/kl mice. Sci Rep 2014; 4:6563. [PMID: 25297969 PMCID: PMC5377451 DOI: 10.1038/srep06563] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 09/12/2014] [Indexed: 12/28/2022] Open
Abstract
Previous studies have suggested that Klotho provides reno-protection against unilateral ureteral obstruction (UUO)-induced renal tubulointerstitial fibrosis (RTF). Because the existing studies are mainly performed using heterozygous Klotho mutant (HT) mice, we focused on the effect of UUO on homozygous Klotho mutant (kl/kl) mice. UUO kidneys from HT mice showed a significantly higher level of RTF and TGF-β/Smad3 signaling than wild-type (WT) mice, whereas both were greatly suppressed in kl/kl mice. Primary proximal tubular epithelial culture cells isolated from kl/kl mice showed no suppression in TGF-β1-induced epithelial mesenchymal transition (EMT) compared to those from HT mice. In the renal epithelial cell line NRK52E, a large amount of inorganic phosphate (Pi), FGF23, or calcitriol was added to the medium to mimic the in vivo homeostasis of kl/kl mice. Neither Pi nor FGF23 antagonized TGF-β1-induced EMT. In contrast, calcitriol ameliorated TGF-β1-induced EMT in a dose dependent manner. A vitamin D3-deficient diet normalized the serum 1,25 (OH)2 vitamin D3 level in kl/kl mice and enhanced UUO-induced RTF and TGF-β/Smad3 signaling. In conclusion, the alleviation of UUO-induced RTF in kl/kl mice was due to the TGF-β1 signaling suppression caused by an elevated serum 1, 25(OH)2 vitamin D3.
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Affiliation(s)
- Yujing Sun
- 1] First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan [2] Department of Pathology, School of Medicine, Shandong University, Jinan Wen Hua Xi Road 44, Jinan 250012, PR China
| | - Gengyin Zhou
- Department of Pathology, School of Medicine, Shandong University, Jinan Wen Hua Xi Road 44, Jinan 250012, PR China
| | - Ting Gui
- 1] First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan [2]
| | - Aiko Shimokado
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Masako Nakanishi
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Kosuke Oikawa
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Fuyuki Sato
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
| | - Yasuteru Muragaki
- First Department of Pathology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-0012, Japan
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279
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Lindberg K, Amin R, Moe OW, Hu MC, Erben RG, Östman Wernerson A, Lanske B, Olauson H, Larsson TE. The kidney is the principal organ mediating klotho effects. J Am Soc Nephrol 2014; 25:2169-75. [PMID: 24854271 PMCID: PMC4178446 DOI: 10.1681/asn.2013111209] [Citation(s) in RCA: 214] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 02/26/2014] [Indexed: 12/14/2022] Open
Abstract
Klotho was discovered as an antiaging gene, and α-Klotho (Klotho) is expressed in multiple tissues with a broad set of biologic functions. Membrane-bound Klotho binds fibroblast growth factor 23 (FGF23), but a soluble form of Klotho is also produced by alternative splicing or cleavage of the extracellular domain of the membrane-bound protein. The relative organ-specific contributions to the levels and effects of circulating Klotho remain unknown. We explored these issues by generating a novel mouse strain with Klotho deleted throughout the nephron (Six2-KL(-/-)). Klotho shedding from Six2-KL(-/-) kidney explants was undetectable and the serum Klotho level was reduced by approximately 80% in Six2-KL(-/-) mice compared with wild-type littermates. Six2-KL(-/-) mice exhibited severe growth retardation, kyphosis, and premature death, closely resembling the phenotype of systemic Klotho knockout mice. Notable biochemical changes included hyperphosphatemia, hypercalcemia, hyperaldosteronism, and elevated levels of 1,25-dihydroxyvitamin D and Fgf23, consistent with disrupted renal Fgf23 signaling. Kidney histology demonstrated interstitial fibrosis and nephrocalcinosis in addition to absent dimorphic tubules. A direct comparative analysis between Six2-KL(-/-) and systemic Klotho knockout mice supports extensive, yet indistinguishable, extrarenal organ manifestations. Thus, our data reveal the kidney as the principal contributor of circulating Klotho and Klotho-induced antiaging traits.
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Affiliation(s)
- Karolina Lindberg
- Division of Renal Medicine, Department of Clinical Science, Intervention, and Technology, Karolinska Institutet, Stockholm Sweden
| | - Risul Amin
- Division of Renal Medicine, Department of Clinical Science, Intervention, and Technology, Karolinska Institutet, Stockholm Sweden
| | - Orson W Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Ming-Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Reinhold G Erben
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Annika Östman Wernerson
- Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Beate Lanske
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts; and
| | - Hannes Olauson
- Division of Renal Medicine, Department of Clinical Science, Intervention, and Technology, Karolinska Institutet, Stockholm Sweden
| | - Tobias E Larsson
- Division of Renal Medicine, Department of Clinical Science, Intervention, and Technology, Karolinska Institutet, Stockholm Sweden; Department of Nephrology, Karolinska University Hospital, Stockholm, Sweden
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280
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Staruschenko A. To cleave or not to cleave: role of ADAM17 in cell proliferation in PKD. Am J Physiol Renal Physiol 2014; 307:F658-9. [PMID: 25056345 DOI: 10.1152/ajprenal.00341.2014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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281
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Wolf I, Shahmoon S, Ben Ami M, Levy-Shraga Y, Mazor-Aronovitch K, Pinhas-Hamiel O, Yeshayahu Y, Hemi R, Kanety H, Rubinek T, Modan-Moses D. Association between decreased klotho blood levels and organic growth hormone deficiency in children with growth impairment. PLoS One 2014; 9:e107174. [PMID: 25198618 PMCID: PMC4157849 DOI: 10.1371/journal.pone.0107174] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 08/07/2014] [Indexed: 02/05/2023] Open
Abstract
Objective Klotho is an aging-modulating protein expressed mainly in the kidneys and choroid plexus, which can also be shed, released into the circulation and act as a hormone. Klotho deficient mice are smaller compared to their wild-type counterparts and their somatotropes show marked atrophy and reduced number of secretory granules. Recent data also indicated an association between klotho levels and growth hormone (GH) levels in acromegaly. We aimed to study the association between klotho levels and GH deficiency (GHD) in children with growth impairment. Design Prospective study comprising 99 children and adolescents (aged 9.0±3.7 years, 49 male) undergoing GH stimulation tests for short stature (height-SDS = −2.1±0.6). Klotho serum levels were measured using an α-klotho ELISA kit. Results Klotho levels were significantly lower (p<0.001) among children with organic GHD (n = 11, 727±273 pg/ml) compared to both GH sufficient participants (n = 59, 1497±754 pg/ml) and those with idiopathic GHD (n = 29, 1645±778 pg/ml). The difference between GHS children and children with idiopathic GHD was not significant. Klotho levels positively correlated with IGF-1- standard deviation scores (SDS) (R = 0.45, p<0.001), but were not associated with gender, pubertal status, age or anthropometric measurements. Conclusions We have shown, for the first time, an association between low serum klotho levels and organic GHD. If validated by additional studies, serum klotho may serve as novel biomarker of organic GHD.
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Affiliation(s)
- Ido Wolf
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shiri Shahmoon
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michal Ben Ami
- Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Yael Levy-Shraga
- Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Kineret Mazor-Aronovitch
- Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Orit Pinhas-Hamiel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Yonatan Yeshayahu
- Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Rina Hemi
- Institute of Endocrinology, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Hannah Kanety
- Institute of Endocrinology, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Tami Rubinek
- Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Dalit Modan-Moses
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
- * E-mail:
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282
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Park SJ, Chung YH, Lee JH, Dang DK, Nam Y, Jeong JH, Kim YS, Nabeshima T, Shin EJ, Kim HC. Growth Hormone-Releaser Diet Attenuates Cognitive Dysfunction in Klotho Mutant Mice via Insulin-Like Growth Factor-1 Receptor Activation in a Genetic Aging Model. Endocrinol Metab (Seoul) 2014; 29:336-48. [PMID: 25309793 PMCID: PMC4192803 DOI: 10.3803/enm.2014.29.3.336] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 11/26/2013] [Accepted: 12/13/2013] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND It has been recognized that a defect in klotho gene expression accelerates the degeneration of multiple age-sensitive traits. Accumulating evidence indicates that aging is associated with declines in cognitive function and the activity of growth hormone (GH)/insulin-like growth factor-1 (IGF-1). METHODS In this study, we examined whether a GH-releaser diet could be effective in protecting against cognitive impairment in klotho mutant mice. RESULTS The GH-releaser diet significantly induced the expression of IGF-1 and IGF-1 receptors in the hippocampus of klotho mutant mice. Klotho mutant mice showed significant memory impairments as compared with wild-type mice. In addition, the klotho mutation significantly decreased the expression of cell survival/antiapoptotic factors, including phospho-Akt (p-Akt)/phospho-glycogen synthase kinase3β (p-GSK3β), phospho-extracellular signal-related kinase (p-ERK), and Bcl-2, but significantly increased those of cell death/proapoptotic factors, such as phospho-c-jun N-terminal kinase (p-JNK), Bax, and cleaved caspase-3 in the hippocampus. Treatment with GH-releaser diet significantly attenuated both decreases in the expression of cell survival/antiapoptotic factors and increases in the expression of cell death/proapoptotic factors in the hippocampus of klotho mutant mice. In addition, klotho mutation-induced oxidative stress was significantly attenuated by the GH-releaser diet. Consequently, a GH-releaser diet significantly improved memory function in the klotho mutant mice. GH-releaser diet-mediated actions were significantly reversed by JB-1, an IGF-1 receptor antagonist. CONCLUSION The results suggest that a GH-releaser diet attenuates oxidative stress, proapoptotic changes and consequent dysfunction in klotho mutant mice by promoting IGF-1 expression and IGF-1 receptor activation.
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Affiliation(s)
- Seok Joo Park
- Neuropsychopharmacology and Toxicology Program, Kangwon National University College of Pharmacy, Chunchon, Korea
- Ilsong Institute of Life Science, Hallym University, Anyang, Korea
| | - Yoon Hee Chung
- Department of Anatomy, Chung-Ang University College of Medicine, Seoul, Korea
| | - Jeong Hyun Lee
- Neuropsychopharmacology and Toxicology Program, Kangwon National University College of Pharmacy, Chunchon, Korea
| | - Duy-Khanh Dang
- Neuropsychopharmacology and Toxicology Program, Kangwon National University College of Pharmacy, Chunchon, Korea
| | - Yunsung Nam
- Neuropsychopharmacology and Toxicology Program, Kangwon National University College of Pharmacy, Chunchon, Korea
- Department of Pharmacology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Ji Hoon Jeong
- Department of Pharmacology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Yong Sun Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Korea
| | - Toshitaka Nabeshima
- Department of Regional Pharmaceutical Care and Science, Meijo University Graduate School of Pharmaceutical Sciences, Nagoya, Japan
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, Kangwon National University College of Pharmacy, Chunchon, Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, Kangwon National University College of Pharmacy, Chunchon, Korea
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283
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Chen CD, Tung TY, Liang J, Zeldich E, Tucker Zhou TB, Turk BE, Abraham CR. Identification of cleavage sites leading to the shed form of the anti-aging protein klotho. Biochemistry 2014; 53:5579-87. [PMID: 25110992 PMCID: PMC4151695 DOI: 10.1021/bi500409n] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
![]()
Membrane
protein shedding is a critical step in many normal and
pathological processes. The anti-aging protein klotho (KL), mainly
expressed in kidney and brain, is secreted into the serum and CSF,
respectively. KL is proteolytically released, or shed, from the cell
surface by ADAM10 and ADAM17, which are the α-secretases that
also cleave the amyloid precursor protein and other proteins. The
transmembrane KL is a coreceptor with the FGF receptor for FGF23,
whereas the shed form acts as a circulating hormone. However, the
precise cleavage sites in KL are unknown. KL contains two major cleavage
sites: one close to the juxtamembrane region and another between the
KL1 and KL2 domains. We identified the cleavage site involved in KL
release by mutating potential sheddase(s) recognition sequences and
examining the production of the KL extracellular fragments in transfected
COS-7 cells. Deletion of amino acids T958 and L959 results in a 50–60%
reduction in KL shedding, and an additional P954E mutation results
in further reduction of KL shedding by 70–80%. Deletion of
amino acids 954–962 resulted in a 94% reduction in KL shedding.
This mutant also had moderately decreased cell surface expression,
yet had overall similar subcellular localization as that of WT KL,
as demonstrated by immunofluorescence. Cleavage-resistant mutants
could function as a FGFR coreceptor for FGF23, but they lost activity
as a soluble form of KL in proliferation and transcriptional reporter
assays. Cleavage between the KL1 and KL2 domains is dependent on juxtamembrane
cleavage. Our results shed light onto mechanisms underlying KL release
from the cell membrane and provide a target for potential pharmacologic
interventions aimed at regulating KL secretion.
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Affiliation(s)
- Ci-Di Chen
- Departments of Biochemistry, ‡Biology, and §Pharmacology and Experimental Therapeutics, Boston University School of Medicine , Boston, Massachusetts 02118, United States
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284
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Kim HJ, Lee J, Lee SY, Cheong HS, Kye YS, Kim W, Byun SS, Myung SC. The association between KL polymorphism and prostate cancer risk in Korean patients. Mol Biol Rep 2014; 41:7595-606. [PMID: 25120167 DOI: 10.1007/s11033-014-3647-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 07/27/2014] [Indexed: 02/07/2023]
Abstract
The Klotho (KL) gene is a classical "aging suppressor" gene. Although recent studies have shown that KL participates in the progression of several types of human cancers, the relationship between KL polymorphism and prostate cancer was unknown. The present study aimed to investigate the association between KL genetic polymorphisms and prostate cancer. Twenty-five common single nucleotide polymorphisms (SNPs) in KL gene (including KL gene polymorphism C1818T in exon 4) were assessed in 272 prostate cancer cases and 173 controls. Single-locus analyses were conducted using unconditional logistic regression. In addition, we did a haplotype analysis for the 25 KL SNPs tested. CC genotype of C1548T KL polymorphism had approximately twofold increased prostate cancer risk compared with the homozygous genotype TT and heterozygote CT (odds ratio 1.85 [95% CI, 1.09-3.12], P = 0.02). We also found that non-T allele carriers had significantly higher prostate cancer risk associated with the prostate cancer clinical characteristics (tumor stage or Gleason score). Our findings suggested that the C1548T polymorphism of KL gene is associated with the prostate cancer and may act as a risk factor for the development of prostate cancer.
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Affiliation(s)
- Hae Jong Kim
- Advanced Urogenital Disease Research Center, Chung-Ang University College of Medicine, Seoul, 156-756, Korea
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285
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Lee EY, Kim SS, Lee JS, Kim IJ, Song SH, Cha SK, Park KS, Kang JS, Chung CH. Soluble α-klotho as a novel biomarker in the early stage of nephropathy in patients with type 2 diabetes. PLoS One 2014; 9:e102984. [PMID: 25084095 PMCID: PMC4118846 DOI: 10.1371/journal.pone.0102984] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 06/24/2014] [Indexed: 01/25/2023] Open
Abstract
Objective Although α-klotho is known as an anti-aging, antioxidant, and cardio-renal protective protein, the clinical implications of soluble α-klotho levels in patients with diabetes have not been evaluated. Therefore, this study evaluated whether plasma and urinary α-klotho levels are associated with albuminuria in kidney disease in diabetes. Research Design and Methods A total of 147 patients with type 2 diabetes and 25 healthy control subjects were enrolled. The plasma and urine concentrations of α-klotho were analyzed by enzyme-linked immunosorbent assay. Results Plasma α-klotho (572.4 pg/mL [95% CI, 541.9–604.6 pg/mL] vs. 476.9 pg/mL [95% CI, 416.9–545.5 pg/mL]) and urinary α-klotho levels (59.8 pg/mg creatinine [95% CI, 43.6–82.0 pg/mg creatinine] vs. 21.0 pg/mg creatinine [95% CI, 9.7–45.6 pg/mg creatinine]) were significantly higher in diabetic patients than non-diabetic controls. Among diabetic patients, plasma α-klotho concentration was inversely associated with albuminuria stages (normoalbuminuria, 612.6 pg/mL [95% CI, 568.9–659.6 pg/mL], microalbuminuria, 551.8 pg/mL [95% CI, 500.5–608.3 pg/mL], and macroalbuminuria, 505.7 pg/mL [95% CI, 439.7–581.7 pg/mL] (p for trend = 0.0081), while urinary α-klotho levels were remained constantly high with increasing urinary albumin excretion. Conclusions Soluble α-klotho levels in plasma and urine may be novel and useful early markers of diabetic renal injury.
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Affiliation(s)
- Eun Young Lee
- Department of Internal Medicine, Soonchunhyang University Cheonan Hospital, Cheonan, Korea
- * E-mail:
| | - Sang Soo Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, Korea
| | - Ji-Sung Lee
- Biostatistical Consulting Unit, Soonchunhyang University Medical Center, Seoul, Korea
| | - In Joo Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, Korea
| | - Sang Heon Song
- Department of Internal Medicine, Pusan National University Hospital, Busan, Korea
| | - Seung-Kuy Cha
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Jeong Suk Kang
- Department of Internal Medicine, Soonchunhyang University Cheonan Hospital, Cheonan, Korea
| | - Choon Hee Chung
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
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286
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Shahmoon S, Rubinfeld H, Wolf I, Cohen ZR, Hadani M, Shimon I, Rubinek T. The aging suppressor klotho: a potential regulator of growth hormone secretion. Am J Physiol Endocrinol Metab 2014; 307:E326-34. [PMID: 24939736 DOI: 10.1152/ajpendo.00090.2014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Klotho is a transmembranal protein highly expressed in the kidneys, choroid plexus, and anterior pituitary. Klotho can also be cleaved and shed and acts as a circulating hormone. Klotho-deficient mice (kl/kl mice) develop a phenotype resembling early aging. Several lines of evidence suggest a role for klotho in the regulation of growth hormone (GH) secretion. The kl/kl mice are smaller compared with their wild-type counterparts, and their somatotropes show reduced numbers of secretory granules. Moreover, klotho is a potent inhibitor of the IGF-I pathway, a negative regulator of GH secretion. Therefore, we hypothesized that klotho may enhance GH secretion. The effect of klotho on GH secretion was examined in GH3 rat somatotrophs, cultured rat pituitaries, and cultured human GH-secreting adenomas. In all three models, klotho treatment increased GH secretion. Prolonged treatment of mice with intraperitoneal klotho injections increased mRNA levels of IGF-I and IGF-I-binding protein-3 mRNA in the liver, reflecting increased serum GH levels. In accord with its ability to inhibit the IGF-I pathway, klotho partially restored the inhibitory effect of IGF-I on GH secretion. Klotho is known to be a positive regulator of basic bFGF signaling. We studied rat pituitaries and human adenoma cultures and noted that bFGF increased GH secretion and stimulated ERK1/2 phosphorylation. Both effects were augmented following treatment with klotho. Taken together, our data indicate for the first time that klotho is a positive regulator of GH secretion and suggest the IGF-I and bFGF pathways as potential mediators of this effect.
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Affiliation(s)
- Shiri Shahmoon
- Institute of Oncology, Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hadara Rubinfeld
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Felsenstein Medical Research Center, Rabin Medical Center, Petach Tiqva, Israel; and
| | - Ido Wolf
- Institute of Oncology, Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Zvi R Cohen
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Neurosurgery, Sheba Medical Center, Tel-Hashomer, Israel
| | - Moshe Hadani
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Neurosurgery, Sheba Medical Center, Tel-Hashomer, Israel
| | - Ilan Shimon
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Felsenstein Medical Research Center, Rabin Medical Center, Petach Tiqva, Israel; and
| | - Tami Rubinek
- Institute of Oncology, Sourasky Medical Center, Tel Aviv, Israel;
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287
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Ravikumar P, Ye J, Zhang J, Pinch SN, Hu MC, Kuro-o M, Hsia CCW, Moe OW. α-Klotho protects against oxidative damage in pulmonary epithelia. Am J Physiol Lung Cell Mol Physiol 2014; 307:L566-75. [PMID: 25063799 DOI: 10.1152/ajplung.00306.2013] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
α-Klotho exerts pleiotropic biological actions. Heterozygous α-Klotho haplo-insufficient mice (kl/+) appear normal at baseline except for age-related changes in the lung, suggesting heightened pulmonary susceptibility to α-Klotho deficiency. We used in vivo and in vitro models to test whether α-Klotho protects lung epithelia against injury. Normally, α-Klotho is not expressed in the lung, but circulating α-Klotho levels are reduced -40% in kl/+ mice and undetectable in homozygous α-Klotho-deficient mice (kl/kl). kl/+ mice show distal air space enlargement at a given airway pressure, with elevated lung oxidative damage marker (8-hydroxydeoxyguanosine; 8-OHdG); these abnormalities are exacerbated in kl/kl mice. Studies were performed in A549 lung epithelial cells and/or primary culture of alveolar epithelial cells. Hyperoxia (95% O2) and high inorganic phosphate concentrations (Pi, 3-5 mM) additively caused cell injury (lactate dehydrogenase release), oxidative DNA damage (8-OHdG), lipid oxidation (8-isoprostane), protein oxidation (carbonyl), and apoptosis (caspase-8 activity and TUNEL stain). Transfection of transmembrane or soluble α-Klotho, or addition of soluble α-Klotho-containing conditioned media, increased cellular antioxidant capacity (Cu- and Fe-based assays) via increased nuclear factor erythroid-derived 2-related factors 1 and 2 (Nrf1/2) transcriptional activity and ameliorated hyperoxic and phosphotoxic injury. To validate the findings in vivo, we injected α-Klotho-containing conditioned media into rat peritoneum before and during hyperoxia exposure and found reduced alveolar interstitial edema and oxidative damage. We conclude that circulating α-Klotho protects the lung against oxidative damage and apoptosis partly via increasing endogenous antioxidative capacity in pulmonary epithelia. Cytoprotection by α-Klotho may play an important role in degenerative diseases of the lung.
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Affiliation(s)
- Priya Ravikumar
- Departments of Internal Medicine, Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jianfeng Ye
- Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | | | | | - Ming Chang Hu
- Departments of Internal Medicine, Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Makoto Kuro-o
- Pathology, Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | | | - Orson W Moe
- Departments of Internal Medicine, Physiology, and Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
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288
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Zeldich E, Chen CD, Colvin TA, Bove-Fenderson EA, Liang J, Tucker Zhou TB, Harris DA, Abraham CR. The neuroprotective effect of Klotho is mediated via regulation of members of the redox system. J Biol Chem 2014; 289:24700-15. [PMID: 25037225 DOI: 10.1074/jbc.m114.567321] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Generation of reactive oxygen species (ROS), leading to oxidative damage and neuronal cell death, plays an important role in the pathogenesis of neurodegenerative disorders, including Alzheimer disease. The present study aimed to examine the mechanism by which the anti-aging protein Klotho exerts neuroprotective effects against neuronal damage associated with neurodegeneration and oxidative stress. Pretreatment of rat primary hippocampal neurons and mouse hippocampal neuronal cell line HT22 with recombinant Klotho protected these cells from glutamate and oligomeric amyloid β (oAβ)-induced cytotoxicity. In addition, primary hippocampal neurons obtained from Klotho-overexpressing mouse embryos were more resistant to both cytotoxic insults, glutamate and oAβ, compared with neurons from wild-type littermates. An antioxidative stress array analysis of neurons treated with Klotho revealed that Klotho significantly enhances the expression of the thioredoxin/peroxiredoxin (Trx/Prx) system with the greatest effect on the induction of Prx-2, an antioxidant enzyme, whose increase was confirmed at the mRNA and protein levels. Klotho-induced phosphorylation of the PI3K/Akt pathway, a pathway important in apoptosis and longevity, was associated with sustained inhibitory phosphorylation of the transcription factor forkhead box O3a (FoxO3a) and was essential for the induction of Prx-2. Down-regulation of Prx-2 expression using a lentivirus harboring shRNA almost completely abolished the ability of Klotho to rescue neurons from glutamate-induced death and significantly, but not completely, inhibited cell death mediated by oAβ, suggesting that Prx-2 is a key modulator of neuroprotection. Thus, our results demonstrate, for the first time, the neuroprotective role of Klotho and reveal a novel mechanism underlying this effect.
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Affiliation(s)
| | | | | | | | | | - Tracey B Tucker Zhou
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts 02118
| | | | - Carmela R Abraham
- From the Department of Biochemistry, Program in Molecular Medicine, and Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts 02118
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289
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Razzaque MS. Bone-kidney axis in systemic phosphate turnover. Arch Biochem Biophys 2014; 561:154-8. [PMID: 24997362 DOI: 10.1016/j.abb.2014.06.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 06/18/2014] [Accepted: 06/24/2014] [Indexed: 12/20/2022]
Abstract
An adequate phosphate balance is essential for the maintenance of skeletal growth, development and function. It is also crucial in basic cellular functions, ranging from cell signaling to energy metabolism. Bone-derived fibroblast growth factor 23 (FGF23), through activating FGF receptor system, plays an important role in the systemic regulation of phosphate metabolism. Under physiological conditions, FGF23 exerts serum phosphate-lowering effects by inducing urinary phosphate excretion. Increased FGF23 activities are associated with hypophosphatemic diseases (i.e., rickets/osteomalacia), while reduced FGF23 activity are linked to hyperphosphatemic diseases (i.e., tumoral calcinosis). Unlike most of the FGF family members, FGF23 needs klotho, as a co-factor to activate its receptor system. In vivo studies have convincingly demonstrated that, in absence of klotho, FGF23 is unable to influence systemic phosphate metabolism. Available information suggests that interactions of FGF23, klotho, and FGFRs regulate renal phosphate metabolism by suppressing sodium-phosphate transporters in the proximal tubular epithelial cells. This article briefly summarizes how bone-kidney communication contributes to physiologic phosphate balance.
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Affiliation(s)
- Mohammed Shawkat Razzaque
- Department of Applied Oral Sciences, The Forsyth Institute, 245 First Street, Cambridge, MA 02142, USA.
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290
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Avin KG, Coen PM, Huang W, Stolz DB, Sowa GA, Dubé JJ, Goodpaster BH, O'Doherty RM, Ambrosio F. Skeletal muscle as a regulator of the longevity protein, Klotho. Front Physiol 2014; 5:189. [PMID: 24987372 PMCID: PMC4060456 DOI: 10.3389/fphys.2014.00189] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 04/29/2014] [Indexed: 01/06/2023] Open
Abstract
Klotho is a powerful longevity protein that has been linked to the prevention of muscle atrophy, osteopenia, and cardiovascular disease. Similar anti-aging effects have also been ascribed to exercise and physical activity. While an association between muscle function and Klotho expression has been previously suggested from longitudinal cohort studies, a direct relationship between circulating Klotho and skeletal muscle has not been investigated. In this paper, we present a review of the literature and preliminary evidence that, together, suggests Klotho expression may be modulated by skeletal muscle activity. Our pilot clinical findings performed in young and aged individuals suggest that circulating Klotho levels are upregulated in response to an acute exercise bout, but that the response may be dependent on fitness level. A similar upregulation of circulating Klotho is also observed in response to an acute exercise in young and old mice, suggesting that this may be a good model for mechanistically probing the role of physical activity on Klotho expression. Finally, we highlight overlapping signaling pathways that are modulated by both Klotho and skeletal muscle and propose potential mechanisms for cross-talk between the two. It is hoped that this review will stimulate further consideration of the relationship between skeletal muscle activity and Klotho expression, potentially leading to important insights into the well-documented systemic anti-aging effects of exercise.
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Affiliation(s)
- Keith G Avin
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh Pittsburgh, PA, USA ; Division of Geriatric Medicine, Department of Medicine, University of Pittsburgh PA, USA
| | - Paul M Coen
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh Pittsburgh, PA, USA ; Department of Health and Physical Education, University of Pittsburgh Pittsburgh, PA, USA
| | - Wan Huang
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh Pittsburgh, PA, USA
| | - Donna B Stolz
- Department of Cell Biology and Physiology, University of Pittsburgh Pittsburgh, PA, USA
| | - Gwendolyn A Sowa
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh Pittsburgh, PA, USA
| | - John J Dubé
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh Pittsburgh, PA, USA
| | - Bret H Goodpaster
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh Pittsburgh, PA, USA
| | - Robert M O'Doherty
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh Pittsburgh, PA, USA
| | - Fabrisia Ambrosio
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh Pittsburgh, PA, USA ; McGowan Institute for Regenerative Medicine, University of Pittsburgh Pittsburgh, PA, USA
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291
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The anti-aging and tumor suppressor protein Klotho enhances differentiation of a human oligodendrocytic hybrid cell line. J Mol Neurosci 2014; 55:76-90. [PMID: 24907942 DOI: 10.1007/s12031-014-0336-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 05/16/2014] [Indexed: 12/12/2022]
Abstract
Klotho functions as an aging suppressor, which, in mice, extends lifespan when overexpressed and accelerates development of aging-like phenotypes when disrupted. Klotho is mainly expressed in brain and kidney and is secreted into the serum and CSF. We have previously shown that Klotho is reduced in brains of old monkeys, rats, and mice. We further reported the ability of Klotho to enhance oligodendrocyte differentiation and myelination. Here, we examined the signaling pathways induced by Klotho in MO3.13, a human oligodendrocytic hybrid cell line. We show that exogenous Klotho affects the ERK and Akt signaling pathways, decreases the proliferative abilities and enhances differentiation of MO3.13 cells. Furthermore, microarray analysis of Klotho-treated MO3.13 cells reveals a massive change in gene expression with 80 % of the differentially expressed genes being downregulated. Using gene set enrichment analysis, we predicted potential transcription factors involved in regulating Klotho-treated MO3.13 cells and found that these cells are highly enriched in the gene sets, that are similarly observed in cancer, cardiovascular disease, stress, aging, and hormone-related chemical and genetic perturbations. Since Klotho is downregulated in all brain tumors tested to date, enhancing Klotho has therapeutic potential for treating brain and other malignancies.
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292
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Dubal DB, Yokoyama JS, Zhu L, Broestl L, Worden K, Wang D, Sturm VE, Kim D, Klein E, Yu GQ, Ho K, Eilertson KE, Yu L, Kuro-o M, De Jager PL, Coppola G, Small GW, Bennett DA, Kramer JH, Abraham CR, Miller BL, Mucke L. Life extension factor klotho enhances cognition. Cell Rep 2014; 7:1065-76. [PMID: 24813892 PMCID: PMC4176932 DOI: 10.1016/j.celrep.2014.03.076] [Citation(s) in RCA: 196] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 01/10/2014] [Accepted: 03/31/2014] [Indexed: 12/22/2022] Open
Abstract
Aging is the primary risk factor for cognitive decline, an emerging health threat to aging societies worldwide. Whether anti-aging factors such as klotho can counteract cognitive decline is unknown. We show that a lifespan-extending variant of the human KLOTHO gene, KL-VS, is associated with enhanced cognition in heterozygous carriers. Because this allele increased klotho levels in serum, we analyzed transgenic mice with systemic overexpression of klotho. They performed better than controls in multiple tests of learning and memory. Elevating klotho in mice also enhanced long-term potentiation, a form of synaptic plasticity, and enriched synaptic GluN2B, an N-methyl-D-aspartate receptor (NMDAR) subunit with key functions in learning and memory. Blockade of GluN2B abolished klotho-mediated effects. Surprisingly, klotho effects were evident also in young mice and did not correlate with age in humans, suggesting independence from the aging process. Augmenting klotho or its effects may enhance cognition and counteract cognitive deficits at different life stages.
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Affiliation(s)
- Dena B Dubal
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Jennifer S Yokoyama
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Lei Zhu
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Lauren Broestl
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kurtresha Worden
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Dan Wang
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Virginia E Sturm
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Daniel Kim
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Eric Klein
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90024, USA
| | - Gui-Qiu Yu
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Kaitlyn Ho
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | | | - Lei Yu
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA
| | - Makoto Kuro-o
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Center for Molecular Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Philip L De Jager
- Program in Translational NeuroPsychiatric Genomics, Institute for Neurosciences, Departments of Neurology & Psychiatry, Brigham and Women's Hospital, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA 02142, USA
| | - Giovanni Coppola
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90024, USA
| | - Gary W Small
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90024, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA
| | - Joel H Kramer
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Carmela R Abraham
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Bruce L Miller
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.
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293
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Jiang B, Gu Y, Chen Y. Identification of Novel Predictive Markers for the Prognosis of Pancreatic Ductal Adenocarcinoma. Cancer Invest 2014; 32:218-25. [DOI: 10.3109/07357907.2014.905586] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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294
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He XJ, Ma YY, Yu S, Jiang XT, Lu YD, Tao L, Wang HP, Hu ZM, Tao HQ. Up-regulated miR-199a-5p in gastric cancer functions as an oncogene and targets klotho. BMC Cancer 2014; 14:218. [PMID: 24655788 PMCID: PMC3994330 DOI: 10.1186/1471-2407-14-218] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 03/12/2014] [Indexed: 12/14/2022] Open
Abstract
Background Recent studies have shown that miR-199a-5p plays opposite roles in cancer initiation and progression of different cancer types, acting as oncogene for some cancer types but as tumor suppressor gene for others. However, the role and molecular mechanism of miR-199a-5p in gastric cancer are largely unknown. Methods In this study, miR-199a-5p expression level in gastric cancer was first analyzed by qPCRand then validated in 103 gastric cancer patients by in situ hybridization (ISH). Gastric cancer cell lines were transfected with miR-199a-5p inhibitor and mimic, and underwent in vitro transwell assays. Target genes (klotho) were identified using Luciferase reporter assay. Immunohistochemical staining was also used to investigate on how miR-199a-5p regulates the tumour-suppressive effects of klotho in gastric cancer. Results In our present study, we found that miR-199a-5p level was significantly increased in gastric cancer tissues compared to paired normal tissues. We observed that miR-199a-5p could promote migration and invasion of gastric cancer cells. In situ hybridization of miR-199a-5p also confirmed that higher miR-199a-5p expression level was associated with increased likelihood of lymph node metastasis and later TNM stage. Luciferase reporter assay and immunohistochemistry revealed that klotho might be the downstream target of miR-199a-5p. Conclusions Our present study suggests that miR-199a-5p acts as an oncogene in gastric cancer and functions by targeting klotho.
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Affiliation(s)
| | | | | | | | | | | | | | - Zhi-Ming Hu
- Key Laboratory of Gastroenterology of Zhejiang Province, Zhejiang Provincial People's Hospital, Hangzhou 310014, China.
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295
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Mehi SJ, Maltare A, Abraham CR, King GD. MicroRNA-339 and microRNA-556 regulate Klotho expression in vitro. AGE (DORDRECHT, NETHERLANDS) 2014; 36:141-149. [PMID: 23818104 PMCID: PMC3889880 DOI: 10.1007/s11357-013-9555-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 06/18/2013] [Indexed: 06/02/2023]
Abstract
Klotho is an anti-aging protein with direct effects on life-span in mice. Klotho functions to regulate pathways classically associated with longevity including insulin/IGF1 and Wnt signaling. Decreased Klotho protein expression is observed throughout the body during the normal aging process. While increased methylation of the Klotho promoter is reported, other epigenetic mechanisms could contribute to age-related downregulation of Klotho expression, including microRNA-mediated regulation. Following in silico identification of potential microRNA binding sites within the Klotho 3' untranslated region, reporter assays reveal regulation by microRNA-339, microRNA-556, and, to a lesser extent, microRNA-10 and microRNA-199. MicroRNA-339 and microRNA-556 were further found to directly decrease Klotho protein expression indicating that, if upregulated in aging tissue, these microRNA could play a role in age-related downregulation of Klotho messenger RNA. These microRNAs are differentially regulated in cancer cells compared to normal cells and may imply a role for microRNA-mediated regulation of Klotho in cancer.
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Affiliation(s)
- Stephen J. Mehi
- />Department of Neurobiology, University of Alabama at Birmingham, 1825 University Blvd, Shelby Building 913, Birmingham, AL 35294 USA
| | - Astha Maltare
- />Department of Neurobiology, University of Alabama at Birmingham, 1825 University Blvd, Shelby Building 913, Birmingham, AL 35294 USA
| | - Carmela R. Abraham
- />Department of Biochemistry, Boston University School of Medicine, 72 East Concord Street K304, Boston, MA 02118 USA
| | - Gwendalyn D. King
- />Department of Neurobiology, University of Alabama at Birmingham, 1825 University Blvd, Shelby Building 913, Birmingham, AL 35294 USA
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296
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Reduced renal α-Klotho expression in CKD patients and its effect on renal phosphate handling and vitamin D metabolism. PLoS One 2014; 9:e86301. [PMID: 24466013 PMCID: PMC3900516 DOI: 10.1371/journal.pone.0086301] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 12/06/2013] [Indexed: 11/22/2022] Open
Abstract
Renal α-Klotho (α-KL) plays a fundamental role as a co-receptor for fibroblast growth factor 23 (FGF23), a phosphaturic hormone and regulator of 1,25(OH)2 vitamin D3 (1,25VitD3). Disruption of FGF23-α-KL signaling is thought to be an early hallmark of chronic kidney disease (CKD) involving reduced renal α-KL expression and a reciprocal rise in serum FGF23. It remains unclear, however, whether the rise in FGF23 is related to the loss of renal α-KL. We evaluated α-KL expression in renal biopsy samples and measured levels of several parameters of mineral metabolism, as well as soluble α-KL (sKL), in serum and urinary samples from CKD patients (n = 236). We found that although renal α-KL levels were significantly reduced and serum FGF23 levels were significantly elevated in early and intermediate CKD, serum phosphate levels remained within the normal range. Multiple regression analysis showed that the increases in FGF23 were significantly associated with reduced renal function and elevated serum phosphate, but were not associated with loss of renal α-KL. Moreover, despite falling renal α-KL levels, the increase in FGF23 enhanced urinary fractional excretion of phosphate and reduced serum 1,25VitD3 levels in early and intermediate CKD, though not in advanced CKD. Serum sKL levels also fell significantly over the course of CKD, and renal α-KL was a significant independent determinant of sKL. These results demonstrate that FGF23 levels rise to compensate for renal failure-related phosphate retention in early and intermediate CKD. This enables FGF23-α-KL signaling and a neutral phosphate balance to be maintained despite the reduction in α-KL. In advanced CKD, however, renal α-KL declines further. This disrupts FGF23 signaling, and serum phosphate levels significantly increase, stimulating greater FGF23 secretion. Our results also suggest the serum sKL concentration may be a useful marker of renal α-KL expression levels.
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297
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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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298
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Tucker Zhou TB, King GD, Chen C, Abraham CR. Biochemical and functional characterization of the klotho-VS polymorphism implicated in aging and disease risk. J Biol Chem 2013; 288:36302-11. [PMID: 24217253 PMCID: PMC3868745 DOI: 10.1074/jbc.m113.490052] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 11/06/2013] [Indexed: 12/14/2022] Open
Abstract
Klotho (KL) is an age-regulating protein named after the Greek goddess who spins the thread of life. Mice deficient in KL are normal throughout development, but rapidly degenerate and display a variety of aging-associated abnormalities that eventually lead to decreased life expectancy. While multiple genetic association studies have identified KL polymorphisms linked with changes in disease risk, there is a paucity of concrete mechanistic data to explain how these amino acid substitutions alter KL protein function. The KLVS polymorphism is suggested to lead to changes in protein trafficking although the mechanism is unclear. Our studies have sought to further investigate the functional differences in the KLVS variant that result in increased risk of many age-related diseases. Our findings suggest that the F352V and C370S substitutions lead to alterations in processing as seen by differences in shedding and half-life. Their co-expression in KLVS results in a phenotype resembling wild-type, but despite this intragenic complementation there are still changes in homodimerization and interactions with FGFR1c. Taken together, these studies suggest that KLVS leads to altered homodimerization that indirectly leads to changes in processing and FGFR1c interactions. These findings help elucidate the functional differences that result from the VS polymorphism, which will help clarify how alterations in KL function can lead to human disease and affect cognition and lifespan.
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Affiliation(s)
- Tracey B. Tucker Zhou
- From the Departments of Pharmacology and Experimental Therapeutics and
- Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Gwendalyn D. King
- From the Departments of Pharmacology and Experimental Therapeutics and
| | - CiDi Chen
- From the Departments of Pharmacology and Experimental Therapeutics and
| | - Carmela R. Abraham
- From the Departments of Pharmacology and Experimental Therapeutics and
- Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
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299
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Matsubara T, Miyaki A, Akazawa N, Choi Y, Ra SG, Tanahashi K, Kumagai H, Oikawa S, Maeda S. Aerobic exercise training increases plasma Klotho levels and reduces arterial stiffness in postmenopausal women. Am J Physiol Heart Circ Physiol 2013; 306:H348-55. [PMID: 24322608 DOI: 10.1152/ajpheart.00429.2013] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Klotho gene is a suppressor of the aging phenomena, and the secretion as well as the circulation of Klotho proteins decrease with aging. Although habitual exercise has antiaging effects (e.g., a decrease in arterial stiffness), the relationship between Klotho and habitual exercise remains unclear. In the present study, we investigated the effect of habitual exercise on Klotho, with a particular focus on arterial stiffness. First, we examined the correlation between plasma Klotho concentration and arterial stiffness (carotid artery compliance and β-stiffness index) or aerobic exercise capacity [oxygen uptake at ventilatory threshold (VT)] in 69 healthy, postmenopausal women (50-76 years old) by conducting a cross-sectional study. Second, we tested the effects of aerobic exercise training on plasma Klotho concentrations and arterial stiffness. A total of 19 healthy, postmenopausal women (50-76 years old) were divided into two groups: control group and exercise group. The exercise group completed 12 wk of moderate aerobic exercise training. In the cross-sectional study, plasma Klotho concentrations positively correlated with carotid artery compliance and VT and negatively correlated with the β-stiffness index. In the interventional study, aerobic exercise training increased plasma Klotho concentrations and carotid artery compliance and decreased the β-stiffness index. Moreover, the changes in plasma Klotho concentration and arterial stiffness were found to be correlated. These results suggest a possible role for secreted Klotho in the exercise-induced modulation of arterial stiffness.
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Affiliation(s)
- Tomoko Matsubara
- Division of Sports Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
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Klotho has dual protective effects on cisplatin-induced acute kidney injury. Kidney Int 2013; 85:855-70. [PMID: 24304882 PMCID: PMC3972320 DOI: 10.1038/ki.2013.489] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 09/11/2013] [Accepted: 09/19/2013] [Indexed: 02/07/2023]
Abstract
Klotho protects the kidney from ischemia-reperfusion injury, but its effect on nephrotoxins is unknown. Here we determined whether Klotho protects the kidney from cisplatin toxicity. Cisplatin increased plasma creatinine and induced tubular injury, which were exaggerated in Klotho haplosufficient (Kl/+) and ameliorated in transgenic Klotho overexpressing (Tg-Kl) mice. Neutrophil gelatinase-associated lipocalin and active caspase-3 protein and the number of apoptotic cells in the kidney were higher in Kl/+ and lower in Tg-Kl compared with wild-type mice. Klotho suppressed basolateral uptake of cisplatin by the normal rat kidney cell line (NRK), an effect similar to cimetidine, a known inhibitor of organic cation transport (OCT). A decrease in cell surface and total OCT2 protein and OCT activity by Klotho was mimicked by β-glucuronidase. The Klotho effect was attenuated by β-glucuronidase inhibition. On the other hand, OCT2 mRNA was reduced by Klotho but not by β-glucuronidase. Moreover, cimetidine inhibited OCT activity but not OCT2 expression. Unlike cimetidine, Klotho reduced cisplatin-induced apoptosis from either the basolateral or apical side and even when added after NRK cells were already loaded with cisplatin. Thus, Klotho protects the kidney against cisplatin nephrotoxicity by reduction of basolateral uptake of cisplatin by OCT2 and a direct anti-apoptotic effect independent of cisplatin uptake. Klotho may be a useful agent to prevent and treat cisplatin-induced nephrotoxicity.
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