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Neyra JA, Hu MC. Potential application of klotho in human chronic kidney disease. Bone 2017; 100:41-49. [PMID: 28115282 PMCID: PMC5474175 DOI: 10.1016/j.bone.2017.01.017] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 01/18/2017] [Accepted: 01/18/2017] [Indexed: 01/13/2023]
Abstract
The extracellular domain of transmembrane alpha-Klotho (αKlotho, hereinafter simply called Klotho) is cleaved by secretases and released into the circulation as soluble Klotho. Soluble Klotho in the circulation starts to decline early in chronic kidney disease (CKD) stage 2 and urinary Klotho possibly even earlier in CKD stage 1. Therefore soluble Klotho could serve as an early and sensitive marker of kidney function decline. Moreover, preclinical animal data support Klotho deficiency is not just merely a biomarker, but a pathogenic factor for CKD progression and extrarenal CKD complications including cardiovascular disease and disturbed mineral metabolism. Prevention of Klotho decline, re-activation of endogenous Klotho production or supplementation of exogenous Klotho are all associated with attenuation of renal fibrosis, retardation of CKD progression, improvement of mineral metabolism, amelioration of cardiomyopathy, and alleviation of vascular calcification in CKD. Therefore Klotho is not only a diagnostic and/or prognostic marker for CKD, but the treatment of Klotho deficiency may be a promising strategy to prevent, retard, and decrease the burden of comorbidity in CKD.
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Affiliation(s)
- Javier A Neyra
- Department of Internal Medicine, University of Texas Southwestern Medical Center, USA; Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, USA
| | - Ming Chang Hu
- Department of Internal Medicine, University of Texas Southwestern Medical Center, USA; Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, USA.
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Drew DA, Katz R, Kritchevsky S, Ix J, Shlipak M, Gutiérrez OM, Newman A, Hoofnagle A, Fried L, Semba RD, Sarnak M. Association between Soluble Klotho and Change in Kidney Function: The Health Aging and Body Composition Study. J Am Soc Nephrol 2017; 28:1859-1866. [PMID: 28104822 PMCID: PMC5461794 DOI: 10.1681/asn.2016080828] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/10/2016] [Indexed: 11/03/2022] Open
Abstract
CKD appears to be a condition of soluble klotho deficiency. Despite known associations between low soluble klotho levels and conditions that promote kidney damage, such as oxidative stress and fibrosis, little information exists regarding the longitudinal association between soluble klotho levels and change in kidney function. We assayed serum soluble α-klotho in 2496 participants within the Health Aging and Body Composition study, a cohort of older adults. The associations between soluble klotho levels and decline in kidney function (relative decline: eGFR decline ≥30%; absolute decline: eGFR decline >3 ml/min per year) and incident CKD (incident eGFR <60 ml/min per 1.73 m2 and >1 ml/min per year decline) were evaluated. We adjusted models for demographics, baseline eGFR, urine albumin-to-creatinine ratio, comorbidity, and measures of mineral metabolism. Among participants, the mean (SD) age was 75 (3) years, 52% were women, and 38% were black. Median (25th, 75th percentiles) klotho level was 630 (477, 817) pg/ml. In fully adjusted models, each two-fold higher level of klotho associated with lower odds of decline in kidney function (odds ratio, 0.78 [95% confidence interval, 0.66 to 0.93] for 30% decline in eGFR, and 0.85 [95% confidence interval, 0.73 to 0.98] for >3 ml/min per year decline in eGFR), but not of incident CKD (incident rate ratio, 0.90 [95% confidence interval, 0.78 to 1.04]). Overall, a higher soluble klotho level independently associated with a lower risk of decline in kidney function. Future studies should attempt to replicate these results in other cohorts and evaluate the underlying mechanism.
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Affiliation(s)
- David A Drew
- Department of Medicine, Division of Nephrology, Tufts Medical Center, Boston, Massachusetts;
| | - Ronit Katz
- Kidney Research Institute, Division of Nephrology, University of Washington, Seattle, Washington
| | - Stephen Kritchevsky
- Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Wake Forest University, Winston-Salem, North Carolina
| | - Joachim Ix
- Division of Nephrology-Hypertension, Department of Medicine, University of California San Diego, San Diego, CA and Nephrology Section, Veterans Affairs San Diego Healthcare System, La Jolla, California
| | - Michael Shlipak
- Kidney Health Research Collaborative, San Francisco VA Medical Center and University of California, San Francisco, San Francisco, California; Departments of
| | - Orlando M Gutiérrez
- Medicine and
- Epidemiology, University of Alabama School of Medicine, Birmingham, Alabama
| | - Anne Newman
- Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania
| | - Andy Hoofnagle
- Kidney Research Institute, Division of Nephrology, University of Washington, Seattle, Washington
| | - Linda Fried
- Kidney Research Institute, Division of Nephrology, University of Washington, Seattle, Washington
- Kidney Research Institute, Division of Nephrology, University of Washington, Seattle, Washington
- Renal Section, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania and
| | - Richard D Semba
- Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Mark Sarnak
- Department of Medicine, Division of Nephrology, Tufts Medical Center, Boston, Massachusetts
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Friedl C, Zitt E. Vitamin D prohormone in the treatment of secondary hyperparathyroidism in patients with chronic kidney disease. Int J Nephrol Renovasc Dis 2017; 10:109-122. [PMID: 28546765 PMCID: PMC5436758 DOI: 10.2147/ijnrd.s97637] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Secondary hyperparathyroidism (sHPT) represents the adaptive and very often, finally, maladaptive response of the organism to control the disturbed homeostasis of calcium, phosphorus, and vitamin D metabolism caused by declining renal function in chronic kidney disease (CKD). sHPT leads to cardiovascular and extravascular calcifications and is directly linked to an increased risk of cardiovascular morbidity and mortality as well as excess all-cause mortality. Vitamin D plays an important role in the development of sHPT. CKD patients are characterized by a high prevalence of hypovitaminosis D. Supplementation with both vitamin D prohormones cholecalciferol and ergocalciferol enables the achievement and maintenance of a normal vitamin D status when given in adequate doses over an appropriate treatment period. In patients with earlier stages of CKD, sHPT is influenced by and can be successfully treated with vitamin D prohormone supplementation, whereas in patients with very late stages of CKD and those requiring dialysis, treatment with prohormones seems to be of limited efficacy. This review gives an overview of the pathogenesis of sHPT, summarizes vitamin D metabolism, and discusses the existing literature regarding the role of vitamin D prohormone in the treatment of sHPT in patients with CKD.
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Affiliation(s)
- Claudia Friedl
- Department of Internal Medicine, Clinical Division of Nephrology, Medical University of Graz, Graz
| | - Emanuel Zitt
- Department of Nephrology and Dialysis, Feldkirch Academic Teaching Hospital, Feldkirch, Austria
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54
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Fakhar M, Rashid S. Targeted inhibition of Klotho binding to fibroblast growth factor 23 prevents hypophosphetemia. J Mol Graph Model 2017; 75:9-19. [PMID: 28501532 DOI: 10.1016/j.jmgm.2017.04.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 04/13/2017] [Accepted: 04/18/2017] [Indexed: 02/08/2023]
Abstract
Klotho is a transmembrane protein which plays significant role in the pathogenesis of phosphate ion (Pi)-related disorders. Pi accumulation in human kidney tissues results in the major metabolic disorders due to malfunctioning of Klotho-FGFR1-FGF23 trimeric complex. The potential role of Klotho in Pi metabolism was elaborated through modeling and interaction analysis of glycosyl hydrolase (GS1 and GS2) domains with Fibroblast growth factor 23 (FGF23). In order to inhibit the association of Klotho and FGF23, binding patterns of three reported hits (N-(2-chlorophenyl)-1H-indole-3-carboxamide, N-[2-(1-cyclohexen-1-yl)ethyl]-6,7,8,9-tetrahydropyrido[1,2-e]purin-4-amine and 2-(1-propyl)amino-11-chlorothiazolo[5,4-a]acridine) were evaluated through molecular docking analysis. These inhibitors effectively targeted both GS1 and GS2 domains of Klotho at the similar sites required for FGF23 binding. To further characterize the comparative binding profile of these compounds, molecular dynamics simulation assays were performed. Taken together, current study emphasizes that Klotho may be anticipated as a target molecule in familial hypophosphatemic rickets and mentioned compounds may prove to be effective therapeutic targets against hypophosphetemia induced disorders.
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Affiliation(s)
- Muhammad Fakhar
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan
| | - Sajid Rashid
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan.
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Lin W, Zhang Q, Liu L, Yin S, Liu Z, Cao W. Klotho restoration via acetylation of Peroxisome Proliferation-Activated Receptor γ reduces the progression of chronic kidney disease. Kidney Int 2017; 92:669-679. [PMID: 28416226 DOI: 10.1016/j.kint.2017.02.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 02/09/2017] [Accepted: 02/16/2017] [Indexed: 02/06/2023]
Abstract
Klotho is an anti-aging protein mainly expressed in the kidney. Reduced Klotho expression closely correlates with the development and progression of chronic kidney disease (CKD). Klotho is also a downstream gene of Peroxisome Proliferation-Activated Receptor γ (PPARγ), a major transcription factor whose functions are significantly affected by post-translational modifications including acetylation. However, whether PPARγ acetylation regulates renal Klotho expression and function in CKD is unknown. Here we test whether renal damage and reduced Klotho expression in the adenine CKD mouse model can be attenuated by the pan histone deacetylase (HDAC) inhibitor trichostatin A. This inhibition up-regulated Klotho mainly through an enhancement of PPARγ acetylation, stimulation of PPARγ binding to Klotho promoter, and PPARγ-dependent increase in Klotho transcription, with a substantial control of the regulation occurring via PPARγ acetylations on K240 and K265. Consistently trichostatin A-induced reversal of Klotho loss and renoprotective effects were abrogated in PPARγ knockout mice, supporting that PPARγ is an essential acetylation target for Klotho restoration and renal protection. Intriguingly, the kidneys of adenine-fed CKD mice displayed deregulated HDAC3 up-regulation. Selective HDAC3 inhibition effectively alleviated Klotho loss and kidney injury, whereas the protective effects were largely abolished when Klotho was knocked down by siRNA, suggesting that aberrant HDAC3 and Klotho loss are crucial components involved in the renal damage of mice with CKD. Our study identified an important signaling cascade and key components contributing to the pathogenesis of CKD. Thus, targeting Klotho loss by HDAC3 inhibition has promising therapeutic potential for the reduction of CKD progression.
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Affiliation(s)
- Wenjun Lin
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Qin Zhang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Lin Liu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Shasha Yin
- Department of Basic Medical Science and Jiangsu Key Lab of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China
| | - Zhihong Liu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
| | - Wangsen Cao
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China; Department of Basic Medical Science and Jiangsu Key Lab of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China.
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56
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Nie F, Wu D, Du H, Yang X, Yang M, Pang X, Xu Y. Serum klotho protein levels and their correlations with the progression of type 2 diabetes mellitus. J Diabetes Complications 2017; 31:594-598. [PMID: 27916483 DOI: 10.1016/j.jdiacomp.2016.11.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/24/2016] [Accepted: 11/05/2016] [Indexed: 12/11/2022]
Abstract
AIM To investigate the associations of serum α-Klotho and β-Klotho levels with type 2 diabetes mellitus (T2DM) progression. METHODS We evaluated 106 healthy controls and 261 cases of T2DM with or without diabetic complications (range: 45-84years). Serum α-Klotho and β-Klotho levels were analyzed using enzyme-linked immunosorbent assays. RESULTS Compared to the healthy controls, α-Klotho and β-Klotho levels were significantly lower among patients with T2DM and with or without diabetic complications (P<0.05). Furthermore, α-Klotho levels were lower in the microalbuminuric and macroalbuminuric groups, compared to the normoalbuminuric group. However, β-Klotho levels were only lower in the macroalbuminuric group (P<0.05). Multiple linear regression analyses revealed that α-Klotho and β-Klotho levels were positively correlated with the creatinine clearance rate, and negatively correlated with the urinary albumin to creatinine ratio and randomly sampled serum levels of creatinine, blood urea nitrogen, and blood glucose. Moreover, α-Klotho and β-Klotho levels were positively correlated among patients with T2DM (r=0.693, P<0.001). CONCLUSIONS Serum levels of α-Klotho and β-Klotho are down-regulated in patients with T2DM. Thus, these proteins may participate in the pathological mechanism of diabetes, and the positive correlation of α-Klotho and β-Klotho levels indicates that they might have similar mechanisms in T2DM.
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Affiliation(s)
- Fang Nie
- Department of Laboratory Medicine, First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, PR China
| | - Dongming Wu
- Department of Laboratory Medicine, First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, PR China
| | - Hongfei Du
- Department of Laboratory Medicine, First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, PR China
| | - Xianggui Yang
- Department of Laboratory Medicine, First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, PR China
| | - Min Yang
- Department of Laboratory Medicine, First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, PR China
| | - Xueli Pang
- Department of Laboratory Medicine, First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, PR China
| | - Ying Xu
- Department of Laboratory Medicine, First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, PR China.
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Mazzotta C, Manetti M, Rosa I, Romano E, Blagojevic J, Bellando-Randone S, Bruni C, Lepri G, Guiducci S, Ibba-Manneschi L, Matucci-Cerinic M. Proangiogenic effects of soluble α-Klotho on systemic sclerosis dermal microvascular endothelial cells. Arthritis Res Ther 2017; 19:27. [PMID: 28183357 PMCID: PMC5301388 DOI: 10.1186/s13075-017-1233-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 01/12/2017] [Indexed: 01/07/2023] Open
Abstract
Background Systemic sclerosis (SSc) is characterized by endothelial cell (EC) apoptosis, impaired angiogenesis and peripheral microvasculopathy. Soluble α-Klotho (sKl) is a pleiotropic molecule with multiple effects on ECs, including antioxidant and vasculoprotective activities. On the EC surface, sKl interacts with vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2) and transient receptor potential canonical-1 (TRPC-1) cation channel to control EC homeostasis. Here, we investigated whether sKl might act as a protective factor to improve angiogenesis in dermal microvascular endothelial cells (MVECs) from SSc patients (SSc-MVECs). Methods Wound healing assay was performed on healthy dermal MVECs (H-MVECs) challenged with sera from healthy controls or SSc patients with or without the addition of sKl. Capillary morphogenesis on Matrigel was assessed in H-MVECs and SSc-MVECs at basal conditions and treated with sKl, as well as in H-MVECs challenged with healthy or SSc sera in presence or absence of sKl. The expression of α-Klotho, VEGF165b, VEGFR-2, TRPC-1, Ki67 and active caspase-3 in H-MVECs and SSc-MVECs was investigated by western blotting. Immunostaining for α-Klotho was performed in H-MVECs and SSc-MVECs, and in healthy and SSc skin sections. Results Treatment with sKl effectively counteracted the inihibitory effects of SSc sera on wound healing ability and angiogenic performance of H-MVECs. The addition of sKl significantly improved angiogenesis and maintained over time capillary-like tube formation in vitro by SSc-MVECs. Stimulation of SSc-MVECs with sKl resulted in the upregulation of the proliferation marker Ki67 in parallel with the downregulation of proapoptotic active caspase-3. The expression of α-Klotho was significantly lower in SSc-MVECs than in H-MVECs. The expression of TRPC-1 was also significantly decreased, while that of VEGFR-2 and VEGF165b was significantly increased, in SSc-MVECs compared with H-MVECs. Challenge with sKl either significantly increased TRPC-1 or decreased VEGF165b in SSc-MVECs. Ex vivo analyses revealed that α-Klotho immunostaining was almost absent in the dermal microvascular network of SSc skin compared with control skin. Conclusions Our findings provide the first evidence that α-Klotho is significantly decreased in the microvasculature in SSc skin and that sKl administration may effectively improve SSc-MVEC functions in vitro by acting as a powerful proangiogenic factor.
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Affiliation(s)
- Celestina Mazzotta
- Department of Experimental and Clinical Medicine, Division of Rheumatology, University of Florence, AOUC, Largo Brambilla 3, 50134, Florence, Italy.
| | - Mirko Manetti
- Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - Irene Rosa
- Department of Experimental and Clinical Medicine, Division of Rheumatology, University of Florence, AOUC, Largo Brambilla 3, 50134, Florence, Italy.,Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - Eloisa Romano
- Department of Experimental and Clinical Medicine, Division of Rheumatology, University of Florence, AOUC, Largo Brambilla 3, 50134, Florence, Italy
| | - Jelena Blagojevic
- Department of Experimental and Clinical Medicine, Division of Rheumatology, University of Florence, AOUC, Largo Brambilla 3, 50134, Florence, Italy
| | - Silvia Bellando-Randone
- Department of Experimental and Clinical Medicine, Division of Rheumatology, University of Florence, AOUC, Largo Brambilla 3, 50134, Florence, Italy
| | - Cosimo Bruni
- Department of Experimental and Clinical Medicine, Division of Rheumatology, University of Florence, AOUC, Largo Brambilla 3, 50134, Florence, Italy
| | - Gemma Lepri
- Department of Experimental and Clinical Medicine, Division of Rheumatology, University of Florence, AOUC, Largo Brambilla 3, 50134, Florence, Italy
| | - Serena Guiducci
- Department of Experimental and Clinical Medicine, Division of Rheumatology, University of Florence, AOUC, Largo Brambilla 3, 50134, Florence, Italy
| | - Lidia Ibba-Manneschi
- Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - Marco Matucci-Cerinic
- Department of Experimental and Clinical Medicine, Division of Rheumatology, University of Florence, AOUC, Largo Brambilla 3, 50134, Florence, Italy
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Hu MC, Shi M, Gillings N, Flores B, Takahashi M, Kuro-O M, Moe OW. Recombinant α-Klotho may be prophylactic and therapeutic for acute to chronic kidney disease progression and uremic cardiomyopathy. Kidney Int 2017; 91:1104-1114. [PMID: 28131398 DOI: 10.1016/j.kint.2016.10.034] [Citation(s) in RCA: 172] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/05/2016] [Accepted: 10/20/2016] [Indexed: 12/24/2022]
Abstract
α-Klotho is highly expressed in the kidney, and its extracellular domain is cleaved and released into the circulation. Chronic kidney disease (CKD) is a state of α-Klotho deficiency, which exerts multiple negative systemic effects on numerous organs including the cardiovascular system. Since acute kidney injury (AKI) greatly escalates the risk of CKD development, we explored the effect of α-Klotho on prevention and treatment on post-AKI to CKD progression and cardiovascular disease. Therein, ischemia reperfusion injury-induced AKI was followed by early administration of recombinant α-Klotho or vehicle starting one day and continued for four days after kidney injury (CKD prevention protocol). A CKD model was generated by unilateral nephrectomy plus contralateral ischemia reperfusion injury. Late administration of α-Klotho in this model was started four weeks after injury and sustained for 12 weeks (CKD treatment protocol). The prevention protocol precluded AKI to CKD progression and protected the heart from cardiac remodeling in the post-AKI model. One important effect of exogenous α-Klotho therapy was the restoration of endogenous α-Klotho levels long after the cessation of exogenous α-Klotho therapy. The treatment protocol still effectively improved renal function and attenuated cardiac remodeling in CKD, although these parameters did not completely return to normal. In addition, α-Klotho administration also attenuated high phosphate diet-induced renal and cardiac fibrosis, and improved renal and cardiac function in the absence of pre-existing renal disease. Thus, recombinant α-Klotho protein is safe and efficacious, and might be a promising prophylactic or therapeutic option for prevention or retardation of AKI-to-CKD progression and uremic cardiomyopathy.
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Affiliation(s)
- Ming Chang Hu
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
| | - Mingjun Shi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Nancy Gillings
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Brianna Flores
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Masaya Takahashi
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Makoto Kuro-O
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Orson W Moe
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
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59
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Drüeke TB, Massy ZA. Changing bone patterns with progression of chronic kidney disease. Kidney Int 2017; 89:289-302. [PMID: 26806832 DOI: 10.1016/j.kint.2015.12.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/04/2015] [Accepted: 09/16/2015] [Indexed: 01/01/2023]
Abstract
It is commonly held that osteitis fibrosa and mixed uremic osteodystrophy are the predominant forms of renal osteodystrophy in patients with chronic kidney disease. Osteitis fibrosa is a high-turnover bone disease resulting mainly from secondary hyperparathyroidism, and mixed uremic osteodystrophy is in addition characterized by a mineralization defect most often attributed to vitamin D deficiency. However, there is ancient and more recent evidence that in early chronic kidney disease stages adynamic bone disease characterized by low bone turnover occurs first, at least in a significant proportion of patients. This could be due to the initial predominance of bone turnover-inhibitory conditions such as resistance to the action of parathyroid hormone (PTH), reduced calcitriol levels, sex hormone deficiency, diabetes, and, last but not least, uremic toxins leading to repression of osteocyte Wnt/β-catenin signaling and increased expression of Wnt antagonists such as sclerostin, Dickkopf-1, and sFRP4. The development of high-turnover bone disease would occur only later on, when serum PTH levels are able to overcome peripheral PTH resistance and the other inhibitory factors of bone formation. Whether FGF23 and Klotho play a direct role in the transition from low- to high-turnover bone disease or participate only indirectly via regulating PTH secretion remains to be seen.
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Affiliation(s)
- Tilman B Drüeke
- Institut National de la Santé et de la Recherche Médicale (Inserm) Unité 1018, Centre de recherche en épidémiologie et santé des populations, Equipe 5, Villejuif; Paris-Sud University and University of Paris-Ouest, Versailles-Saint-Quentin-en-Yvelines; Paris, France.
| | - Ziad A Massy
- Institut National de la Santé et de la Recherche Médicale (Inserm) Unité 1018, Centre de recherche en épidémiologie et santé des populations, Equipe 5, Villejuif; Paris-Sud University and University of Paris-Ouest, Versailles-Saint-Quentin-en-Yvelines; Paris, France; Division of Nephrology, Ambroise Paré Hospital, Assistance Publique Hôpitaux de Paris, Boulogne-Billancourt/Paris; University of Paris-Ouest, Versailles-Saint-Quentin-en-Yvelines; Paris, France
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Mosa O, Skitek M, Jerin A. Validity of Klotho, CYR61 and YKL-40 as ideal predictive biomarkers for acute kidney injury: review study. SAO PAULO MED J 2017; 135:57-65. [PMID: 27759760 PMCID: PMC9969721 DOI: 10.1590/1516-3180.2016.0099220516] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 05/22/2016] [Indexed: 02/08/2023] Open
Abstract
CONTEXT AND OBJECTIVE: Acute kidney injury (AKI) is still a headache for clinicians and scientists as a possible reason for increased death among intensive care unit (ICU) patients after invasive cardiac surgery. Furthermore, the diagnostic process for AKI using conventional biomarkers is not sufficient to ensure early warning of this condition because of the morbid influence of non-renal factors that definitively delay the time for the prognosis. These imposed limitations have led to significant amounts of research targeted towards identifying novel biomarkers for AKI with a sustained degree of sensitivity and specificity. Here, we reviewed previous studies conducted on the Klotho, CYR61 and YKL-40 biomarkers in relation to AKI. DESIGN AND SETTING: Review of the literature conducted in the Institute of Clinical Chemistry & Biochemistry, Ljubljana University Medical Center, Slovenia. METHODS: The literature was searched in PubMed and the Cochrane Library. From the database of this specialty, we selected 17 references that matched our context for detailed analysis and further investigation. RESULTS: The studies reviewed showed notable differences in their results relating to the diagnostic impact of Klotho, CYR61 and YKL-40 on early prediction of AKI. CONCLUSIONS: The results regarding the Klotho, CYR61 and YKL-40 biomarkers showed markedly equivocal performance in the previous studies and did not fulfill the expectations that these factors would form valid possible biomarkers for AKI.
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Affiliation(s)
- Osama Mosa
- PhD. Lecturer of Clinical Biochemistry, Department of Public Health, Health Science College at Al-Leith, Umm Al-Qura University, Saudi Arabia.
| | - Milan Skitek
- PhD. Professor and Head of Institute of Clinical Chemistry and Biochemistry, Ljubljana University Medical Center, Ljubljana, Slovenia.
| | - Ales Jerin
- PhD. Associate Professor and Head of Department of Hormones and Tumor Markers, Institute of Clinical Chemistry and Biochemistry, Ljubljana University Medical Center, Ljubljana, Slovenia.
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Thorsen IS, Bleskestad IH, Jonsson G, Skadberg Ø, Gøransson LG. Neutrophil Gelatinase-Associated Lipocalin, Fibroblast Growth Factor 23, and Soluble Klotho in Long-Term Kidney Donors. NEPHRON EXTRA 2016; 6:31-39. [PMID: 27920796 PMCID: PMC5122995 DOI: 10.1159/000450621] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Background The best treatment for end-stage renal disease (ESRD) is kidney transplantation. Twenty-seven percent of transplantations in Norway are from living donors. Recent studies have shown an increased risk of ESRD and increased mortality in donors. The aim of this study was to determine if the levels of the new biomarkers neutrophil gelatinase-associated lipocalin (NGAL), soluble Klotho (sKlotho), and fibroblast growth factor 23 (FGF23) are changed in kidney donors with normal kidney function defined as an estimated glomerular filtration rate (eGFR) >60 ml/min/1.73 m2 compared to patients with chronic kidney disease (CKD) stages 3-5 and healthy controls. Methods This is a cross-sectional, observational, single-center study including 35 kidney donors with an eGFR ≥60 ml/min/1.73 m2 5 years after donation, 22 patients with CKD stage 3 (eGFR 30-59 ml/min/1.73 m2), 18 patients with CKD stage 4 (eGFR 15-29 ml/min/1.73 m2), 20 patients with CKD stage 5 (eGFR <15 ml/min/1.73 m2), and 35 controls comparing levels of biomarkers in long-term kidney donors with those in CKD patients and healthy controls. Results The level of log NGAL was significantly higher in donors than in healthy controls (2.02 ± 0.10 vs. 1.89 ± 0.10 ng/ml; p < 0.001), and the level increased with declining kidney function. The log FGF23 level was nonsignificantly higher in donors than in controls, but it significantly increased with declining kidney function. The log sKlotho levels were significantly lower in patients with CKD stages 4 and 5 than in controls, but no difference was revealed between controls and donors. Conclusion Kidney donors have significantly higher levels of NGAL than healthy controls after a median of 15 years (range 5-38). NGAL could be a valuable diagnostic marker in the future. FGF23 and sKlotho were not significantly different between donors and controls.
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Affiliation(s)
- Inga Strand Thorsen
- Department of Internal Medicine, Stavanger University Hospital, Stavanger, Norway
| | | | - Grete Jonsson
- Department of Medical Biochemistry, Stavanger University Hospital, Stavanger, Norway
| | - Øyvind Skadberg
- Department of Medical Biochemistry, Stavanger University Hospital, Stavanger, Norway
| | - Lasse Gunnar Gøransson
- Department of Internal Medicine, Stavanger University Hospital, Stavanger, Norway; Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway
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González-Parra E, Aceña Á, Lorenzo Ó, Tarín N, González-Casaus ML, Cristóbal C, Huelmos A, Mahíllo-Fernández I, Pello AM, Carda R, Hernández-González I, Alonso J, Rodríguez-Artalejo F, López-Bescós L, Ortiz A, Egido J, Tuñón J. Important abnormalities of bone mineral metabolism are present in patients with coronary artery disease with a mild decrease of the estimated glomerular filtration rate. J Bone Miner Metab 2016; 34:587-98. [PMID: 26298279 DOI: 10.1007/s00774-015-0706-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 07/16/2015] [Indexed: 11/29/2022]
Abstract
Chronic kidney disease (CKD)-mineral and bone disorder (MBD) is characterized by increased circulating levels of parathormone (PTH) and fibroblast growth factor 23 (FGF23), bone disease, and vascular calcification, and is associated with adverse outcomes. We studied the prevalence of mineral metabolism disorders, and the potential relationship between decreased estimated glomerular filtration rate (eGFR) and CKD-MBD in coronary artery disease patients in a cross-sectional study of 704 outpatients 7.5 ± 3.0 months after an acute coronary syndrome. The mean eGFR (CKD Epidemiology Collaboration formula) was 75.8 ± 19.1 ml/min/1.73 m(2). Our patients showed lower calcidiol plasma levels than a healthy cohort from the same geographical area. In the case of men, this finding was present despite similar creatinine levels in both groups and older age of the healthy subjects. Most patients (75.6 %) had an eGFR below 90 ml/min/1.73 m(2) (eGFR categories G2-G5), with 55.3 % of patients exhibiting values of 60-89 ml/min/1.73 m(2) (G2). PTH (r = -0.3329, p < 0.0001) and FGF23 (r = -0.3641, p < 0.0001) levels inversely correlated with eGFR, whereas calcidiol levels and serum phosphate levels did not. Overall, PTH levels were above normal in 34.9 % of patients. This proportion increased from 19.4 % in G1 category patients, to 33.7 % in G2 category patients and 56.6 % in G3-G5 category patients (p < 0.001). In multivariate analysis, eGFR and calcidiol levels were the main independent determinants of serum PTH. The mean FGF23 levels were 69.9 (54.6-96.2) relative units (RU)/ml, and 33.2 % of patients had FGF23 levels above 85.5 RU/ml (18.4 % in G1 category patients, 30.0 % in G2 category patients, and 59.2 % in G3-G5 category patients; p < 0.001). In multivariate analysis, eGFR was the main predictor of FGF23 levels. Increased phosphate levels were present in 0.7 % of the whole sample: 0 % in G1 category patients, 0.3 % in G2 category patients, and 2.8 % in G3-G5 category patients (p = 0.011). Almost 90 % of patients had calcidiol insufficiency without significant differences among the different degrees of eGFR. In conclusion, in patients with coronary artery disease there is a large prevalence of increased FGF23 and PTH levels. These findings have an independent relationship with decreased eGFR, and are evident at an eGFR of 60-89 ml/min/1.73 m(2). Then, mild decreases in eGFR must be taken in consideration by the clinician because they are associated with progressive abnormalities of mineral metabolism.
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Affiliation(s)
- Emilio González-Parra
- Division of Nephrology and Hypertension, IIS-Fundación Jiménez Díaz and Autónoma University, Madrid, Spain
| | - Álvaro Aceña
- Department of Cardiology, IIS-Fundación Jiménez Díaz, Madrid, Spain
| | - Óscar Lorenzo
- Renal and Vascular Research Laboratory, IIS-Fundación Jiménez Díaz and Autónoma University, Madrid, Spain
| | - Nieves Tarín
- Department of Cardiology, Hospital Universitario de Móstoles, Madrid, Spain
| | | | - Carmen Cristóbal
- Department of Cardiology, Hospital de Fuenlabrada and Rey Juan Carlos University, Fuenlabrada, Spain
| | - Ana Huelmos
- Department of Cardiology, Hospital Universitario Fundación Alcorcón, Madrid, Spain
| | | | - Ana María Pello
- Department of Cardiology, IIS-Fundación Jiménez Díaz, Madrid, Spain
| | - Rocío Carda
- Department of Cardiology, IIS-Fundación Jiménez Díaz, Madrid, Spain
| | | | - Joaquín Alonso
- Department of Cardiology, Hospital de Fuenlabrada and Rey Juan Carlos University, Fuenlabrada, Spain
| | - Fernando Rodríguez-Artalejo
- Department of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Alberto Ortiz
- Division of Nephrology and Hypertension, IIS-Fundación Jiménez Díaz and Autónoma University, Madrid, Spain
| | - Jesús Egido
- Division of Nephrology and Hypertension, IIS-Fundación Jiménez Díaz and Autónoma University, Madrid, Spain
- Renal, Vascular and Diabetes Research Laboratory, IIS-Fundación Jiménez Díaz, Autónoma University, and CIBERDEM, Madrid, Spain
| | - José Tuñón
- Department of Cardiology and Laboratory of Vascular Pathology, IIS-Fundación Jiménez Díaz and Autónoma University, 28040, Madrid, Spain.
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Shi M, Flores B, Gillings N, Bian A, Cho HJ, Yan S, Liu Y, Levine B, Moe OW, Hu MC. αKlotho Mitigates Progression of AKI to CKD through Activation of Autophagy. J Am Soc Nephrol 2016; 27:2331-45. [PMID: 26701976 PMCID: PMC4978045 DOI: 10.1681/asn.2015060613] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 11/01/2015] [Indexed: 12/15/2022] Open
Abstract
AKI confers increased risk of progression to CKD. αKlotho is a cytoprotective protein, the expression of which is reduced in AKI, but the relationship of αKlotho expression level to AKI progression to CKD has not been studied. We altered systemic αKlotho levels by genetic manipulation, phosphate loading, or aging and examined the effect on long-term outcome after AKI in two models: bilateral ischemia-reperfusion injury and unilateral nephrectomy plus contralateral ischemia-reperfusion injury. Despite apparent initial complete recovery of renal function, both types of AKI eventually progressed to CKD, with decreased creatinine clearance, hyperphosphatemia, and renal fibrosis. Compared with wild-type mice, heterozygous αKlotho-hypomorphic mice (αKlotho haploinsufficiency) progressed to CKD much faster, whereas αKlotho-overexpressing mice had better preserved renal function after AKI. High phosphate diet exacerbated αKlotho deficiency after AKI, dramatically increased renal fibrosis, and accelerated CKD progression. Recombinant αKlotho administration after AKI accelerated renal recovery and reduced renal fibrosis. Compared with wild-type conditions, αKlotho deficiency and overexpression are associated with lower and higher autophagic flux in the kidney, respectively. Upregulation of autophagy protected kidney cells in culture from oxidative stress and reduced collagen 1 accumulation. We propose that αKlotho upregulates autophagy, attenuates ischemic injury, mitigates renal fibrosis, and retards AKI progression to CKD.
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Affiliation(s)
- Mingjun Shi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Brianna Flores
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Nancy Gillings
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Ao Bian
- 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
| | | | - Yang Liu
- Internal Medicine, Center for Autophagy Research, and
| | - Beth Levine
- Internal Medicine, Center for Autophagy Research, and Microbiology, and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Orson W Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Internal Medicine, Physiology,
| | - Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Internal Medicine,
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64
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Sharaf El Din UAA, Salem MM, Abdulazim DO. Stop chronic kidney disease progression: Time is approaching. World J Nephrol 2016; 5:258-273. [PMID: 27152262 PMCID: PMC4848149 DOI: 10.5527/wjn.v5.i3.258] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 01/26/2016] [Accepted: 02/24/2016] [Indexed: 02/06/2023] Open
Abstract
Progression of chronic kidney disease (CKD) is inevitable. However, the last decade has witnessed tremendous achievements in this field. Today we are optimistic; the dream of withholding this progression is about to be realistic. The recent discoveries in the field of CKD management involved most of the individual diseases leading the patients to end-stage renal disease. Most of these advances involved patients suffering diabetic kidney disease, chronic glomerulonephritis, polycystic kidney disease, renal amyloidosis and chronic tubulointerstitial disease. The chronic systemic inflammatory status and increased oxidative stress were also investigated. This inflammatory status influences the anti-senescence Klotho gene expression. The role of Klotho in CKD progression together with its therapeutic value are explored. The role of gut as a major source of inflammation, the pathogenesis of intestinal mucosal barrier damage, the role of intestinal alkaline phosphatase and the dietary and therapeutic implications add a novel therapeutic tool to delay CKD progression.
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65
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Almroth G, Lönn J, Uhlin F, Brudin L, Andersson B, Hahn-Zoric M. Sclerostin, TNF-alpha and Interleukin-18 Correlate and are Together with Klotho Related to Other Growth Factors and Cytokines in Haemodialysis Patients. Scand J Immunol 2016; 83:58-63. [PMID: 26448366 DOI: 10.1111/sji.12392] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 09/28/2015] [Indexed: 12/14/2022]
Abstract
Patients with chronic renal failure are known to have renal osteodystrophy (bone disease) and increased calcification of vessels. A new marker of bone disease, sclerostin, the two pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin-18 (IL-18), and the fibroblast growth factor-23 (FGF-23) receptor-associated marker Klotho were tested in 84 haemodialysis (HD) patients and in healthy controls. The patients had significantly higher levels of the three former markers than of the controls while Klotho was significantly higher in the controls. Low level, but significant, correlations were observed in the patient group when the levels of these four markers were compared to each other and to those of 5 cytokines and growth factors tested earlier; high-sensitive CRP (hsCRP), interleukin-6 (IL-6), hepatocyte growth factor (HGF), fibroblast growth factor-23 (FGF-23) and soluble urokinase plasminogen activator (suPAR). Ln sclerostin correlated positively to Ln hsTNF-alpha, Ln HGF and Ln suPAR. Ln hsTNF-alpha correlated positively to Ln sclerostin, Ln hsCRP, Ln IL-6, Ln FGF-23, Ln suPAR and Ln IL-18. Ln IL-18 correlated positively to Ln suPAR and Ln TNF-alpha. Ln Klotho correlated negatively to Ln hsCRP but did not correlate to Ln FGF-23. The markers studied here may be involved in the calcification of vessels seen in HD patients due to a combination of inflammation and bone disease. The mechanisms are still not fully known but may be of importance for future therapeutic possibilities in this group of patients.
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Affiliation(s)
- G Almroth
- Department of Nephrology, Institution of medicine and health sciences, Linköping University, Linköping, Sweden
| | - J Lönn
- Division of Clinical Medicine, School of Health and Medical Sciences, Örebro University, Örebro, Sweden
| | - F Uhlin
- Department of Nephrology, Institution of medicine and health sciences, Linköping University, Linköping, Sweden
| | - L Brudin
- Department of Medicine and Health Sciences, Linköping University, Linköping, Sweden.,Department of Physiology, County Hospital, Kalmar, Sweden
| | - B Andersson
- Department of Clinical Immunology, Sahlgrenska University Hospital, Göteborg, Sweden
| | - M Hahn-Zoric
- Department of Clinical Immunology, Sahlgrenska University Hospital, Göteborg, Sweden
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66
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Salanova Villanueva L, Sánchez González C, Sánchez Tomero JA, Aguilera A, Ortega Junco E. Bone mineral disorder in chronic kidney disease: Klotho and FGF23; cardiovascular implications. Nefrologia 2016; 36:368-75. [PMID: 27118192 DOI: 10.1016/j.nefro.2016.01.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 12/17/2015] [Accepted: 01/02/2016] [Indexed: 12/30/2022] Open
Abstract
Cardiovascular factors are one of the main causes of morbidity and mortality in patients with chronic kidney disease. Bone mineral metabolism disorders and inflammation are pathological conditions that involve increased cardiovascular risk in chronic kidney disease. The cardiovascular risk involvement of bone mineral metabolism classical biochemical parameters such as phosphorus, calcium, vitamin D and PTH is well known. The newest markers, FGF23 and klotho, could also be implicated in cardiovascular disease.
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67
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Buendía P, Ramírez R, Aljama P, Carracedo J. Klotho Prevents Translocation of NFκB. VITAMINS AND HORMONES 2016; 101:119-50. [PMID: 27125740 DOI: 10.1016/bs.vh.2016.02.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Klotho protein is a β-glucuronidase capable of hydrolyzing steroid β-glucuronides. Two molecules are produced by the Klotho gene, a membrane bound form and a circulating form. This protein is recognized as an antiaging gene with pleiotropic functions. The activation of cellular systems is associated with the pathogenesis of several chronic and degenerative diseases associated with an inflammatory state. Inflammation is characterized by an activation of NFκB. Klotho suppresses nuclear factor NFκB activation and the subsequent transcription of proinflammatory genes. This review focuses on the current understanding of Klotho protein function and its relationship with NFκB regulation, emphasizing its potential involvement in the pathophysiologic process.
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Affiliation(s)
- P Buendía
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Universidad de Córdoba/Hospital Universitario Reina Sofía, Córdoba, Spain
| | - R Ramírez
- Alcalá de Henares University, Madrid, Spain
| | - P Aljama
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Universidad de Córdoba/Hospital Universitario Reina Sofía, Córdoba, Spain
| | - J Carracedo
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Universidad de Córdoba/Hospital Universitario Reina Sofía, Córdoba, Spain.
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68
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Donate-Correa J, Martín-Núñez E, Mora-Fernández C, Muros-de-Fuentes M, Pérez-Delgado N, Navarro-González JF. Klotho in cardiovascular disease: Current and future perspectives. World J Biol Chem 2015; 6:351-357. [PMID: 26629318 PMCID: PMC4656911 DOI: 10.4331/wjbc.v6.i4.351] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 07/31/2015] [Accepted: 09/08/2015] [Indexed: 02/05/2023] Open
Abstract
Protein Klotho, beyond its role as a regulator of the phosphatemia, is also involved in the maintaining of the cardiovascular health, being associated its alterations with the development of cardiovascular damage and increased morbi-mortality. For all this, nowadays Klotho is the subject of a thorough research which is focused on uncover its intimate mechanisms of action, and in analyzing the utility of its modulation as a potential strategy with clinical applicability. Molecular mechanisms of Klotho are not well understood but an emerging research area links Klotho deficiency with vascular pathology. Changes in this protein have been associated with cardiovascular-related complications like inflammation, vascular calcification, and endothelial dysfunction. All this is particularly relevant if considering the recent discovery of Klotho expression in vascular tissue.
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69
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Pulskens WP, Verkaik M, Sheedfar F, van Loon EP, van de Sluis B, Vervloet MG, Hoenderop JG, Bindels RJ. Deregulated Renal Calcium and Phosphate Transport during Experimental Kidney Failure. PLoS One 2015; 10:e0142510. [PMID: 26566277 PMCID: PMC4643984 DOI: 10.1371/journal.pone.0142510] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 10/22/2015] [Indexed: 12/17/2022] Open
Abstract
Impaired mineral homeostasis and inflammation are hallmarks of chronic kidney disease (CKD), yet the underlying mechanisms of electrolyte regulation during CKD are still unclear. Here, we applied two different murine models, partial nephrectomy and adenine-enriched dietary intervention, to induce kidney failure and to investigate the subsequent impact on systemic and local renal factors involved in Ca(2+) and Pi regulation. Our results demonstrated that both experimental models induce features of CKD, as reflected by uremia, and elevated renal neutrophil gelatinase-associated lipocalin (NGAL) expression. In our model kidney failure was associated with polyuria, hypercalcemia and elevated urinary Ca(2+) excretion. In accordance, CKD augmented systemic PTH and affected the FGF23-αklotho-vitamin-D axis by elevating circulatory FGF23 levels and reducing renal αklotho expression. Interestingly, renal FGF23 expression was also induced by inflammatory stimuli directly. Renal expression of Cyp27b1, but not Cyp24a1, and blood levels of 1,25-dihydroxy vitamin D3 were significantly elevated in both models. Furthermore, kidney failure was characterized by enhanced renal expression of the transient receptor potential cation channel subfamily V member 5 (TRPV5), calbindin-D28k, and sodium-dependent Pi transporter type 2b (NaPi2b), whereas the renal expression of sodium-dependent Pi transporter type 2a (NaPi2a) and type 3 (PIT2) were reduced. Together, our data indicates two different models of experimental kidney failure comparably associate with disturbed FGF23-αklotho-vitamin-D signalling and a deregulated electrolyte homeostasis. Moreover, this study identifies local tubular, possibly inflammation- or PTH- and/or FGF23-associated, adaptive mechanisms, impacting on Ca(2+)/Pi homeostasis, hence enabling new opportunities to target electrolyte disturbances that emerge as a consequence of CKD development.
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Affiliation(s)
- Wilco P. Pulskens
- Dept. of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
- Dept. of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Melissa Verkaik
- Dept. of Nephrology, VU University Medical Center, Amsterdam, The Netherlands
| | - Fareeba Sheedfar
- Dept. of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ellen P. van Loon
- Dept. of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bart van de Sluis
- Dept. of Pediatrics, Molecular Genetics Section, University Medical Center Groningen, Groningen, The Netherlands
| | - Mark G. Vervloet
- Dept. of Nephrology, VU University Medical Center, Amsterdam, The Netherlands
| | - Joost G. Hoenderop
- Dept. of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René J. Bindels
- Dept. of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
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Zhou X, Chen K, Wang Y, Schuman M, Lei H, Sun Z. Antiaging Gene Klotho Regulates Adrenal CYP11B2 Expression and Aldosterone Synthesis. J Am Soc Nephrol 2015; 27:1765-76. [PMID: 26471128 DOI: 10.1681/asn.2015010093] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 08/27/2015] [Indexed: 12/11/2022] Open
Abstract
Deficiency of the antiaging gene Klotho (KL) induces renal damage and hypertension through unknown mechanisms. In this study, we assessed whether KL regulates expression of CYP11B2, a key rate-limiting enzyme in aldosterone synthesis, in adrenal glands. We found that haplodeficiency of KL(+/-) in mice increased the plasma level of aldosterone by 16 weeks of age, which coincided with spontaneous and persistent elevation of BP. Blockade of aldosterone actions by eplerenone reversed KL deficiency-induced hypertension and attenuated the kidney damage. Protein expression of CYP11B2 was upregulated in adrenal cortex of KL(+/-) mice. KL and CYP11B2 proteins colocalized in adrenal zona glomerulosa cells. Silencing of KL upregulated and overexpression of KL downregulated CYP11B2 expression in human adrenocortical cells. Notably, silencing of KL decreased expression of SF-1, a negative transcription factor of CYP11B2, but increased phosphorylation of ATF2, a positive transcription factor of CYP11B2, which may contribute to upregulation of CYP11B2 expression. Therefore, these results show that KL regulates adrenal CYP11B2 expression. KL deficiency-induced spontaneous hypertension and kidney damage may be partially attributed to the upregulation of CYP11B2 expression and aldosterone synthesis.
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Affiliation(s)
- Xiaoli Zhou
- Department of Cardiology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China; and Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Kai Chen
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Yongjun Wang
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Mariano Schuman
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Han Lei
- Department of Cardiology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China; and
| | - Zhongjie Sun
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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Ni W, Fang Y, Xie L, Liu X, Shan W, Zeng R, Liu J, Liu X. Adipose-Derived Mesenchymal Stem Cells Transplantation Alleviates Renal Injury in Streptozotocin-Induced Diabetic Nephropathy. J Histochem Cytochem 2015. [PMID: 26215800 DOI: 10.1369/0022155415599039] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Previous studies have illustrated that bone marrow-derived mesenchymal stem cell (BMMSC) transplantation has therapeutic effects on diabetes and can prevent mice from renal damage and diabetic nephropathy (DN). Moreover, adipose-derived MSCs possess similar characteristics to BMMSCs. We investigated the effect of ADMSC transplantation on streptozotocin (STZ)-induced renal injury. Diabetes was induced in rats by STZ injection. After ADMSC treatment, renal histological changes and cell apoptosis were evaluated as were the expression of apoptosis-related proteins, Wnt/β-catenin pathway members, and klotho levels. We found that ADMSCs improved renal histological changes. Next, NRK-52E cells were exposed to normal glucose (NG; 5.5 mM glucose plus 24.5 mM mannitol)/high glucose (HG) or ADMSCs, and then measured for changes in the aforementioned proteins. Similarly, changes in these proteins were also determined following transient transfection of klotho siRNA. We found that both ADMSC transplantation and co-incubation reduced the rate of cellular apoptosis, decreased Bax and Wnt/β-catenin levels, and elevated Bcl-2 and klotho levels. Interestingly, klotho knockdown reversed the effects of ADMSCs on the expression of apoptosis-related proteins and Wnt/β-catenin pathway members. Taken together, ADMSCs transplantation might attenuate renal injury in DN via activating klotho and inhibiting the Wnt/β-catenin pathway. This study may provide evidence for the treatment of DN using ADMSCs.
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Affiliation(s)
- Weimin Ni
- Department of Anatomy, College of Basic Medical Sciences, Liaoning Medical University, Jinzhou, Liaoning, People's Republic of China (WN, YF, LX, XL, WS, RZ, JL, XL),Department of Neurosurgery, The First Affiliated Hospital of Liaoning Medical University, Jinzhou, Liaoning, People's Republic of China (WN)
| | - Yan Fang
- Department of Anatomy, College of Basic Medical Sciences, Liaoning Medical University, Jinzhou, Liaoning, People's Republic of China (WN, YF, LX, XL, WS, RZ, JL, XL)
| | - Ling Xie
- Department of Anatomy, College of Basic Medical Sciences, Liaoning Medical University, Jinzhou, Liaoning, People's Republic of China (WN, YF, LX, XL, WS, RZ, JL, XL)
| | - Xue Liu
- Department of Anatomy, College of Basic Medical Sciences, Liaoning Medical University, Jinzhou, Liaoning, People's Republic of China (WN, YF, LX, XL, WS, RZ, JL, XL)
| | - Wei Shan
- Department of Anatomy, College of Basic Medical Sciences, Liaoning Medical University, Jinzhou, Liaoning, People's Republic of China (WN, YF, LX, XL, WS, RZ, JL, XL)
| | - Ruixia Zeng
- Department of Anatomy, College of Basic Medical Sciences, Liaoning Medical University, Jinzhou, Liaoning, People's Republic of China (WN, YF, LX, XL, WS, RZ, JL, XL)
| | - Jiansheng Liu
- Department of Anatomy, College of Basic Medical Sciences, Liaoning Medical University, Jinzhou, Liaoning, People's Republic of China (WN, YF, LX, XL, WS, RZ, JL, XL)
| | - Xueyuan Liu
- Department of Anatomy, College of Basic Medical Sciences, Liaoning Medical University, Jinzhou, Liaoning, People's Republic of China (WN, YF, LX, XL, WS, RZ, JL, XL)
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Xie J, Yoon J, An SW, Kuro-o M, Huang CL. Soluble Klotho Protects against Uremic Cardiomyopathy Independently of Fibroblast Growth Factor 23 and Phosphate. J Am Soc Nephrol 2015; 26:1150-60. [PMID: 25475745 PMCID: PMC4413766 DOI: 10.1681/asn.2014040325] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 07/22/2014] [Indexed: 11/03/2022] Open
Abstract
Cardiac hypertrophy occurs in up to 95% of patients with CKD and increases their risk for cardiovascular death. In the kidney, full-length membranous Klotho forms the coreceptor for fibroblast growth factor 23 (FGF23) to regulate phosphate metabolism. The prevailing view is that the decreased level of Klotho in CKD causes cardiomyopathy through increases in serum FGF23 and/or phosphate levels. However, we reported recently that soluble Klotho protects against cardiac hypertrophy by inhibiting abnormal calcium signaling in the heart. Here, we tested whether this protective effect requires changes in FGF23 and/or phosphate levels. Heterozygous Klotho-deficient CKD mice exhibited aggravated cardiac hypertrophy compared with wild-type CKD mice. Cardiac magnetic resonance imaging studies revealed that Klotho-deficient CKD hearts had worse functional impairment than wild-type CKD hearts. Normalization of serum phosphate and FGF23 levels by dietary phosphate restriction did not abrogate the aggravated cardiac hypertrophy observed in Klotho-deficient CKD mice. Circulating levels of the cleaved soluble ectodomain of Klotho were lower in wild-type CKD mice than in control mice and even lower in Klotho-deficient CKD mice. Intravenous delivery of a transgene encoding soluble Klotho ameliorated cardiac hypertrophy in Klotho-deficient CKD mice. These results suggest that the decreased level of circulating soluble Klotho in CKD is an important cause of uremic cardiomyopathy independent of FGF23 and phosphate, opening new avenues for treatment of this disease.
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Affiliation(s)
- Jian Xie
- Division of Nephrology, Department of Medicine
| | - Joonho Yoon
- Division of Nephrology, Department of Medicine
| | - Sung-Wan An
- Division of Nephrology, Department of Medicine
| | - Makoto Kuro-o
- Department of Pathology, and Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas; and Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Chou-Long Huang
- Division of Nephrology, Department of Medicine, Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas; and
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73
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Yokoyama JS, Sturm VE, Bonham LW, Klein E, Arfanakis K, Yu L, Coppola G, Kramer JH, Bennett DA, Miller BL, Dubal DB. Variation in longevity gene KLOTHO is associated with greater cortical volumes. Ann Clin Transl Neurol 2015; 2:215-30. [PMID: 25815349 PMCID: PMC4369272 DOI: 10.1002/acn3.161] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 11/24/2014] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE Identifying genetic variation associated with brain structures in aging may elucidate new biologic mechanisms underlying resilience to cognitive decline. We investigated whether carrying one copy of the protective haplotype "KL-VS" in longevity gene KLOTHO (KL) is associated with greater gray matter volume in healthy human aging compared to carrying no copies. METHODS We performed unbiased whole-brain analysis in cognitively normal older adults from two independent cohorts to assess the relationship between KL-VS and gray matter volume using voxel-based morphometry. RESULTS We found that KL-VS heterozygosity was associated with greater volume in right dorsolateral prefrontal cortex (rDLPFC). Because rDLPFC is important for executive function, we analyzed working memory and processing speed in individuals. KL-VS heterozygosity was associated with enhanced executive function. Larger rDLPFC volume correlated with better executive function across the lifespan examined. Statistical analysis suggested that volume partially mediates the effect of genotype on cognition. INTERPRETATION These results suggest that variation in KL is associated with bigger brain volume and better function.
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Affiliation(s)
- Jennifer S Yokoyama
- Department of Neurology, University of California San FranciscoSan Francisco, California, 94158
| | - Virginia E Sturm
- Department of Neurology, University of California San FranciscoSan Francisco, California, 94158
| | - Luke W Bonham
- Department of Neurology, University of California San FranciscoSan Francisco, California, 94158
| | - Eric Klein
- Department of Neurology and Semel Institute for Neuroscience and Human Behavior, The David Geffen School of Medicine at University of California Los AngelesLos Angeles, California, 90095
| | - Konstantinos Arfanakis
- Department of Biomedical Engineering, Illinois Institute of TechnologyChicago, Illinois, 60616
- Rush Alzheimer's Disease Center, Rush University Medical CenterChicago, Illinois, 60612
| | - Lei Yu
- Rush Alzheimer's Disease Center, Rush University Medical CenterChicago, Illinois, 60612
| | - Giovanni Coppola
- Department of Neurology and Semel Institute for Neuroscience and Human Behavior, The David Geffen School of Medicine at University of California Los AngelesLos Angeles, California, 90095
| | - Joel H Kramer
- Department of Neurology, University of California San FranciscoSan Francisco, California, 94158
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical CenterChicago, Illinois, 60612
| | - Bruce L Miller
- Department of Neurology, University of California San FranciscoSan Francisco, California, 94158
| | - Dena B Dubal
- Department of Neurology, University of California San FranciscoSan Francisco, California, 94158
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Abstract
PURPOSE OF REVIEW Cardiovascular disease remains the single most serious contributor to mortality in chronic kidney disease (CKD). Although conventional risk factors are prevalent in CKD, both cardiomyopathy and vasculopathy can be caused by pathophysiologic mechanisms specific to the uremic state. CKD is a state of systemic αKlotho deficiency. Although the molecular mechanism of action of αKlotho is not well understood, the downstream targets and biologic functions of αKlotho are astonishingly pleiotropic. An emerging body of literature links αKlotho to uremic vasculopathy. RECENT FINDINGS The expression of αKlotho in the vasculature is controversial because of conflicting data. Regardless of whether αKlotho acts as a circulating or resident protein, there are good data associating changes in αKlotho levels with vascular pathology including vascular calcification and in-vitro data of the direct action of αKlotho on both the endothelium and vascular smooth muscle cells in terms of cytoprotection and prevention of mineralization. SUMMARY It is critical to understand the pathogenic role of αKlotho on the integral endothelium-vascular smooth muscle network rather than each cell type in isolation in uremic vasculopathy, as αKlotho can serve as a potential prognostic biomarker and a biological therapeutic agent.
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75
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Leibrock CB, Alesutan I, Voelkl J, Pakladok T, Michael D, Schleicher E, Kamyabi-Moghaddam Z, Quintanilla-Martinez L, Kuro-o M, Lang F. NH4Cl Treatment Prevents Tissue Calcification in Klotho Deficiency. J Am Soc Nephrol 2015; 26:2423-33. [PMID: 25644113 DOI: 10.1681/asn.2014030230] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 11/30/2014] [Indexed: 11/03/2022] Open
Abstract
Klotho, a cofactor in suppressing 1,25(OH)2D3 formation, is a powerful regulator of mineral metabolism. Klotho-hypomorphic mice (kl/kl) exhibit excessive plasma 1,25(OH)2D3, Ca(2+), and phosphate concentrations, severe tissue calcification, volume depletion with hyperaldosteronism, and early death. Calcification is paralleled by overexpression of osteoinductive transcription factor Runx2/Cbfa1, Alpl, and senescence-associated molecules Tgfb1, Pai-1, p21, and Glb1. Here, we show that NH4Cl treatment in drinking water (0.28 M) prevented soft tissue and vascular calcification and increased the life span of kl/kl mice >12-fold in males and >4-fold in females without significantly affecting extracellular pH or plasma concentrations of 1,25(OH)2D3, Ca(2+), and phosphate. NH4Cl treatment significantly decreased plasma aldosterone and antidiuretic hormone concentrations and reversed the increase of Runx2/Cbfa1, Alpl, Tgfb1, Pai-1, p21, and Glb1 expression in aorta of kl/kl mice. Similarly, in primary human aortic smooth muscle cells (HAoSMCs), NH4Cl treatment reduced phosphate-induced mRNA expression of RUNX2/CBFA1, ALPL, and senescence-associated molecules. In both kl/kl mice and phosphate-treated HAoSMCs, levels of osmosensitive transcription factor NFAT5 and NFAT5-downstream mediator SOX9 were higher than in controls and decreased after NH4Cl treatment. Overexpression of NFAT5 in HAoSMCs mimicked the effect of phosphate and abrogated the effect of NH4Cl on SOX9, RUNX2/CBFA1, and ALPL mRNA expression. TGFB1 treatment of HAoSMCs upregulated NFAT5 expression and prevented the decrease of phosphate-induced NFAT5 expression after NH4Cl treatment. In conclusion, NH4Cl treatment prevents tissue calcification, reduces vascular senescence, and extends survival of klotho-hypomorphic mice. The effects of NH4Cl on vascular osteoinduction involve decrease of TGFB1 and inhibition of NFAT5-dependent osteochondrogenic signaling.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Makoto Kuro-o
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas
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Mishima T, Motoyama K, Imanishi Y, Hamamoto K, Nagata Y, Yamada S, Kuriyama N, Watanabe Y, Emoto M, Inaba M. Decreased cortical thickness, as estimated by a newly developed ultrasound device, as a risk for vertebral fracture in type 2 diabetes mellitus patients with eGFR of less than 60 mL/min/1.73 m2. Osteoporos Int 2015; 26:229-36. [PMID: 25187117 PMCID: PMC4286635 DOI: 10.1007/s00198-014-2843-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 08/05/2014] [Indexed: 01/22/2023]
Abstract
UNLABELLED Cortical porosity is increasingly recognized as an important risk for fracture in DM patients. The present study demonstrated that decreased cortical thickness, assessed using a newly developed quantitative ultrasonic bone densitometry, is a significant risk factor for vertebral fractures in type 2 diabetes mellitus patients with stage 3 or higher chronic kidney disease, but not in those without. INTRODUCTION Cortical porosity is increasingly recognized as an important risk factor for fracture in type 2 diabetes mellitus (T2DM) patients as well as in stage 3 chronic kidney disease (CKD) patients in whom serum parathyroid hormone (PTH) starts to increase. The present study aimed to clarify whether the coexistence of CKD might affect the relationship of decreased cortical thickness (CoTh) in the development of vertebral fractures (VF) in T2DM patients. METHODS In this cross-sectional study, trabecular bone mineral density (TrBMD), elastic modulus of trabecular bone (EMTb), and CoTh were estimated with a new quantitative ultrasound bone densitometry in 173 T2DM patients. VFs were identified radiographically. RESULTS Thirty-nine patients (22.5%) had VF. Those with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2) (low eGFR) showed a significantly higher VF rate (32.4%) than those with eGFR ≥60 mL/min/1.73 m(2) (high eGFR, 16.2%). Serum PTH was significantly higher with low eGFR than with high eGFR. In those with high eGFR, EMTb was significantly lower in VF(+) than VF(-). In those with low eGFR, TrBMD, EMTb, and CoTh were significantly lower in VF(+) than in VF(-). In a multivariate logistic regression analysis, EMTb was independently and significantly associated with VF in T2DM patients with a high eGFR, in contrast to those with only CoTh with VF in T2DM with low eGFR. CONCLUSION This study demonstrated CoTh as a factor independently associated with VF in T2DM patients with low eGFR and increasing serum PTH levels.
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Affiliation(s)
- T. Mishima
- Department of Metabolism, Endocrinology, and Molecular Medicine, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - K. Motoyama
- Department of Metabolism, Endocrinology, and Molecular Medicine, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Y. Imanishi
- Department of Metabolism, Endocrinology, and Molecular Medicine, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - K. Hamamoto
- Department of Metabolism, Endocrinology, and Molecular Medicine, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Y. Nagata
- Department of Metabolism, Endocrinology, and Molecular Medicine, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - S. Yamada
- Department of Metabolism, Endocrinology, and Molecular Medicine, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - N. Kuriyama
- Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Y. Watanabe
- Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - M. Emoto
- Department of Metabolism, Endocrinology, and Molecular Medicine, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - M. Inaba
- Department of Metabolism, Endocrinology, and Molecular Medicine, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
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Feger M, Mia S, Pakladok T, Nicolay JP, Alesutan I, Schneider SW, Voelkl J, Lang F. Down-regulation of renal klotho expression by Shiga toxin 2. Kidney Blood Press Res 2014; 39:441-9. [PMID: 25471359 DOI: 10.1159/000368457] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Shiga toxin 2 may trigger classical hemolytic uremic syndrome (HUS) eventually leading to renal failure. Klotho, a transmembrane protein, protease and hormone mainly expressed in kidney is involved in the regulation of renal phosphate excretion and also retains renal protective effects. Renal failure is associated with renal depletion of klotho. The present study explored the influence of Shiga toxin 2 on renal klotho expression. METHODS Mice were injected with either solvent or Shiga toxin 2 and urinary flow rate and phosphate excretion were determined in metabolic cages. Renal transcript levels were measured by quantitative RT-PCR and renal protein abundance by Western blotting. Plasma concentrations of 1,25(OH)2D3 and FGF23 were determined by ELISA and plasma phosphate and urea concentrations by photometry. RESULTS Shiga toxin 2 treatment was followed by increase of plasma urea concentration, urinary flow rate and renal phosphate excretion but not of plasma phosphate concentration. Shiga toxin 2 treatment strongly decreased klotho mRNA expression and klotho protein abundance in renal tissue. Shiga toxin 2 treatment further increased tumor necrosis factor (Tnfα) mRNA levels, as well as protein abundance of phosphorylated p38 MAPK in renal tissue. The treatment significantly increased renal Cyp27b1 and decreased renal Cyp24a1 mRNA levels without significantly altering plasma 1,25(OH)2D3 levels. Shiga toxin 2 treatment was further followed by increase of plasma FGF23 concentrations. CONCLUSION Shiga toxin 2 treatment stimulated Tnfα transcription, down-regulated renal klotho expression and increased FGF23 formation, effects presumably contributing to renal tissue injury.
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Affiliation(s)
- Martina Feger
- Department of Physiology, University of Tübingen, Tübingen, Germany
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78
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Lang F, Ritz E, Alesutan I, Voelkl J. Impact of aldosterone on osteoinductive signaling and vascular calcification. Nephron Clin Pract 2014; 128:40-5. [PMID: 25377380 DOI: 10.1159/000368268] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Vascular calcification is frequently found already in early stages of chronic kidney disease (CKD) patients and is associated with high cardiovascular risk. The process of vascular calcification is not considered a passive phenomenon but involves, at least in part, phenotypical transformation of vascular smooth muscle cells (VSMCs). Following exposure to excessive extracellular phosphate concentrations, VSMCs undergo a reprogramming into osteo-/chondroblast-like cells. Such 'vascular osteoinduction' is characterized by expression of osteogenic transcription factors and triggered by increased phosphate concentrations. A key role in this process is assigned to cellular phosphate transporters, most notably the type III sodium-dependent phosphate transporter Pit1. Pit1 expression is stimulated by mineralocorticoid receptor activation. Therefore, aldosterone participates in the phenotypical transformation of VSMCs. In preclinical models, aldosterone antagonism reduces vascular osteoinduction. Patients with CKD suffer from hyperphosphatemia predisposing to vascular osteogenic transformation, potentially further fostered by concomitant hyperaldosteronism. Clearly, additional research is required to define the role of aldosterone in the regulation of osteogenic signaling and the consecutive vascular calcification in CKD, but more generally also other diseases associated with excessive vascular calcification and even in individuals without overt disease.
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Affiliation(s)
- Florian Lang
- Department of Physiology, University of Tübingen, Tübingen, Germany
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79
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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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80
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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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81
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Zhou X, Chen K, Lei H, Sun Z. Klotho gene deficiency causes salt-sensitive hypertension via monocyte chemotactic protein-1/CC chemokine receptor 2-mediated inflammation. J Am Soc Nephrol 2014; 26:121-32. [PMID: 24904083 DOI: 10.1681/asn.2013101033] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Klotho (KL) is a newly discovered aging suppressor gene. In mice, the KL gene extends the lifespan when overexpressed and shortens the lifespan when disrupted. This study investigated if KL deficiency affects BP and salt sensitivity using KL mutant heterozygous (+/-) mice and wild-type (WT) mice (9 weeks of age, 16 mice per group). Notably, systolic BP in KL(+/-) mice began to increase at the age of 15 weeks, reached a peak level at the age of 17 weeks, and remained elevated thereafter, whereas systolic BP remained consistent in WT mice. High salt (HS) intake further increased BP in KL(+/-) mice but did not affect BP in WT mice. Blockade of CC chemokine receptor 2 (CCR2), involved in monocyte chemotaxis, by a specific CCR2 antagonist (INCB3284) abolished the HS-induced increase in BP in KL(+/-) mice. Furthermore, HS loading substantially increased the expression of monocyte chemotactic protein-1 and the infiltration of macrophages and T cells in kidneys in KL(+/-) mice, and treatment with INCB3284 abolished these effects. Treatment of KL(+/-) mice with INCB3284 also attenuated the increased renal expressions of serum glucocorticoid-regulated kinase 1, thiazide-sensitive NaCl cotransporter, and ATP synthase β along with the renal structural damage and functional impairment induced by HS loading. In conclusion, KL deficiency caused salt-sensitive hypertension and renal damage by CCR2-mediated inflammation.
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Affiliation(s)
- Xiaoli Zhou
- Department of Cardiology, The First Affiliated Hospital, Chongqing Medical University, Chongqing, China; and Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Kai Chen
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Han Lei
- Department of Cardiology, The First Affiliated Hospital, Chongqing Medical University, Chongqing, China; and
| | - Zhongjie Sun
- Department of Cardiology, The First Affiliated Hospital, Chongqing Medical University, Chongqing, China; and Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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82
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Zununi Vahed S, Nikasa P, Ardalan M. Klotho and renal fibrosis. Nephrourol Mon 2013; 5:946-8. [PMID: 24693499 PMCID: PMC3955284 DOI: 10.5812/numonthly.16179] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 11/11/2013] [Indexed: 02/06/2023] Open
Affiliation(s)
- Sepide Zununi Vahed
- Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, IR Iran
- Chronic Kidney Disease Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran
| | - Parisa Nikasa
- Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, IR Iran
- Chronic Kidney Disease Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran
| | - Mohammadreza Ardalan
- Chronic Kidney Disease Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran
- Corresponding author: Mohammadreza Ardalan, Chronic Kidney Disease Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran. Tel: +98-9141168518, Fax: +98-4113366579, E-mail:
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83
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Gutiérrez OM. The connection between dietary phosphorus, cardiovascular disease, and mortality: where we stand and what we need to know. Adv Nutr 2013; 4:723-9. [PMID: 24228204 PMCID: PMC3823521 DOI: 10.3945/an.113.004812] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Disorders of phosphorus metabolism are independent risk factors for cardiovascular disease. Because excess dietary phosphorus intake is common in the general population and plays a central role in disturbances in phosphorus homeostasis, these findings have fueled interest in restricting phosphorus intake as a potential therapy for improving cardiovascular outcomes. Although experimental and observational data support this possibility, current limitations in the assessment of dietary phosphorus consumption in free-living populations and the lack of reliable biomarkers of the effects of dietary phosphorus on cardiovascular health pose major barriers to the design and conduct of trials assessing the efficacy of phosphorus restriction in improving cardiovascular health. Fibroblast growth factor 23 and Klotho are novel mediators of phosphorus metabolism that are tightly linked to dietary phosphorus intake and show promise as integrated biomarkers of phosphorus excess and its long-term health consequences. Advances in the understanding of how these hormones are associated with diet and phosphorus metabolism will likely bolster future efforts to assess the true health consequences of excess phosphorus intake and whether restricting phosphorus intake has salutary effects on cardiovascular health.
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Lin Y, Kuro-o M, Sun Z. Genetic deficiency of anti-aging gene klotho exacerbates early nephropathy in STZ-induced diabetes in male mice. Endocrinology 2013; 154:3855-63. [PMID: 23928372 PMCID: PMC3776873 DOI: 10.1210/en.2013-1053] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Klotho is a recently discovered anti-aging gene and is primarily expressed in kidneys. In humans, the klotho level decreases with age whereas the prevalence of chronic kidney disease (CKD) increases with age. Diabetic nephropathy is the most common form of CKD, which leads to end-stage renal disease. A decrease in klotho has been found in kidneys of patients with diabetic nephropathy. The purpose of this study is to assess whether klotho gene deficiency affects early diabetic nephropathy in a mouse of model of type 1 diabetes induced by streptozotocin (STZ). Male KL(+/-) mutant and wild-type mice (6-8 weeks) were injected with multiple low doses of STZ. Renal functions and renal blood flow were assessed. Kidneys were collected for histological examination and molecular assays of TGFβ1 and mammalian targets of rapamycin (mTOR) signaling. Klotho deficiency in KL(+/-) mutant mice exacerbated STZ-induced increases in urine albumin, blood urea nitrogen, expansion of mesangial matrix in renal glomeruli, and kidney hypertrophy, suggesting a protective role of klotho in kidney function and structure. Klotho deficiency did not affect renal blood flow. Notably, klotho deficiency significantly increased phosphorylation of Smad2, indicating enhanced TGFβ1 signaling in kidneys. Klotho deficiency also increased phosphorylation of mTOR and S6 (a downstream effector of mTOR), indicating enhanced mTOR signaling in kidneys of early diabetic mice. Thus, klotho gene deficiency may make kidneys more susceptible to diabetic injury. Klotho gene deficiency exacerbated early diabetic nephropathy via enhancing both TGFβ1 and mTOR signaling in kidneys.
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Affiliation(s)
- Yi Lin
- MD, PhD, FAHA, Professor of Physiology, Director, The Robert and Mary Cade Laboratory, BMSB 662A, Box 26901, Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, 940 S. L. Young Boulevard, Oklahoma City, OK 73126-0901.
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Liabeuf S, Okazaki H, Desjardins L, Fliser D, Goldsmith D, Covic A, Wiecek A, Ortiz A, Martinez-Castelao A, Lindholm B, Suleymanlar G, Mallamaci F, Zoccali C, London G, Massy ZA. Vascular calcification in chronic kidney disease: are biomarkers useful for probing the pathobiology and the health risks of this process in the clinical scenario? Nephrol Dial Transplant 2013; 29:1275-84. [DOI: 10.1093/ndt/gft368] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Block GA, Ix JH, Ketteler M, Martin KJ, Thadhani RI, Tonelli M, Wolf M, Jüppner H, Hruska K, Wheeler DC. Phosphate Homeostasis in CKD: Report of a Scientific Symposium Sponsored by the National Kidney Foundation. Am J Kidney Dis 2013; 62:457-73. [DOI: 10.1053/j.ajkd.2013.03.042] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 03/19/2013] [Indexed: 02/08/2023]
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87
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Izquierdo MC, Perez-Gomez MV, Sanchez-Niño MD, Sanz AB, Ruiz-Andres O, Poveda J, Moreno JA, Egido J, Ortiz A. Klotho, phosphate and inflammation/ageing in chronic kidney disease. Nephrol Dial Transplant 2013; 27 Suppl 4:iv6-10. [PMID: 23258814 DOI: 10.1093/ndt/gfs426] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Evidence is emerging for the inflammatory nature of many ageing-associated diseases, including atherosclerosis, vascular calcification, diabetes and chronic kidney disease (CKD), among others. Ageing itself results in chronic low-grade inflammation that promotes end-organ damage. Inflammatory organ damage, in turn, may contribute to inflammation. Recent research has identified the kidney-secreted hormone Klotho as a central player at the ageing-inflammation interface. Thus, systemic or local renal inflammation decreases kidney Klotho expression. Klotho down-regulation may be induced by specific cytokines such as tumour necrosis factor-α or TWEAK through the canonical activation of the inflammatory transcription factor nuclear factor kappa B (NFκB) and, specifically RelA. In addition, inflammatory cytokines lead to the epigenetic inactivation of Klotho transcription. Klotho itself has antioxidant and anti-inflammatory properties and the canonical NFκB component RelA is one of its targets. Klotho is a key regulator of phosphate balance and a role of phosphate in ageing has been shown. However, the potential relationship between phosphate and inflammation requires further clarification. A correct understanding of these interactions may lead to the design of novel therapeutic approaches to CKD and CKD-related inflammatory and ageing features as well as to inflammation/ageing in general.
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Clinical assessment of phosphorus status, balance and renal handling in normal individuals and in patients with chronic kidney disease. Curr Opin Nephrol Hypertens 2013; 22:452-8. [DOI: 10.1097/mnh.0b013e328362483a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Gutiérrez OM, Ix JH. α-Klotho and Kidney Function Decline: An Important Step Forward in Understanding the Link Between Mineral Metabolism and Kidney Disease Progression. Am J Kidney Dis 2013; 61:855-7. [DOI: 10.1053/j.ajkd.2013.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 03/13/2013] [Indexed: 11/11/2022]
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Lang F, Ritz E, Voelkl J, Alesutan I. Vascular calcification--is aldosterone a culprit? Nephrol Dial Transplant 2013; 28:1080-4. [PMID: 23476041 DOI: 10.1093/ndt/gft041] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In chronic kidney disease (CKD), increased plasma phosphate concentrations cause vascular calcification which substantially contribute to cardiovascular events and increased mortality of CKD patients. Similar to CKD patients, klotho-hypomorphic mice (kl/kl) also suffer from excessive vascular calcification leading to growth deficit, rapid ageing and early death. The hyperphosphataemia of kl/kl mice results from excessive formation of 1,25(OH)2D3 causing excessive intestinal phosphate absorption. Further, kl/kl mice further suffer from hyperaldosteronism and compelling evidence points to an active role of mineralocorticoids in triggering osteoinductive programmes in the vasculature, thus further contributing to the development of vascular calcification. Conversely, in kl/kl mice, the mineralocorticoid receptor antagonist spironolactone decreased the vascular osteoinductive processes and reversed the excessive expression of osteogenic programmes, i.e. type III sodium-dependent phosphate transporter Pit1, tumour necrosis factor α (Tnfα), transcription factors Msx2, Cbfa1/Runx2 and osterix as well as alkaline phosphatase (Alp). In human aortic vascular smooth muscle cells (HAoSMCs), aldosterone alone similarly triggered an 'osteogenic' programme, thus increasing PIT1, TNFα, MSX2, CBFA1/RUNX2 and ALP expression as well as ALP activity and potentiated the effects of phosphate treatment. These effects were again reversed by spironolactone and in addition by PIT1 silencing. The above observations reveal that the severe vascular calcification is not only the result of high plasma phosphate concentrations, but also promoted by aldosterone-driven osteoinductive signalling. Future studies in CKD patients will be required to define the role of aldosterone and the potential impact of its inhibition by spironolactone in the pathophysiology of vascular calcification.
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Affiliation(s)
- Florian Lang
- Department of Physiology, University of Tübingen, Tübingen, Germany.
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