51
|
Selby NM, Blankestijn PJ, Boor P, Combe C, Eckardt KU, Eikefjord E, Garcia-Fernandez N, Golay X, Gordon I, Grenier N, Hockings PD, Jensen JD, Joles JA, Kalra PA, Krämer BK, Mark PB, Mendichovszky IA, Nikolic O, Odudu A, Ong ACM, Ortiz A, Pruijm M, Remuzzi G, Rørvik J, de Seigneux S, Simms RJ, Slatinska J, Summers P, Taal MW, Thoeny HC, Vallée JP, Wolf M, Caroli A, Sourbron S. Magnetic resonance imaging biomarkers for chronic kidney disease: a position paper from the European Cooperation in Science and Technology Action PARENCHIMA. Nephrol Dial Transplant 2018; 33:ii4-ii14. [PMID: 30137584 PMCID: PMC6106645 DOI: 10.1093/ndt/gfy152] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Indexed: 12/13/2022] Open
Abstract
Functional renal magnetic resonance imaging (MRI) has seen a number of recent advances, and techniques are now available that can generate quantitative imaging biomarkers with the potential to improve the management of kidney disease. Such biomarkers are sensitive to changes in renal blood flow, tissue perfusion, oxygenation and microstructure (including inflammation and fibrosis), processes that are important in a range of renal diseases including chronic kidney disease. However, several challenges remain to move these techniques towards clinical adoption, from technical validation through biological and clinical validation, to demonstration of cost-effectiveness and regulatory qualification. To address these challenges, the European Cooperation in Science and Technology Action PARENCHIMA was initiated in early 2017. PARENCHIMA is a multidisciplinary pan-European network with an overarching aim of eliminating the main barriers to the broader evaluation, commercial exploitation and clinical use of renal MRI biomarkers. This position paper lays out PARENCHIMA's vision on key clinical questions that MRI must address to become more widely used in patients with kidney disease, first within research settings and ultimately in clinical practice. We then present a series of practical recommendations to accelerate the study and translation of these techniques.
Collapse
Affiliation(s)
- Nicholas M Selby
- Centre for Kidney Research and Innovation, University of Nottingham, UK
| | - Peter J Blankestijn
- Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter Boor
- Institute of Pathology and Department of Nephrology, RWTH University, Aachen, Germany
| | - Christian Combe
- Service de Néphrologie Transplantation Dialyse Aphérèse, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Kai-Uwe Eckardt
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Berlin, Germany
| | - Eli Eikefjord
- Department of Health and Functioning, Western Norway University of Applied Sciences, Norway
| | | | - Xavier Golay
- Institute of Neurology, University College London, Queen Square, London, UK
| | - Isky Gordon
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Nicolas Grenier
- Service d'Imagerie Diagnostique et Interventionnelle de l'Adulte, Centre Hospitalier Universitaire de Bordeaux Place Amelie Raba-Leon, Bordeaux, France
| | | | - Jens D Jensen
- Departments of Renal and Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Jaap A Joles
- Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Philip A Kalra
- Department of Renal Medicine, Salford Royal Hospital and Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Bernhard K Krämer
- Vth Department of Medicine, University Medical Center Mannheim, Medical Faculty Mannheim of the University Heidelberg, Mannheim, Germany
| | - Patrick B Mark
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Iosif A Mendichovszky
- Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge Biomedical Campus, Cambridge, UK
| | - Olivera Nikolic
- Faculty of Medicine,University of Novi Sad, Center of Radiology, Clinical Centre of Vojvodina, Serbia
| | - Aghogho Odudu
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Albert C M Ong
- Academic Nephrology Unit, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK
| | - Alberto Ortiz
- Nephrology and Hypertension, IIS-Fundacion Jimenez Diaz UAM, Madrid, Spain
| | - Menno Pruijm
- Service of Nephrology and Hypertension, Department of Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Giuseppe Remuzzi
- IRCCS Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy
| | - Jarle Rørvik
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Radiology, Haukeland University Hospital, Bergen, Norway
| | - Sophie de Seigneux
- Service of Nephrology, Department of Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland
| | - Roslyn J Simms
- Academic Nephrology Unit, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK
| | - Janka Slatinska
- Department of Nephrology, Transplant Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Paul Summers
- Department of Medical Imaging and Radiation Sciences, Radiology Division, European Institute of Oncology (IEO), Milan, Italy
- QMRI Tech iSrl, Piazza dei Martiri Pennesi 20, Pescara, Italy
| | - Maarten W Taal
- Centre for Kidney Research and Innovation, University of Nottingham, UK
| | - Harriet C Thoeny
- University of Bern, Inselspital, Bern, Switzerland
- HFR Fribourg, Hôpital Cantonal, Fribourg, Switzerland
| | - Jean-Paul Vallée
- Radiology Department, Geneva University Hospital and University of Geneva, Geneva, Switzerland
| | - Marcos Wolf
- Center for Medical Physics and Biomedical Engineering, MR-Centre of Excellence, Medical University of Vienna, Vienna, Austria
| | - Anna Caroli
- IRCCS Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy
| | - Steven Sourbron
- Leeds Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| |
Collapse
|
52
|
Pivin E, Ponte B, de Seigneux S, Ackermann D, Burnier M, Bochud M, Devuyst O, Pruijm M. FO044UROMODULIN REFLECTS NEPHRON MASS IN THE GENERAL POPULATION AND KIDNEY DONORS. Nephrol Dial Transplant 2018. [DOI: 10.1093/ndt/gfy104.fo044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Edward Pivin
- Nephrology and Hypertension, University Hospital Lausanne (CHUV), Lausanne, Switzerland
| | - Belén Ponte
- Nephrology and Hypertension, University Hospital Geneva (HUG), Geneva, Switzerland
| | - Sophie de Seigneux
- Nephrology and Hypertension, University Hospital Geneva (HUG), Geneva, Switzerland
| | - Daniel Ackermann
- University Clinic for Nephrology and Hypertension, Bern University Hospital, Inselspital, Bern, Switzerland
| | - Michel Burnier
- Nephrology and Hypertension, University Hospital Lausanne (CHUV), Lausanne, Switzerland
| | - Murielle Bochud
- Division of chronic disease, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Olivier Devuyst
- Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - Menno Pruijm
- Nephrology, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| |
Collapse
|
53
|
Dufey Teso A, Lefuel P, de Seigneux S, Lassere-Moutet A, Martin PY, Golay A. [What place for therapeutic education in nephrology ?]. Rev Med Suisse 2018; 14:418-421. [PMID: 29465873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Chronic kidney disease (CKD) usually goes unrecognized for patients until late symptomatic stages. In preterminal CKD, extrarenal substitution methods are usually presented to patients. This is felt like a breakdown, implying major modifications of everyday life. Acquisition of health literacy is necessary for patients with CKD to become autonomous and increase their empowerment toward the disease. Therapeutic education in nephrology plays a major role in improving the care of CKD patients.
Collapse
Affiliation(s)
| | | | | | | | | | - Alain Golay
- Service d'éducation thérapeutique et maladie chronique, HUG, 1211 Genève 14
| |
Collapse
|
54
|
Abstract
Albuminuria is strongly associated with renal and cardiovascular outcomes independently of renal function level. However, the pathophysiology of these associations is debated. In chronic kidney disease (CKD), phosphate retention participates in cardiovascular events and increased cardiovascular mortality. We hypothesised that albuminuria may modulate tubular phosphate handling by the kidney. To verify this hypothesis, we first studied the association between phosphataemia and albuminuria in children with nephrotic syndrome and in adults with CKD. In both cases, higher albuminuria was associated with higher phosphate level, independently of glomerular filtration rate. We further tried to decipher the molecular mechanisms of these observations. Using animal models of nephrotic proteinuria, we could show that albuminuric rats and mice had abnormally elevated sodium-phosphate apical co-transporter expression, despite elevated fibroblast growth factor 23 (FGF23). The FGF23 downstream pathway was inhibited despite elevated FGF23 levels. Klotho protein expression was also lower in proteinuric animals compared to controls. Finally, albumin had no direct effects on phosphate transport in cells. Altogether, we show that albuminuria induces alteration of phosphate tubular handling, independently of glomerular filtration rate. The mechanisms involved appear to include Klotho down-regulation and resistance to FGF23. This observation may link albuminuria to increased cardiovascular disease via altered phosphate handling. Finally, this observation opens up further opportunities to better understand the link between albuminuria, Klotho, FGF23 and phosphate handling.
Collapse
Affiliation(s)
- Sophie de Seigneux
- Service and laboratory of Nephrology, Department of Internal Medicine Specialties and Department of Physiology and Metabolism, University Hospital and University of Geneva, Switzerland
| | - Alexandra Wilhelm-Bals
- Unité Pédiatrique Néphrologique Romande, Department of Paediatrics, University Hospital of Geneva and University Hospital Centre of Lausanne, Switzerland
| | - Marie Courbebaisse
- Service of Functional Explorations, Department of Physiology, Hôpital Européen Georges Pompidou, Paris, France
| |
Collapse
|
55
|
Abstract
Chronic kidney disease (CKD) is defined as an alteration of kidney function and/or structure lasting for more than 3 months and is a major public health issue. Histologically, the severity of CKD correlates with the magnitude of kidney cortical interstitial fibrosis. Estimation of kidney fibrosis is crucial to assess prognosis and guide therapy in both native and allograft kidneys. Biopsy is currently the gold standard for assessing fibrosis with histological techniques. Although this procedure has become safer over recent years, complications and limitations remain. Given these restrictions, new, noninvasive techniques are necessary for the evaluation and follow-up of CKD patients. Radiological methods such as ultrasound and magnetic resonance imaging are emerging for assessment kidney fibrosis. These two techniques have advantages but also limitations. In addition to radiological assessment of fibrosis, urinary and plasma biomarkers are being developed and tested as predictive tools for histological lesions in the kidney. This article reviews the current evidence for these novel techniques in the evaluation of kidney interstitial fibrosis.
Collapse
Affiliation(s)
- Lena Berchtold
- Service of Internal Medicine, Department of Internal Medicine, University Hospital of Geneva, Switzerland; Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Switzerland
| | - Iris Friedli
- Service of Radiology, Department of Radiology and Medical Informatics, University Hospital of Geneva, Switzerland
| | - Jean-Paul Vallée
- Service of Radiology, Department of Radiology and Medical Informatics, University Hospital of Geneva, Switzerland
| | - Solange Moll
- Institute of Clinical Pathology, University Hospital Geneva, Switzerland
| | - Pierre-Yves Martin
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Switzerland
| | - Sophie de Seigneux
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Switzerland
| |
Collapse
|
56
|
Affiliation(s)
- Sophie de Seigneux
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland; and Laboratory of Nephrology, Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Pierre-Yves Martin
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland; and Laboratory of Nephrology, Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| |
Collapse
|
57
|
Friedli I, Crowe LA, de Perrot T, Berchtold L, Martin PY, de Seigneux S, Vallée JP. Comparison of readout-segmented and conventional single-shot for echo-planar diffusion-weighted imaging in the assessment of kidney interstitial fibrosis. J Magn Reson Imaging 2017; 46:1631-1640. [DOI: 10.1002/jmri.25687] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/13/2017] [Indexed: 12/27/2022] Open
Affiliation(s)
- Iris Friedli
- Division of Radiology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Lindsey Alexandra Crowe
- Division of Radiology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Thomas de Perrot
- Division of Radiology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Lena Berchtold
- Division of Nephrology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Pierre-Yves Martin
- Division of Nephrology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Sophie de Seigneux
- Division of Nephrology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Jean-Paul Vallée
- Division of Radiology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| |
Collapse
|
58
|
Gagnebin Y, Tonoli D, Lescuyer P, Ponte B, de Seigneux S, Martin PY, Schappler J, Boccard J, Rudaz S. Metabolomic analysis of urine samples by UHPLC-QTOF-MS: Impact of normalization strategies. Anal Chim Acta 2017; 955:27-35. [DOI: 10.1016/j.aca.2016.12.029] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 12/08/2016] [Accepted: 12/20/2016] [Indexed: 10/20/2022]
|
59
|
Bouatou Y, Koessler T, Oniszczuk J, Zhang SY, Moll S, Audard V, de Seigneux S, Sahali D. Nephrotic Syndrome in Small Cell Lung Cancer and Induction of C-Mip in Podocytes. Am J Kidney Dis 2017; 69:477-480. [PMID: 28063735 DOI: 10.1053/j.ajkd.2016.09.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 09/04/2016] [Indexed: 11/11/2022]
Abstract
Paraneoplastic nephrotic syndrome is often a complication in patients with cancer, and various histologic lesions have been described in the kidney. We report the case of a 76-year-old woman who presented with a podocytopathy that was found to be associated with a small cell lung carcinoma (SCLC). One cycle of carboplatin-etoposide combination therapy led to resolution of nephrotic syndrome and remission of the lung carcinoma. C-Maf-inducing protein (C-Mip) was overexpressed in both podocytes and cancer cells, but was not found in control kidney and lung tissue samples. C-Mip also was absent in SCLC cells from 30 patients without nephrotic syndrome. Exposing cultured podocytes to a sample of our patient's serum that was collected prior to chemotherapy led to disorganization of the podocyte cytoskeleton and induction of C-Mip expression, which was not observed with control serum or our patient's serum sampled after chemotherapy. These observations suggest that C-Mip may play an important role in SCLC-related podocytopathy and that a circulating factor likely induces its expression in the kidney.
Collapse
Affiliation(s)
- Yassine Bouatou
- Division of Nephrology, Geneva University Hospitals, Geneva, Switzerland
| | - Thibaud Koessler
- Division of Oncology, Geneva University Hospitals, Geneva, Switzerland
| | - Julie Oniszczuk
- INSERM, U955, Equipe 21, Créteil, France; Université Paris-Est Créteil Val-de-Marne, Créteil, France; AP-HP, Groupe Hospitalier Henri Mondor-Albert Chenevier, Service de Néphrologie, Créteil, France
| | - Shao-Yu Zhang
- INSERM, U955, Equipe 21, Créteil, France; Université Paris-Est Créteil Val-de-Marne, Créteil, France; AP-HP, Groupe Hospitalier Henri Mondor-Albert Chenevier, Service de Néphrologie, Créteil, France
| | - Solange Moll
- Division of Pathology, Geneva University Hospitals, Geneva, Switzerland
| | - Vincent Audard
- INSERM, U955, Equipe 21, Créteil, France; Université Paris-Est Créteil Val-de-Marne, Créteil, France; AP-HP, Groupe Hospitalier Henri Mondor-Albert Chenevier, Service de Néphrologie, Créteil, France
| | - Sophie de Seigneux
- Division of Nephrology, Geneva University Hospitals, Geneva, Switzerland.
| | - Djillali Sahali
- INSERM, U955, Equipe 21, Créteil, France; Université Paris-Est Créteil Val-de-Marne, Créteil, France; AP-HP, Groupe Hospitalier Henri Mondor-Albert Chenevier, Service de Néphrologie, Créteil, France.
| |
Collapse
|
60
|
Berchtold L, Ponte B, Moll S, Hadaya K, Seyde O, Bachtler M, Vallée JP, Martin PY, Pasch A, de Seigneux S. Phosphocalcic Markers and Calcification Propensity for Assessment of Interstitial Fibrosis and Vascular Lesions in Kidney Allograft Recipients. PLoS One 2016; 11:e0167929. [PMID: 28036331 PMCID: PMC5201285 DOI: 10.1371/journal.pone.0167929] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 11/22/2016] [Indexed: 11/18/2022] Open
Abstract
Renal interstitial fibrosis and arterial lesions predict loss of function in chronic kidney disease. Noninvasive estimation of interstitial fibrosis and vascular lesions is currently not available. The aim of the study was to determine whether phosphocalcic markers are associated with, and can predict, renal chronic histological changes. We included 129 kidney allograft recipients with an available transplant biopsy in a retrospective study. We analyzed the associations and predictive values of phosphocalcic markers and serum calcification propensity (T50) for chronic histological changes (interstitial fibrosis and vascular lesions). PTH, T50 and vitamin D levels were independently associated to interstitial fibrosis. PTH elevation was associated with increasing interstitial fibrosis severity (r = 0.29, p = 0.001), while T50 and vitamin D were protective (r = -0.20, p = 0.025 and r = -0.23, p = 0.009 respectively). On the contrary, fibroblast growth factor 23 (FGF23) and Klotho correlated only modestly with interstitial fibrosis (p = 0.045) whereas calcium and phosphate did not. PTH, vitamin D and T50 were predictors of extensive fibrosis (AUC: 0.73, 0.72 and 0.68 respectively), but did not add to renal function prediction. PTH, FGF23 and T50 were modestly predictive of low fibrosis (AUC: 0.63, 0.63 and 0.61) but did not add to renal function prediction. T50 decreased with increasing arterial lesions (r = -0.21, p = 0.038). The discriminative performance of T50 in predicting significant vascular lesions was modest (AUC 0.61). In summary, we demonstrated that PTH, vitamin D and T50 are associated to interstitial fibrosis and vascular lesions in kidney allograft recipients independently of renal function. Despite these associations, mineral metabolism indices do not show superiority or additive value to fibrosis prediction by eGFR and proteinuria in kidney allograft recipients, except for vascular lesions where T50 could be of relevance.
Collapse
Affiliation(s)
- Lena Berchtold
- Service of Internal Medicine, Department of Internal Medicine, University Hospital of Geneva, Geneva, Switzerland
- Service of Nephrology, Department of Internal Medicine Specialities, University Hospital of Geneva, Geneva, Switzerland
| | - Belen Ponte
- Service of Nephrology, Department of Internal Medicine Specialities, University Hospital of Geneva, Geneva, Switzerland
| | - Solange Moll
- Institute of Clinical Pathology, Departement of Clinical Pathology, University Hospital of Geneva, Geneva, Switzerland
| | - Karine Hadaya
- Service of Nephrology, Department of Internal Medicine Specialities, University Hospital of Geneva, Geneva, Switzerland
| | - Olivia Seyde
- Institute of Clinical Pathology, Departement of Clinical Pathology, University Hospital of Geneva, Geneva, Switzerland
| | - Matthias Bachtler
- Service of Clinical Research, Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Jean-Paul Vallée
- Service of Radiology, Department of Radiology and Medical Informatics, University Hospital of Geneva, Geneva, Switzerland
| | - Pierre-Yves Martin
- Service of Nephrology, Department of Internal Medicine Specialities, University Hospital of Geneva, Geneva, Switzerland
| | - Andreas Pasch
- Service of Clinical Research, Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Sophie de Seigneux
- Service of Nephrology, Department of Internal Medicine Specialities, University Hospital of Geneva, Geneva, Switzerland
| |
Collapse
|
61
|
Berchtold L, Friedli I, Crowe LA, Moll S, Hadaya K, De Perrot T, Vesin C, Martin PY, Vallée JP, de Seigneux S. SP234NONINVASIVE ASSESSMENT OF FIBROSIS BY MAGNETIC RESONANCE IMAGING: VALIDATION OF A NOVEL INDEX FROM T1 MAPPING AND DIFFUSION-WEIGHTED IMAGING IN ANIMALS MODELS AND KIDNEY ALLOGRAFT RECIPIENTS. Nephrol Dial Transplant 2016. [DOI: 10.1093/ndt/gfw163.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
62
|
de Seigneux S, Lundby AKM, Berchtold L, Berg AH, Saudan P, Lundby C. Increased Synthesis of Liver Erythropoietin with CKD. J Am Soc Nephrol 2016; 27:2265-9. [PMID: 26757994 DOI: 10.1681/asn.2015050508] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 12/01/2015] [Indexed: 12/13/2022] Open
Abstract
Anemia of CKD seems to be related to impaired production of renal erythropoietin (Epo). The glycosylation pattern of Epo depends on the synthesizing cell and thus, can indicate its origin. We hypothesized that synthesis of Epo from nonkidney cells increases to compensate for insufficient renal Epo production during CKD. We determined plasma Epo levels and Epo glycosylation patterns in 33 patients with CKD before undergoing dialysis and nine patients with CKD undergoing dialysis. We compared these values with values obtained in healthy volunteers and other controls. Although patients with CKD before undergoing dialysis had median (interquartile range) Epo levels higher than those of healthy controls (13.8 IU/L; interquartile range, 10.0-20.7 IU/L versus 8.4 IU/L; interquartile range, 7.6-9.0 IU/L; P<0.01), these patients were moderately anemic (mean±SD; hemoglobin =118±17 g/L). Detected as the percentage of migrated isoforms (PMI), Epo glycosylation in patients with CKD before undergoing dialysis (PMI=36.1±11.7%) differed from that in healthy controls (PMI=9.2±3.8%; P<0.01) but not from that in umbilical cord plasma (PMI=53.9±10.6%; P>0.05), which contains mainly liver-derived Epo. Furthermore, glycosylation modification correlated with eGFR loss. These results suggest that patients with CKD maintain persistent Epo synthesis despite declining renal function, and this maintenance may result in part from increased liver Epo synthesis.
Collapse
Affiliation(s)
- Sophie de Seigneux
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland; National Center of Competence in Research Kidney.CH,
| | - Anne-Kristine Meinild Lundby
- Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zurich, Switzerland; and
| | - Lena Berchtold
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland
| | - Anders H Berg
- Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Patrick Saudan
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland
| | - Carsten Lundby
- National Center of Competence in Research Kidney.CH, Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zurich, Switzerland; and
| |
Collapse
|
63
|
de Seigneux S, Courbebaisse M, Rutkowski JM, Wilhelm-Bals A, Metzger M, Khodo SN, Hasler U, Chehade H, Dizin E, Daryadel A, Stengel B, Girardin E, Prié D, Wagner CA, Scherer PE, Martin PY, Houillier P, Feraille E. Proteinuria Increases Plasma Phosphate by Altering Its Tubular Handling. J Am Soc Nephrol 2015; 26:1608-18. [PMID: 25349200 PMCID: PMC4483577 DOI: 10.1681/asn.2014010104] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 09/03/2014] [Indexed: 12/28/2022] Open
Abstract
Proteinuria and hyperphosphatemia are cardiovascular risk factors independent of GFR. We hypothesized that proteinuria induces relative phosphate retention via increased proximal tubule phosphate reabsorption. To test the clinical relevance of this hypothesis, we studied phosphate handling in nephrotic children and patients with CKD. Plasma fibroblast growth factor 23 (FGF-23) concentration, plasma phosphate concentration, and tubular reabsorption of phosphate increased during the proteinuric phase compared with the remission phase in nephrotic children. Cross-sectional analysis of a cohort of 1738 patients with CKD showed that albuminuria≥300 mg/24 hours is predictive of higher phosphate levels, independent of GFR and other confounding factors. Albuminuric patients also displayed higher plasma FGF-23 and parathyroid hormone levels. To understand the molecular mechanisms underlying these observations, we induced glomerular proteinuria in two animal models. Rats with puromycin-aminonucleoside-induced nephrotic proteinuria displayed higher renal protein expression of the sodium-phosphate co-transporter NaPi-IIa, lower renal Klotho protein expression, and decreased phosphorylation of FGF receptor substrate 2α, a major FGF-23 receptor substrate. These findings were confirmed in transgenic mice that develop nephrotic-range proteinuria resulting from podocyte depletion. In vitro, albumin did not directly alter phosphate uptake in cultured proximal tubule OK cells. In conclusion, we show that proteinuria increases plasma phosphate concentration independent of GFR. This effect relies on increased proximal tubule NaPi-IIa expression secondary to decreased FGF-23 biologic activity. Proteinuria induces elevation of both plasma phosphate and FGF-23 concentrations, potentially contributing to cardiovascular disease.
Collapse
Affiliation(s)
- Sophie de Seigneux
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland; Laboratory of Renal Physiology and Physiopathology, Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland;
| | - Marie Courbebaisse
- Service of Functional Explorations, Department of Physiology, Hôpital Européen Georges Pompidou, Paris, France; National Institute of Health and Medical Research, U845, and Paris Descartes University, Paris, France
| | - Joseph M Rutkowski
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Alexandra Wilhelm-Bals
- Unité Pédiatrique Néphrologique Romande, Department of Pediatrics, University Hospital of Geneva and University Hospital Center of Lausanne, Lausanne, Switzerland
| | - Marie Metzger
- National Institute of Health and Medical Research, Centre de Recherche en Epidémiologie et Santé des Populations U1018, Villejuif, France
| | - Stellor Nlandu Khodo
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland
| | - Udo Hasler
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland
| | - Hassib Chehade
- Unité Pédiatrique Néphrologique Romande, Department of Pediatrics, University Hospital of Geneva and University Hospital Center of Lausanne, Lausanne, Switzerland
| | - Eva Dizin
- Laboratory of Renal Physiology and Physiopathology, Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Arezoo Daryadel
- Institute of Physiology, University of Zürich, Zürich, Switzerland; and
| | - Bénedicte Stengel
- National Institute of Health and Medical Research, Centre de Recherche en Epidémiologie et Santé des Populations U1018, Villejuif, France
| | - E Girardin
- Unité Pédiatrique Néphrologique Romande, Department of Pediatrics, University Hospital of Geneva and University Hospital Center of Lausanne, Lausanne, Switzerland
| | - Dominique Prié
- National Institute of Health and Medical Research, U845, and Paris Descartes University, Paris, France; Service of Functional Explorations, Department of Physiology, Hôpital Necker-Enfants Malades, Paris, France
| | - Carsten A Wagner
- Institute of Physiology, University of Zürich, Zürich, Switzerland; and
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Pierre-Yves Martin
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland; Laboratory of Renal Physiology and Physiopathology, Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Pascal Houillier
- Service of Functional Explorations, Department of Physiology, Hôpital Européen Georges Pompidou, Paris, France
| | - Eric Feraille
- Service of Nephrology, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland; Laboratory of Renal Physiology and Physiopathology, Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| |
Collapse
|
64
|
Friedli I, Crowe LA, Viallon M, Porter DA, Martin PY, de Seigneux S, Vallée JP. Improvement of renal diffusion-weighted magnetic resonance imaging with readout-segmented echo-planar imaging at 3T. Magn Reson Imaging 2015; 33:701-8. [DOI: 10.1016/j.mri.2015.02.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 02/20/2015] [Indexed: 01/06/2023]
|
65
|
de Seigneux S, Ponte B, Berchtold L, Hadaya K, Martin PY, Pasch A. Living kidney donation does not adversely affect serum calcification propensity and markers of vascular stiffness. Transpl Int 2015; 28:1074-80. [PMID: 25903063 DOI: 10.1111/tri.12595] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/09/2015] [Accepted: 04/17/2015] [Indexed: 12/14/2022]
Abstract
Living kidney donors (LKDs) experience a decline in glomerular filtration rate (GFR) after donation. Calcification propensity (T50 ) can be determined by a blood test predicting all-cause mortality in patients with chronic kidney disease. We studied the impact of kidney donation on T50 and markers of arterial stiffness. We analyzed T50 prospectively before and 1 year after kidney donation in 21 LKDs along with fetuin-A, mineral metabolism markers, kidney length, pulse wave velocity (PWV), augmentation index (AI), and renal resistive index (RRI) as markers of arterial stiffness. We studied the impact of kidney donation on these parameters. LKDs were 54 ± 10 years old and had a GFR of 101 ± 18 ml/min/1.73 m(2) before donation, decreasing to 67 ± 8 ml/min/1.73 m(2) after donation (P < 0.001). Despite this, T50 improved after donation (290 ± 53 to 312 ± 38 min, P = 0.049). This change was inversely related to plasma phosphate (P = 0.03), which declined after donation (P = 0.002). Fetuin-A levels increased after donation (P = 0.01). Upon donation, the length of the remaining kidney increased (P < 0.001) while PWV, AI, and RRI remained unchanged. Calcification propensity was not adversely affected by kidney donation. This indicates that T50 is independent from GFR in LKDs and that kidney donation does neither worsen calcification propensity nor markers of vascular stiffness at 1 year.
Collapse
Affiliation(s)
- Sophie de Seigneux
- Service of Nephrology, University Hospital of Geneva, Geneva, Switzerland
| | - Belen Ponte
- Service of Nephrology, University Hospital of Geneva, Geneva, Switzerland
| | - Lena Berchtold
- Service of Nephrology, University Hospital of Geneva, Geneva, Switzerland
| | - Karine Hadaya
- Service of Nephrology, University Hospital of Geneva, Geneva, Switzerland
| | - Pierre-Yves Martin
- Service of Nephrology, University Hospital of Geneva, Geneva, Switzerland
| | - Andreas Pasch
- Department of Clinical Chemistry, University Hospital and University of Bern, Bern, Switzerland
| |
Collapse
|
66
|
Fumeaux D, de Seigneux S, Chizzolini C, Martin PY. [Renal disease in ANCA-associated vasculitis]. Rev Med Suisse 2014; 10:493-497. [PMID: 24665659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
ANCA-associated vasculitis are systemic disorders characterized by inflammation predominantly involving small vessels. They are the most frequent cause of rapidly progressive glomerulonephritis in the elderly. They originate from complex interactions between genes and environment, resulting in autoimmunity and the generation of antibodies directed against neutrophil cytoplasmic antigens (ANCA), which may have pathogenic potential. Immunosuppressant agents, particularly cyclophosphamide, have considerably improved the prognosis, but infectious complications and relapses remain frequent. Recently, rituximab has been shown to be a good alternative to cyclophosphamide to induce remission. Additional knowledge should result in better clinical outcomes, minimizing side effects.
Collapse
|
67
|
Féraille E, Dizin E, Roth I, Derouette JP, Szanto I, Martin PY, de Seigneux S, Hasler U. NADPH oxidase 4 deficiency reduces aquaporin-2 mRNA expression in cultured renal collecting duct principal cells via increased PDE3 and PDE4 activity. PLoS One 2014; 9:e87239. [PMID: 24466344 PMCID: PMC3900718 DOI: 10.1371/journal.pone.0087239] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 12/19/2013] [Indexed: 11/24/2022] Open
Abstract
The final control of renal water reabsorption occurs in the collecting duct (CD) and relies on regulated expression of aquaporin-2 (AQP2) in principal CD cells. AQP2 transcription is primarily induced by type 2 vasopressin receptor (V2R)-cAMP-protein kinase A (PKA) signaling but also by other factors, including TonEBP and NF-κB. NAPDH oxidase 4 (NOX4) represents a major source of reactive oxygen species (ROS) in the kidney. Because NOX-derived ROS may alter PKA, TonEBP and NF-κB activity, we examined the effects of NOX4 depletion on AQP2 expression. Depleted NOX4 expression by siRNA (siNOX4) in mpkCCDcl4 cells attenuated increased AQP2 mRNA expression by arginine vasopressin (AVP) but not by hypertonicity, which induces both TonEBP and NF-κB activity. AVP-induced AQP2 expression was similarly decreased by the flavoprotein inhibitor diphenyleneiodonium. siNOX4 altered neither TonEBP nor NF-κB activity but attenuated AVP-inducible cellular cAMP concentration, PKA activity and CREB phosphorylation as well as AQP2 mRNA expression induced by forskolin, a potent activator of adenylate cyclase. The repressive effect of siNOX4 on AVP-induced AQP2 mRNA expression was abolished by the non-selective phosphodiesterase (PDE) inhibitor 3-isobutyl-1-methylxanthine (IBMX) and was significantly decreased by selective PDE antagonists cilostamide and rolipram, but not vinpocetine, which respectively target PDE3, PDE4 and PDE1. Thus, by inhibiting PDE3 and PDE4 activity NOX4-derived ROS may contribute to V2R-cAMP-PKA signaling and enhance AQP2 transcription.
Collapse
Affiliation(s)
- Eric Féraille
- Departments of Cellular Physiology and Metabolism, University Medical Center, Geneva, Switzerland
| | - Eva Dizin
- Departments of Cellular Physiology and Metabolism, University Medical Center, Geneva, Switzerland
| | - Isabelle Roth
- Departments of Cellular Physiology and Metabolism, University Medical Center, Geneva, Switzerland
| | - Jean-Paul Derouette
- Departments of Cellular Physiology and Metabolism, University Medical Center, Geneva, Switzerland
| | - Ildiko Szanto
- Departments of Cellular Physiology and Metabolism, University Medical Center, Geneva, Switzerland
- Service of Endocrinology, Diabetology, Hypertension and Nutrition, Department of Medical Specialties, University of Geneva, Geneva, Switzerland
| | - Pierre-Yves Martin
- Service of Nephrology, Department of Medical Specialties, University of Geneva, Geneva, Switzerland
| | - Sophie de Seigneux
- Service of Nephrology, Department of Medical Specialties, University of Geneva, Geneva, Switzerland
| | - Udo Hasler
- Departments of Cellular Physiology and Metabolism, University Medical Center, Geneva, Switzerland
- * E-mail:
| |
Collapse
|
68
|
de Seigneux S, Saudan P. [2013 update in nephrology]. Rev Med Suisse 2014; 10:74-77. [PMID: 24558904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Vasopressin antagonists show for the first time a beneficial effect on ADPKD cyst growth and renal function in a large cohort of patients. In ANCA vasculitis, the 18 months follow-up of Rituximab treatment for induction confirms the safety and efficacy of this therapeutic option. Two studies brought some answers to what is the more appropriate intravenous fluid strategy to decrease the incidence of acute kidney injury in critically ill patients. Regarding mortality in dialysed patients, inconclusive results about the use of calcimimetics to decrease cardiovascular mortality have been reported but there is good evidence that hemodiafiltration with high ultrafiltration volume can decrease significantly the mortality in these
Collapse
Affiliation(s)
- Sophie de Seigneux
- Service de néphrologie, Département des spécialités médicales, HUG, 1211 Genève.
| | - Patrick Saudan
- Service de néphrologie, Département des spécialités médicales, HUG, 1211 Genève
| |
Collapse
|
69
|
Gariani K, de Seigneux S, Moll S. Acute interstitial nephritis after treatment with liraglutide. Am J Kidney Dis 2013; 63:347. [PMID: 24315766 DOI: 10.1053/j.ajkd.2013.10.057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 10/30/2013] [Indexed: 11/11/2022]
|
70
|
Wang YB, Leroy V, Maunsbach AB, Doucet A, Hasler U, Dizin E, Ernandez T, de Seigneux S, Martin PY, Féraille E. Sodium transport is modulated by p38 kinase-dependent cross-talk between ENaC and Na,K-ATPase in collecting duct principal cells. J Am Soc Nephrol 2013; 25:250-9. [PMID: 24179170 DOI: 10.1681/asn.2013040429] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In relation to dietary Na(+) intake and aldosterone levels, collecting duct principal cells are exposed to large variations in Na(+) transport. In these cells, Na(+) crosses the apical membrane via epithelial Na(+) channels (ENaC) and is extruded into the interstitium by Na,K-ATPase. The activity of ENaC and Na,K-ATPase must be highly coordinated to accommodate variations in Na(+) transport and minimize fluctuations in intracellular Na(+) concentration. We hypothesized that, independent of hormonal stimulus, cross-talk between ENaC and Na,K-ATPase coordinates Na(+) transport across apical and basolateral membranes. By varying Na(+) intake in aldosterone-clamped rats and overexpressing γ-ENaC or modulating apical Na(+) availability in cultured mouse collecting duct cells, enhanced apical Na(+) entry invariably led to increased basolateral Na,K-ATPase expression and activity. In cultured collecting duct cells, enhanced apical Na(+) entry increased the basolateral cell surface expression of Na,K-ATPase by inhibiting p38 kinase-mediated endocytosis of Na,K-ATPase. Our results reveal a new role for p38 kinase in mediating cross-talk between apical Na(+) entry via ENaC and its basolateral exit via Na,K-ATPase, which may allow principal cells to maintain intracellular Na(+) concentrations within narrow limits.
Collapse
Affiliation(s)
- Yu-Bao Wang
- Service of Nephrology, Department of Cell Physiology and Metabolism, University Medical Center, Geneva, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
71
|
Dizin E, Hasler U, Nlandu-Khodo S, Fila M, Roth I, Ernandez T, Doucet A, Martin PY, Feraille E, de Seigneux S. Albuminuria induces a proinflammatory and profibrotic response in cortical collecting ducts via the 24p3 receptor. Am J Physiol Renal Physiol 2013; 305:F1053-63. [PMID: 23884139 DOI: 10.1152/ajprenal.00006.2013] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Albuminuria is strongly associated with progressive kidney tubulo-interstitial damage and chronic kidney disease (CKD) progression. In proteinuric nephropathies, albumin reabsorption by the proximal tubule is saturated and the distal nephron is exposed to high concentrations of luminal albumin that may produce adverse effects. Since proximal tubular cells exposed to albuminuria exhibit a proinflammatory and profibrotic response, we assessed the effect of albuminuria in the collecting duct (CD). With the use of kidney sections and isolated cortical CDs (CCDs) from puromycin-aminonucleoside-induced nephrotic rats (PAN rats) exhibiting proteinuria, immunofluorescence microscopy revealed internalized albumin in CD cells. In these proteinuric rats, increased expression levels of cytokines and profibrotic signaling markers were detected in isolated CCDs and bands of inflammatory fibrosis could be observed around CDs. Albumin endocytosis was confirmed by FITC-albumin uptake in cultured murine CCD (mCCDcl1) cells. Exposure of mCCDcl1 cells to albumin induced NF-κB activation as assessed by luciferase reporter gene assay, nuclear translocation of NF-κB p65 subunit, and increased NF-κB target gene expression. Moreover, albuminuria-like condition results in transforming growth factor-β1 (TGF-β1) overexpression and the upregulation of profibrotic signaling markers such as Snail or vimentin via an autocrine mechanism. In mCCDcl1 cells, neutrophil gelatinase-associated lipocalin (NGAL)/lipocalin-2/24p3 receptor (24p3R) mediates albumin endocytosis as well as activation of NF-κB and TGF-β1 signaling pathways. Therefore, CD may play a key role in initiation and/or progression of inflammation and fibrosis in response to proteinuria.
Collapse
Affiliation(s)
- Eva Dizin
- Univ. of Geneva, Univ. Medical Center, Service of Nephrology, Dept. of Physiology and Metabolism, 1 rue Michel Servet, CH-1211 Geneva 4, Switzerland.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
72
|
Mavrakanas TA, Bouatou Y, Samer C, de Seigneux S, Meyer P. Carbimazole-Induced, ANCA-Associated, Crescentic Glomerulonephritis: Case Report and Literature Review. Ren Fail 2013; 35:414-7. [DOI: 10.3109/0886022x.2012.760356] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
73
|
Nlandu Khodo S, Dizin E, Sossauer G, Szanto I, Martin PY, Feraille E, Krause KH, de Seigneux S. NADPH-oxidase 4 protects against kidney fibrosis during chronic renal injury. J Am Soc Nephrol 2012; 23:1967-76. [PMID: 23100220 DOI: 10.1681/asn.2012040373] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
NADPH oxidases synthesize reactive oxygen species that may participate in fibrosis progression. NOX4 and NOX2 are NADPH oxidases expressed in the kidneys, with the former being the major renal isoform, but their contribution to renal disease is not well understood. Here, we used the unilateral urinary obstruction model of chronic renal injury to decipher the role of these enzymes using wild-type, NOX4-, NOX2-, and NOX4/NOX2-deficient mice. Compared with wild-type mice, NOX4-deficient mice exhibited more interstitial fibrosis and tubular apoptosis after obstruction, with lower interstitial capillary density and reduced expression of hypoxia-inducible factor-1α and vascular endothelial growth factor in obstructed kidneys. Furthermore, NOX4-deficient kidneys exhibited increased oxidative stress. With NOX4 deficiency, renal expression of other NOX isoforms was not altered but NRF2 protein expression was reduced under both basal and obstructed conditions. Concomitant deficiency of NOX2 did not modify the phenotype exhibited by NOX4-deficient mice after obstruction. NOX4 silencing in a mouse collecting duct (mCCD(cl1)) cell line increased TGF-β1-induced apoptosis and decreased NRF2 protein along with expression of its target genes. In addition, NOX4 silencing decreased hypoxia-inducible factor-1α and expression of its target genes in response to hypoxia. In summary, these results demonstrate that the absence of NOX4 promotes kidney fibrosis, independent of NOX2, through enhanced tubular cell apoptosis, decreased microvascularization, and enhanced oxidative stress. Thus, NOX4 is crucial for the survival of kidney tubular cells under injurious conditions.
Collapse
Affiliation(s)
- Stellor Nlandu Khodo
- Department of Cell Physiology and Metabolism, University Medical Center, 1 rue Michel Servet, 1211 Geneva, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
74
|
de Seigneux S, Ponte B, Weiss L, Pugin J, Romand JA, Martin PY, Saudan P. Epoetin administrated after cardiac surgery: effects on renal function and inflammation in a randomized controlled study. BMC Nephrol 2012; 13:132. [PMID: 23033926 PMCID: PMC3506492 DOI: 10.1186/1471-2369-13-132] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 09/17/2012] [Indexed: 12/31/2022] Open
Abstract
Background Experimentally, erythropoietin (EPO) has nephroprotective as well as immunomodulatory properties when administered after ischemic renal injury. We tested the hypothesis that different doses of recombinant human EPO administered to patients after cardiac surgery would minimize kidney lesions and the systemic inflammatory response, thereby decreasing acute kidney injury (AKI) incidence. Methods In this double-blinded randomized control study, 80 patients admitted to the ICU post-cardiac surgery were randomized by computer to receive intravenously isotonic saline (n = 40) versus α-Epoetin (n = 40): either 40000 IU (n = 20) or 20000 IU (n = 20). The study lasted one year. The primary outcome was the change in urinary NGAL concentration from baseline and 48 h after EPO injection. Creatinine, cystatine C and urinary NGAL levels were measured on the day of randomization and 2–4 days after EPO injection. To assess acute inflammatory response, serum cytokines (IL6 and IL8) were measured at randomization and four days after r-HuEPO injection. Patients and care-takers were blinded for the assignment. Results No patient was excluded after randomization. Patient groups did not differ in terms of age, gender, comorbidities and renal function at randomization. The rate of AKI assessed by AKIN criteria was 22.5% in our population. EPO treatment did not significantly modify the difference in uNGAl between 48 hours and randomization compared to placebo [2.5 ng/ml (−17.3; 22.5) vs 0.7 ng/ml (−31.77; 25.15), p = 0.77] and the incidence of AKI was similar. Inflammatory cytokines levels were not influenced by EPO treatment. Mortality and hospital stays were similar between the groups and no adverse event was recorded. Conclusion In this randomized-controlled trial, α-Epoetin administrated after cardiac surgery, although safe, demonstrated neither nephroprotective nor anti-inflammatory properties. Trial registration number NCT00676234
Collapse
Affiliation(s)
- Sophie de Seigneux
- Service of Nephrology, Department of Medical Specialties, Geneva University Hospitals, Rue Gabrielle-Perret Gentil 4, 1211, Geneva, Switzerland
| | | | | | | | | | | | | |
Collapse
|
75
|
Haba-Rubio J, de Seigneux S, Heinzer R. Troubles du sommeil et maladie rénale chronique. Nephrol Ther 2012; 8:74-80. [DOI: 10.1016/j.nephro.2011.07.408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Revised: 07/01/2011] [Accepted: 07/17/2011] [Indexed: 12/27/2022]
|
76
|
de Seigneux S, Klopfenstein CE, Iselin C, Martin PY. The risk of acute kidney injury following laparoscopic surgery in a chronic kidney disease patient. NDT Plus 2011; 4:339-41. [PMID: 25984183 PMCID: PMC4421741 DOI: 10.1093/ndtplus/sfr071] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 05/10/2011] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sophie de Seigneux
- Service of Nephrology, Department of Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland
| | - Claude-Eric Klopfenstein
- Service of Anaesthesiology, Department of anaesthesiology, University Hospital of Geneva, Geneva, Switzerland
| | - Christophe Iselin
- Service of Urology, Department of Surgery, University Hospital of Geneva, Geneva, Switzerland
| | - Pierre-Yves Martin
- Service of Nephrology, Department of Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland
| |
Collapse
|
77
|
Zaidan M, Cervera-Pierot P, de Seigneux S, Dahan K, Fabiani B, Callard P, Ronco P, Aucouturier P. Evidence of follicular T-cell implication in a case of IgG4-related systemic disease with interstitial nephritis. Nephrol Dial Transplant 2011; 26:2047-50. [DOI: 10.1093/ndt/gfr097] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
|
78
|
de Seigneux S, Bindi P, Debiec H, Alyanakian MA, Aymard B, Callard P, Ronco P, Aucouturier P. Immunoglobulin Deposition Disease With a Membranous Pattern and a Circulating Monoclonal Immunoglobulin G With Charge-Dependent Aggregation Properties. Am J Kidney Dis 2010; 56:117-21. [PMID: 20471736 DOI: 10.1053/j.ajkd.2010.03.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 03/01/2010] [Indexed: 11/11/2022]
|
79
|
Olesen ETB, de Seigneux S, Wang G, Lütken SC, Frøkiaer J, Kwon TH, Nielsen S. Rapid and segmental specific dysregulation of AQP2, S256-pAQP2 and renal sodium transporters in rats with LPS-induced endotoxaemia. Nephrol Dial Transplant 2009; 24:2338-49. [PMID: 19193739 DOI: 10.1093/ndt/gfp011] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Acute renal failure (ARF) is a frequent complication of sepsis. Characteristics of ARF in sepsis are impaired urinary concentration, increased natriuresis and decreased glomerular filtration rate (GFR), in which inducible nitric oxide synthase (iNOS) has been revealed to play a role. Aims. We aimed to investigate renal water and sodium excretion and in parallel the segmental regulation of renal AQP2 and major sodium transporters in rats with acute LPS-induced endotoxaemia. Next, we aimed to examine the changes of iNOS expression and activated macrophage infiltration in the kidney and the effects of iNOS inhibition on AQP2 and NKCC2 expression in LPS rats. METHODS Rats were treated with LPS (i.p.) or with LPS + iNOS inhibitor L-NIL, and 6 h later kidneys were subjected to semiquantitative immunoblotting and immunohistochemistry. RESULTS Polyuria and increased natriuresis were seen 6 h after LPS injection alongside downregulation of both AQP2 and S256-phosphorylated AQP2 in CTX/OSOM and ISOM but not in inner medulla (IM). Thick ascending limb sodium transporters NHE3 and NKCC2 were downregulated in ISOM and NaPi2 was decreased in CTX/OSOM, whereas NCC and ENaC were not consistently downregulated. Immunolabelling intensity of iNOS was increased in vascular structures and transitional epithelium, and an infiltration of activated macrophages was seen in CTX and ISOM. L-NIL co-treatment prevented the downregulation of NKCC2 but not AQP2 in LPS rats. CONCLUSIONS Early downregulation of AQP2 and sodium transporters takes place segmentally in the kidney after LPS administration. In addition, an infiltration of activated macrophages and increased iNOS expression may play a role in the urinary concentrating defect in acute LPS-induced entotoxaemia.
Collapse
Affiliation(s)
- Emma T B Olesen
- The Water and Salt Research Centre, Institute of Anatomy, University of Aarhus, Aarhus, Denmark
| | | | | | | | | | | | | |
Collapse
|
80
|
de Seigneux S, Leroy V, Ghzili H, Rousselot M, Nielsen S, Rossier BC, Martin PY, Féraille E. NF-kappaB inhibits sodium transport via down-regulation of SGK1 in renal collecting duct principal cells. J Biol Chem 2008; 283:25671-25681. [PMID: 18586672 DOI: 10.1074/jbc.m803812200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tubulointerstitial inflammation is a common feature of renal diseases. We have investigated the relationship between inflammation and Na(+) transport in the collecting duct (CD) using the mCCD(cl1) and mpkCDD(cl4) principal cell models. Lipopolysaccharide (LPS) decreased basal and aldosterone-stimulated amiloride-sensitive transepithelial current in a time-dependent manner. This effect was associated with a decrease in serum and glucocorticoid-regulated kinase 1 (SGK1) mRNA and protein levels followed by a decrease in epithelial sodium channel (ENaC) alpha-subunit mRNA levels. The LPS-induced decrease in SGK1 expression was confirmed in isolated rat CD. This decreased expression of either SGK1 or the ENaC alpha-subunit was not due to enhanced degradation of mRNA. In contrast, LPS inhibited transcriptional activity of the SGK1 promoter measured by luciferase-reporter gene assay. The effect of LPS was not mediated by inhibition of mineralocorticoid or glucocorticoid receptor, because expression of both receptors was unchanged and blockade of either receptor by spironolactone or RU486, respectively, did not prevent the down-regulation of SGK1. The effect of LPS was mediated by the canonical NF-kappaB pathway, as overexpression of a constitutively active mutant, IKKbeta (inhibitor of nuclear factor kappaB kinase-beta) decreased SGK1 mRNA levels, and knockdown of p65 NF-kappaB subunit by small interfering RNA increased SGK1 mRNA levels. Chromatin immunoprecipitation showed that LPS increased p65 binding to two NF-kappaB sites along the SGK1 promoter. In conclusion, we show that activation of the NF-kappaB pathway down-regulates SGK1 expression, which might lead to decreased ENaC alpha-subunit expression, ultimately resulting in decreased Na(+) transport.
Collapse
Affiliation(s)
- Sophie de Seigneux
- Service de Néphrologie, Fondation pour Recherches Médicales, 1211 Genève 4, Switzerland
| | - Valérie Leroy
- Service de Néphrologie, Fondation pour Recherches Médicales, 1211 Genève 4, Switzerland
| | - Hafida Ghzili
- Service de Néphrologie, Fondation pour Recherches Médicales, 1211 Genève 4, Switzerland
| | - Martine Rousselot
- Service de Néphrologie, Fondation pour Recherches Médicales, 1211 Genève 4, Switzerland
| | - Søren Nielsen
- The Water and Salt Research Center, Institute of Anatomy, University of Aarhus, 8000 Aarhus, Denmark
| | - Bernard C Rossier
- Department of Pharmacology and Toxicology, University of Lausanne, 1005 Lausanne, Switzerland
| | - Pierre-Yves Martin
- Service de Néphrologie, Fondation pour Recherches Médicales, 1211 Genève 4, Switzerland
| | - Eric Féraille
- Service de Néphrologie, Fondation pour Recherches Médicales, 1211 Genève 4, Switzerland.
| |
Collapse
|
81
|
Bustamante M, Hasler U, Leroy V, de Seigneux S, Dimitrov M, Mordasini D, Rousselot M, Martin PY, Féraille E. Calcium-sensing receptor attenuates AVP-induced aquaporin-2 expression via a calmodulin-dependent mechanism. J Am Soc Nephrol 2007; 19:109-16. [PMID: 18032798 DOI: 10.1681/asn.2007010092] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Recent evidence suggests that arginine vasopressin (AVP)-dependent aquaporin-2 expression is modulated by the extracellular calcium-sensing receptor (CaSR) in principal cells of the collecting duct, but the signaling pathways mediating this effect are unknown. Using a mouse cortical collecting duct cell line (mpkCCD(cl4)), we found that increasing the concentration of apical extracellular calcium or treating with the CaSR agonists neomycin or Gd(3+) attenuated AVP-dependent accumulation of aquaporin-2 mRNA and protein; CaSR gene-silencing prevented this effect. Calcium reduced the AVP-induced accumulation of cAMP, but this did not occur by increased degradation of cAMP by phosphodiesterases or by direct inhibition of adenylate cyclase. Notably, the effect of extracellular calcium on AVP-dependent aquaporin-2 expression was prevented by inhibition of calmodulin. In summary, our results show that high concentrations of extracellular calcium attenuate AVP-induced aquaporin-2 expression by activating the CaSR and reducing coupling efficiency between V(2) receptor and adenylate cyclase via a calmodulin-dependent mechanism in cultured cortical collecting duct cells.
Collapse
Affiliation(s)
- Mauro Bustamante
- Service of Nephrology, Fondation pour Recherches Médicales, 64 Ave de la Roseraie, CH-1211 Genève 4, Switzerland
| | | | | | | | | | | | | | | | | |
Collapse
|
82
|
de Seigneux S, Nielsen J, Olesen ETB, Dimke H, Kwon TH, Frøkiaer J, Nielsen S. Long-term aldosterone treatment induces decreased apical but increased basolateral expression of AQP2 in CCD of rat kidney. Am J Physiol Renal Physiol 2007; 293:F87-99. [PMID: 17376764 DOI: 10.1152/ajprenal.00431.2006] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of the present studies was to determine the effects of high-dose aldosterone and dDAVP treatment on renal aquaporin-2 (AQP2) regulation and urinary concentration. Rats were treated for 6 days with either vehicle (CON; n = 8), dDAVP (0.5 ng/h, dDAVP, n = 10), aldosterone (Aldo, 150 μg/day, n = 10) or combined dDAVP and aldosterone treatment (dDAVP+Aldo, n = 10) and had free access to water with a fixed food intake. Aldosterone treatment induced hypokalemia, decreased urine osmolality, and increased the urine volume and water intake in ALDO compared with CON and dDAVP+Aldo compared with dDAVP. Immunohistochemistry and semiquantitative laser confocal microscopy revealed a distinct increase in basolateral domain AQP2 labeling in cortical collecting duct (CCD) principal cells and a reduction in apical domain labeling in Aldo compared with CON rats. Given the presence of hypokalemia in aldosterone-treated rats, we studied dietary-induced hypokalemia in rats, which also reduced apical AQP2 expression in the CCD but did not induce any increase in basolateral AQP2 expression in the CCD as observed with aldosterone treatment. The aldosterone-induced basolateral AQP2 expression in the CCD was thus independent of hypokalemia but was dependent on the presence of sodium and aldosterone. This redistribution was clearly blocked by mineralocorticoid receptor blockade. The increased basolateral expression of AQP2 induced by aldosterone may play a significant role in water metabolism in conditions with increased sodium reabsorption in the CCD.
Collapse
Affiliation(s)
- Sophie de Seigneux
- The Water and Salt Research Center, University of Aarhus, DK-8000 Aarhus C, Denmark
| | | | | | | | | | | | | |
Collapse
|
83
|
de Seigneux S, Malte H, Dimke H, Frøkiaer J, Nielsen S, Frische S. Renal compensation to chronic hypoxic hypercapnia: downregulation of pendrin and adaptation of the proximal tubule. Am J Physiol Renal Physiol 2006; 292:F1256-66. [PMID: 17182533 DOI: 10.1152/ajprenal.00220.2006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The molecular basis for the renal compensation to respiratory acidosis and specifically the role of pendrin in this condition are unclear. Therefore, we studied the adaptation of the proximal tubule and the collecting duct to respiratory acidosis. Male Wistar-Hannover rats were exposed to either hypercapnia and hypoxia [8% CO(2) and 13% O(2) (hypercapnic, n = 6) or normal air (controls, n = 6)] in an environmental chamber for 10 days and were killed under the same atmosphere. In hypercapnic rats, arterial pH was lower than controls (7.31 +/- 0.01 vs. 7.39 +/- 0.01, P = 0.03), blood HCO(3)(-) concentration was increased (42 +/- 0.9 vs. 32 +/- 0.24 mM, P < 0.001), arterial Pco(2) was increased (10.76 +/- 0.4 vs. 7.20 +/- 0.4 kPa, P < 0.001), and plasma chloride concentration was decreased (92.2 +/- 0.7 vs. 97.2 +/- 0.5 mM, P < 0.001). Plasma aldosterone levels were unchanged. In the proximal tubule, immunoblotting showed an increased expression of sodium/bicarbonate exchanger protein (188 +/- 22 vs. 100 +/- 11%, P = 0.005), confirmed by immunohistochemistry. Total Na/H exchanger protein expression in the cortex was unchanged by immunoblotting (119 +/- 10 vs. 100 +/- 11%, P = 0.27) and immunohistochemistry. In the cortex, the abundance of pendrin was decreased (51 +/- 9 vs. 100 +/- 7%, P = 0.003) by immunoblotting. Immunohistochemistry revealed that this decrease was clear in both cortical collecting ducts (CCDs) and connecting tubules (CNTs). This demonstrates that pendrin expression can be regulated in acidotic animals with no changes in aldosterone levels and no external chloride load. This reduction of pendrin expression may help in redirecting the CNT and CCD toward chloride excretion and bicarbonate reabsorption, contributing to the increased plasma bicarbonate and decreased plasma chloride of chronic respiratory acidosis.
Collapse
Affiliation(s)
- Sophie de Seigneux
- The Water and Salt Research Center, Institute of Anatomy, Bldg. 1234, Univ. of Aarhus, DK-8000 Aarhus C, Denmark
| | | | | | | | | | | |
Collapse
|
84
|
de Seigneux S, Kim SW, Hemmingsen SC, Frøkiaer J, Nielsen S. Increased expression but not targeting of ENaC in adrenalectomized rats with PAN-induced nephrotic syndrome. Am J Physiol Renal Physiol 2006; 291:F208-17. [PMID: 16403831 DOI: 10.1152/ajprenal.00399.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Sodium retention is a hallmark of nephrotic syndrome (NS). Puromycin aminonucleoside (PAN)-induced NS is associated with high aldosterone levels and increased ENaC expression and apical targeting. However, the mechanisms associated with increased apical targeting of ENaC in NS remain undefined, and it is unclear whether this is secondary to high aldosterone levels and whether aldosterone and/or apical ENaC targeting are important for the development of sodium retention. This study aimed at uncovering 1) whether aldosterone is essential for sodium retention in PAN-induced NS, 2) whether ENaC expression or apical targeting is secondary to high aldosterone levels, and 3) the role of aldosterone in the dysregulation of sodium transporters in NS. Puromycin treatment of adrenalectomized (ADX) rats supplemented with dexamethasone induced sodium retention despite the absence of aldosterone. Immunocytochemical analyses revealed an absence of enhanced apical targeting of ENaC subunits in PAN-treated ADX (ADX-PAN) rats, with distribution of labeling similar to adrenalectomized dexamethasone-treated control rats (ADX). Moreover, ENaC subunit abundance was increased in ADX-PAN rats. The abundance of aquaporin-2 was unchanged, whereas apical targeting was enhanced. Key sodium transporters were downregulated as previously observed in nonadrenalectomized puromycin-treated rats (Kim SW, Wang W, Nielsen J, Praetorius J, Kwon TH, Knepper MA, Frøkiaer J, and Nielsen S. Am J Physiol Renal Physiol 286: F922-F935, 2004), whereas the global expression of the alpha1-subunit of the Na-K-ATPase was unchanged. In conclusion, PAN treatment in the absence of aldosterone induced sodium retention, increased ENaC expression, but did not change the subcellular distribution of ENaC. This indicates that the previously observed enhanced apical targeting of ENaC in PAN-induced NS (Kim SW, Wang W, Nielsen J, Praetorius J, Kwon TH, Knepper MA, Frøkiaer J, and Nielsen S. Am J Physiol Renal Physiol 286: F922-F935, 2004) is caused by aldosterone and that development of sodium retention can occur in the absence of aldosterone in NS.
Collapse
Affiliation(s)
- Sophie de Seigneux
- The Water and Salt Research Center, Bldg. 233/234, University of Aarhus, and Institute of Clinical Medicine, Aarhus University Hospital, Denmark
| | | | | | | | | |
Collapse
|
85
|
Kim SW, Schou UK, Peters CD, de Seigneux S, Kwon TH, Knepper MA, Jonassen TEN, Frøkiaer J, Nielsen S. Increased apical targeting of renal epithelial sodium channel subunits and decreased expression of type 2 11beta-hydroxysteroid dehydrogenase in rats with CCl4-induced decompensated liver cirrhosis. J Am Soc Nephrol 2005; 16:3196-210. [PMID: 16192424 DOI: 10.1681/asn.2004080721] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
It was hypothesized that dysregulation of renal epithelial sodium channel (ENaC) subunits and/or 11beta-hydroxysteroid dehydrogenase (11betaHSD2) may play a role in the increased sodium retention in liver cirrhosis (LC). Experimental LC was induced in rats by CCl(4) (1 ml/kg, intraperitoneally, twice a week) for 12 wk (protocol 1) or for 11 wk (protocol 2). In both protocols, one group of rats with cirrhosis showed significantly decreased urinary sodium excretion and urinary Na/K ratio (group A), whereas a second group exhibited normal urinary sodium excretion (group B) compared with controls, even though extensive ascites was seen in both groups of rats with cirrhosis. In group A, protein abundance of alpha-ENaC was unchanged, whereas beta-ENaC abundance was decreased in the cortex/outer stripe of outer medulla compared with controls. The gamma-ENaC underwent a complex change associated with increased abundance of the 70-kD band with a concomitant decrease in the main 85-kD band, corresponding to an aldosterone effect. In contrast, no changes in the abundance of ENaC subunit were observed in group B. Immunoperoxidase microscopy revealed an increased apical targeting of alpha-, beta-, and gamma-ENaC subunits in distal convoluted tubule (DCT2), connecting tubule (CNT), and cortical and medullary collecting duct segments in group A but not in group B. Immunolabeling intensity of 11betaHSD2 in the DCT2, CNT, and cortical collecting duct was significantly reduced in group A but not in group B, and this was confirmed by immunoblotting. In conclusion, increased apical targeting of ENaC subunits combined with diminished abundance of 11betaHSD2 in the DCT2, CNT, and cortical collecting duct is likely to play a role in the sodium retaining stage of liver cirrhosis.
Collapse
Affiliation(s)
- Soo Wan Kim
- The Water and Salt Research Center, University of Aarhus, Aarhus, Denmark DK-8000
| | | | | | | | | | | | | | | | | |
Collapse
|
86
|
Kim SW, de Seigneux S, Sassen MC, Lee J, Kim J, Knepper MA, Frøkiaer J, Nielsen S. Increased apical targeting of renal ENaC subunits and decreased expression of 11betaHSD2 in HgCl2-induced nephrotic syndrome in rats. Am J Physiol Renal Physiol 2005; 290:F674-87. [PMID: 16189294 DOI: 10.1152/ajprenal.00084.2005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nephrotic syndrome is often accompanied by sodium retention and generalized edema. We hypothesize that dysregulation of the epithelial sodium channel (ENaC) and/or of sodium (co)transporters may be responsible for the increased sodium retention associated with HgCl(2)-induced nephropathy. In addition, we examined the hypothesis that the expression of type 2 11beta-hydroxysteroid dehydrogenase (11betaHSD2) is reduced, contributing to the enhanced mineralocorticoid activity. Membranous nephropathy was induced in Brown Norway rats by repeated injections of HgCl(2) (1 mg/kg sc), whereas the control group received only vehicle. After 13 days of treatment, the abundance of ENaC subunits, sodium (co)transporters, and 11betaHSD2 in the kidney was examined by immunoblotting and immunohistochemistry. HgCl(2) treatment induced marked proteinuria, hypoalbuminemia, decreased urinary sodium excretion, and ascites. The protein abundance of alpha-ENaC was increased in the cortex/outer stripe of outer medulla (OSOM) and inner stripe of the outer medulla (ISOM). The protein abundances of beta-ENaC and gamma-ENaC were decreased in the cortex/OSOM while increased in the ISOM. Immunoperoxidase microscopy demonstrated increased targeting of ENaC subunits to the apical plasma membrane in the distal convoluted tubule, connecting tubule, and cortical and medullary collecting duct segments. Moreover, 11betaHSD2 abundance was decreased in cortex/OSOM and ISOM. The protein abundances of type 3 Na/H exchanger (NHE3), Na-K-2Cl cotransporter (NKCC2), and thiazide-sensitive Na-Cl cotransporter (NCC) were decreased. Moreover, the abundance of the alpha-1 subunit of the Na-K-ATPase was decreased in the cortex/OSOM and ISOM but remained unchanged in the inner medulla. These results suggest that increased apical targeting of ENaC subunits combined with diminished abundance of 11betaHSD2 may contribute to sodium retention associated with HgCl(2)-induced nephrotic syndrome. The decreased abundance of NHE3, NKCC2, NCC, and Na-K-ATPase may play a compensatory role in promoting sodium excretion.
Collapse
Affiliation(s)
- Soo Wan Kim
- The Water and Salt Research Center, Bldg. 233/234, University of Aarhus, DK-8000 Aarhus C, Denmark
| | | | | | | | | | | | | | | |
Collapse
|