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Olinger E, Schaeffer C, Kidd K, Elhassan EAE, Cheng Y, Dufour I, Schiano G, Mabillard H, Pasqualetto E, Hofmann P, Fuster DG, Kistler AD, Wilson IJ, Kmoch S, Raymond L, Robert T, Eckardt KU, Bleyer AJ, Köttgen A, Conlon PJ, Wiesener M, Sayer JA, Rampoldi L, Devuyst O. An intermediate-effect size variant in UMOD confers risk for chronic kidney disease. Proc Natl Acad Sci U S A 2022; 119:e2114734119. [PMID: 35947615 PMCID: PMC9388113 DOI: 10.1073/pnas.2114734119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 05/04/2022] [Indexed: 12/12/2022] Open
Abstract
The kidney-specific gene UMOD encodes for uromodulin, the most abundant protein excreted in normal urine. Rare large-effect variants in UMOD cause autosomal dominant tubulointerstitial kidney disease (ADTKD), while common low-impact variants strongly associate with kidney function and the risk of chronic kidney disease (CKD) in the general population. It is unknown whether intermediate-effect variants in UMOD contribute to CKD. Here, candidate intermediate-effect UMOD variants were identified using large-population and ADTKD cohorts. Biological and phenotypical effects were investigated using cell models, in silico simulations, patient samples, and international databases and biobanks. Eight UMOD missense variants reported in ADTKD are present in the Genome Aggregation Database (gnomAD), with minor allele frequency (MAF) ranging from 10-5 to 10-3. Among them, the missense variant p.Thr62Pro is detected in ∼1/1,000 individuals of European ancestry, shows incomplete penetrance but a high genetic load in familial clusters of CKD, and is associated with kidney failure in the 100,000 Genomes Project (odds ratio [OR] = 3.99 [1.84 to 8.98]) and the UK Biobank (OR = 4.12 [1.32 to 12.85). Compared with canonical ADTKD mutations, the p.Thr62Pro carriers displayed reduced disease severity, with slower progression of CKD and an intermediate reduction of urinary uromodulin levels, in line with an intermediate trafficking defect in vitro and modest induction of endoplasmic reticulum (ER) stress. Identification of an intermediate-effect UMOD variant completes the spectrum of UMOD-associated kidney diseases and provides insights into the mechanisms of ADTKD and the genetic architecture of CKD.
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Affiliation(s)
- Eric Olinger
- Institute of Physiology, University of Zurich, CH-8057 Zurich, Switzerland
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE1 3BZ, United Kingdom
| | - Céline Schaeffer
- Molecular Genetics of Renal Disorders, Division of Genetics and Cell Biology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale San Raffaele, Milan, 20132 Italy
| | - Kendrah Kidd
- Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, NC 27101
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, 128 08 Prague, Czech Republic
| | - Elhussein A. E. Elhassan
- Division of Nephrology, Beaumont General Hospital, 1297 Dublin, Ireland
- Department of Medicine, Royal College of Surgeons in Ireland, 1297 Dublin, Ireland
| | - Yurong Cheng
- Institute of Genetic Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, D-79106 Freiburg, Germany
- Faculty of Biology, University of Freiburg, D-79106 Freiburg, Germany
| | - Inès Dufour
- Institute of Physiology, University of Zurich, CH-8057 Zurich, Switzerland
- Division of Nephrology, Cliniques Universitaires Saint-Luc, 1200 Brussels, Belgium
| | - Guglielmo Schiano
- Institute of Physiology, University of Zurich, CH-8057 Zurich, Switzerland
| | - Holly Mabillard
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE1 3BZ, United Kingdom
- Renal Services, Newcastle Upon Tyne Hospitals National Health Service Trust, Newcastle upon Tyne NE7 7DN, United Kingdom
| | - Elena Pasqualetto
- Molecular Genetics of Renal Disorders, Division of Genetics and Cell Biology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale San Raffaele, Milan, 20132 Italy
| | - Patrick Hofmann
- Institute of Physiology, University of Zurich, CH-8057 Zurich, Switzerland
| | - Daniel G. Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland
| | - Andreas D. Kistler
- Department of Medicine, Cantonal Hospital Frauenfeld, 8501 Frauenfeld, Switzerland
| | - Ian J. Wilson
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE1 3BZ, United Kingdom
| | - Stanislav Kmoch
- Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, NC 27101
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, 128 08 Prague, Czech Republic
| | - Laure Raymond
- Genetics Department, Laboratoire Eurofins Biomnis, Lyon, 69007 France
| | - Thomas Robert
- Centre de Néphrologie et Transplantation Rénale, Centre Hospitalier Universitaire (CHU) la Conception, Assistance Publique - Hôpitaux de Marseille (AP-HM), Marseille, 13005 France
- Marseille Medical Genetics, Bioinformatics & Genetics, Unité Mixte de Recherche (UMR)_S910, Aix-Marseille Université, Marseille, 13005 France
| | | | - Kai-Uwe Eckardt
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
- Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Anthony J. Bleyer
- Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, NC 27101
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, 128 08 Prague, Czech Republic
| | - Anna Köttgen
- Institute of Genetic Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, D-79106 Freiburg, Germany
- Centre for Integrative Biological Signalling Studies, University of Freiburg, D-79106 Freiburg, Germany
| | - Peter J. Conlon
- Division of Nephrology, Beaumont General Hospital, 1297 Dublin, Ireland
- Department of Medicine, Royal College of Surgeons in Ireland, 1297 Dublin, Ireland
| | - Michael Wiesener
- Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - John A. Sayer
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE1 3BZ, United Kingdom
- Renal Services, Newcastle Upon Tyne Hospitals National Health Service Trust, Newcastle upon Tyne NE7 7DN, United Kingdom
- National Institute for Health and Care Research (NIHR) Newcastle Biomedical Research Centre, Newcastle upon Tyne NE4 5PL, United Kingdom
| | - Luca Rampoldi
- Molecular Genetics of Renal Disorders, Division of Genetics and Cell Biology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale San Raffaele, Milan, 20132 Italy
| | - Olivier Devuyst
- Institute of Physiology, University of Zurich, CH-8057 Zurich, Switzerland
- Division of Nephrology, Cliniques Universitaires Saint-Luc, 1200 Brussels, Belgium
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Utami SB, Endo R, Hamada T, Notsu T, Minato H, Komatsu K, Nakayama Y, Shirayoshi Y, Yamamoto K, Okada S, Ninomiya H, Otuki A, Hisatome I. Hsp70 promotes maturation of uromodulin mutants that cause familial juvenile hyperuricemic nephropathy and suppresses cellular damage. Clin Exp Nephrol 2022; 26:522-529. [PMID: 35212881 DOI: 10.1007/s10157-022-02196-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/04/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Familial juvenile hyperuricemic nephropathy (FJHN) is an autosomal dominant disorder caused by mutations in UMOD. Here we studied effects of genetic expression and pharmacological induction of Hsp70 on the UMOD mutants C112Y and C217G. METHODS We expressed wild type (WT), C112Y and C217G in HEK293 cells and studied their maturation and cellular damage using western blot and flow cytometry. RESULTS Expression of C112Y or C217G increased pro-apoptotic proteins, decreased anti-apoptotic proteins, and induced cellular apoptosis as examined by annexin V staining and flow cytometry. Overexpression of Hsp70 or administration of an Hsp70 inducer geranylgeranylacetone (GGA) promoted maturation of the mutant proteins, increased their secreted forms, normalized the levels of pro- and anti-apoptotic proteins and suppressed apoptosis. CONCLUSION These findings indicated that Hsp70 enhanced maturation of C112Y and C217G and reduced cellular apoptosis, suggesting that Hsp70 induction might be of a therapeutic value for treatment of FJHN.
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Affiliation(s)
- Sulistiyati Bayu Utami
- Department of Genetic Medicine and Regenerative Therapeutics, Faculty of Medicine, Tottori University, Yonago, Japan.,Department of Cardiology and Vascular Medicine, Diponegoro University, Semarang, Indonesia
| | - Ryo Endo
- Department of Anesthesiology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Toshihiro Hamada
- Department of Community-Based Family Medicine, Faculty of Medicine, Tottori University, Yonago, Japan.
| | - Tomomi Notsu
- Department of Genetic Medicine and Regenerative Therapeutics, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Hiroyuki Minato
- Department of Anesthesiology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Koji Komatsu
- Department of Psychiatry, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Yuji Nakayama
- Research Center for Bioscience and Technology, Tottori University, Yonago, Japan
| | - Yasuaki Shirayoshi
- Department of Genetic Medicine and Regenerative Therapeutics, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Kazuhiro Yamamoto
- Division of Cardiovascular Medicine, Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University, Yonago, 683-8503, Japan
| | - Shinichi Okada
- Department of Pediatrics, Yonago Medical Center, Yonago, Japan
| | - Haruaki Ninomiya
- Department of Biological Regulation, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Akihiro Otuki
- Department of Anesthesiology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Ichiro Hisatome
- Department of Genetic Medicine and Regenerative Therapeutics, Faculty of Medicine, Tottori University, Yonago, Japan.,Department of Cardiovascular Medicine, Yonago Medical Center, Yonago, Japan
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Hepsin-mediated Processing of Uromodulin is Crucial for Salt-sensitivity and Thick Ascending Limb Homeostasis. Sci Rep 2019; 9:12287. [PMID: 31444371 PMCID: PMC6707305 DOI: 10.1038/s41598-019-48300-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/13/2019] [Indexed: 12/27/2022] Open
Abstract
Uromodulin is a zona pellucida-type protein essentially produced in the thick ascending limb (TAL) of the mammalian kidney. It is the most abundant protein in normal urine. Defective uromodulin processing is associated with various kidney disorders. The luminal release and subsequent polymerization of uromodulin depend on its cleavage mediated by the serine protease hepsin. The biological relevance of a proper cleavage of uromodulin remains unknown. Here we combined in vivo testing on hepsin-deficient mice, ex vivo analyses on isolated tubules and in vitro studies on TAL cells to demonstrate that hepsin influence on uromodulin processing is an important modulator of salt transport via the sodium cotransporter NKCC2 in the TAL. At baseline, hepsin-deficient mice accumulate uromodulin, along with hyperactivated NKCC2, resulting in a positive sodium balance and a better adaptation to water deprivation. In conditions of high salt intake, defective uromodulin processing predisposes hepsin-deficient mice to a salt-wasting phenotype, with a decreased salt sensitivity. These modifications are associated with intracellular accumulation of uromodulin, endoplasmic reticulum-stress and signs of tubular damage. These studies expand the physiological role of hepsin and uromodulin and highlight the importance of hepsin-mediated processing of uromodulin for kidney tubule homeostasis and salt sensitivity.
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Glycosyl-Phosphatidylinositol-Anchored Anti-HIV Env Single-Chain Variable Fragments Interfere with HIV-1 Env Processing and Viral Infectivity. J Virol 2018; 92:JVI.02080-17. [PMID: 29321330 DOI: 10.1128/jvi.02080-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/02/2018] [Indexed: 11/20/2022] Open
Abstract
In previous studies, we demonstrated that single-chain variable fragments (scFvs) from anti-human immunodeficiency virus (HIV) Env monoclonal antibodies act as entry inhibitors when tethered to the surface of target cells by a glycosyl-phosphatidylinositol (GPI) anchor. Interestingly, even if a virus escapes inhibition at entry, its replication is ultimately controlled. We hypothesized that in addition to functioning as entry inhibitors, anti-HIV GPI-scFvs may also interact with Env in an infected cell, thereby interfering with the infectivity of newly produced virions. Here, we show that expression of the anti-HIV Env GPI-scFvs in virus-producing cells reduced the release of HIV from cells 5- to 22-fold, and infectivity of the virions that were released was inhibited by 74% to 99%. Additionally, anti-HIV Env GPI-scFv X5 inhibited virion production and infectivity after latency reactivation and blocked transmitter/founder virus production and infectivity in primary CD4+ T cells. In contrast, simian immunodeficiency virus (SIV) production and infectivity were not affected by the anti-HIV Env GPI-scFvs. Loss of infectivity of HIV was associated with a reduction in the amount of virion-associated Env gp120. Interestingly, an analysis of Env expression in cell lysates demonstrated that the anti-Env GPI-scFvs interfered with processing of Env gp160 precursors in cells. These data indicate that GPI-scFvs can inhibit Env processing and function, thereby restricting production and infectivity of newly synthesized HIV. Anti-Env GPI-scFvs therefore appear to be unique anti-HIV molecules as they derive their potent inhibitory activity by interfering with both early (receptor binding/entry) and late (Env processing and incorporation into virions) stages of the HIV life cycle.IMPORTANCE The restoration of immune function and persistence of CD4+ T cells in HIV-1-infected individuals without antiretroviral therapy requires a way to increase resistance of CD4+ T cells to infection by both R5- and X4-tropic HIV-1. Previously, we reported that anchoring anti-HIV-1 single-chain variable fragments (scFvs) via glycosyl-phosphatidylinositol (GPI) to the surface of permissive cells conferred a high level of resistance to HIV-1 variants at the level of entry. Here, we report that anti-HIV GPI-scFvs also derive their potent antiviral activity in part by blocking HIV production and Env processing, which consequently inhibits viral infectivity even in primary infection models. Thus, we conclude that GPI-anchored anti-HIV scFvs derive their potent blocking activity of HIV replication by interfering with successive stages of the viral life cycle. They may be effectively used in genetic intervention of HIV-1 infection.
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Liu Y, Goldfarb DS, El-Achkar TM, Lieske JC, Wu XR. Tamm-Horsfall protein/uromodulin deficiency elicits tubular compensatory responses leading to hypertension and hyperuricemia. Am J Physiol Renal Physiol 2018; 314:F1062-F1076. [PMID: 29357410 DOI: 10.1152/ajprenal.00233.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Expression of Tamm-Horsfall protein (THP or uromodulin) is highly restricted to the kidney thick ascending limb (TAL) of loop of Henle. Despite the unique location and recent association of THP gene mutations with hereditary uromodulin-associated kidney disease and THP single nucleotide polymorphisms with chronic kidney disease and hypertension, the physiological function(s) of THP and its pathological involvement remain incompletely understood. By studying age-dependent changes of THP knockout (KO) mice, we show here that young KO mice had significant salt and water wasting but were partially responsive to furosemide, due to decreased luminal translocation of Na-K-Cl cotransporter 2 (NKCC2) in the TAL. Aged THP KO mice were, however, markedly oliguric and unresponsive to furosemide, and their NKCC2 was localized primarily in the cytoplasm as evidenced by lipid raft floatation assay, cell fractionation, and confocal and immunoelectron microscopy. These aged KO mice responded to metolazone and acetazolamide, known to target distal and proximal tubules, respectively. They also had marked upregulation of renin in juxtaglomerular apparatus and serum, and they were hypertensive. Finally, the aged THP KO mice had significant upregulation of Na-coupled urate transporters Slc5a8 and Slc22a12 as well as sodium-hydrogen exchanger 3 (NHE3) in the proximal tubule and elevated serum uric acid and allantoin. Collectively, our results suggest that THP deficiency can cause progressive disturbances in renal functions via initially NKCC2 dysfunction and later compensatory responses, resulting in prolonged activation of the renin-angiotensin-aldosterone axis and hyperuricemia.
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Affiliation(s)
- Yan Liu
- Department of Urology, New York University School of Medicine , New York, New York
| | - David S Goldfarb
- Department of Nephrology, New York University School of Medicine , New York, New York.,Veterans Affairs New York Harbor Healthcare System, Manhattan Campus, New York, New York
| | - Tarek M El-Achkar
- Division of Nephrology, Indiana University School of Medicine and Indianapolis Veterans Affairs , Indianapolis, Indiana
| | - John C Lieske
- Division of Nephrology and Hypertension, Mayo Clinic , Rochester, Minnesota
| | - Xue-Ru Wu
- Department of Urology, New York University School of Medicine , New York, New York.,Veterans Affairs New York Harbor Healthcare System, Manhattan Campus, New York, New York.,Department of Pathology, New York University School of Medicine , New York, New York
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7
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Devuyst O, Olinger E, Rampoldi L. Uromodulin: from physiology to rare and complex kidney disorders. Nat Rev Nephrol 2017; 13:525-544. [PMID: 28781372 DOI: 10.1038/nrneph.2017.101] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Uromodulin (also known as Tamm-Horsfall protein) is exclusively produced in the kidney and is the most abundant protein in normal urine. The function of uromodulin remains elusive, but the available data suggest that this protein might regulate salt transport, protect against urinary tract infection and kidney stones, and have roles in kidney injury and innate immunity. Interest in uromodulin was boosted by genetic studies that reported involvement of the UMOD gene, which encodes uromodulin, in a spectrum of rare and common kidney diseases. Rare mutations in UMOD cause autosomal dominant tubulointerstitial kidney disease (ADTKD), which leads to chronic kidney disease (CKD). Moreover, genome-wide association studies have identified common variants in UMOD that are strongly associated with risk of CKD and also with hypertension and kidney stones in the general population. These findings have opened up a new field of kidney research. In this Review we summarize biochemical, physiological, genetic and pathological insights into the roles of uromodulin; the mechanisms by which UMOD mutations cause ADTKD, and the association of common UMOD variants with complex disorders.
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Affiliation(s)
- Olivier Devuyst
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Eric Olinger
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Luca Rampoldi
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, Via Olgettina 58, 20132 Milan, Italy
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Rysz J, Gluba-Brzózka A, Franczyk B, Jabłonowski Z, Ciałkowska-Rysz A. Novel Biomarkers in the Diagnosis of Chronic Kidney Disease and the Prediction of Its Outcome. Int J Mol Sci 2017; 18:E1702. [PMID: 28777303 PMCID: PMC5578092 DOI: 10.3390/ijms18081702] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/17/2017] [Accepted: 07/26/2017] [Indexed: 02/07/2023] Open
Abstract
In its early stages, symptoms of chronic kidney disease (CKD) are usually not apparent. Significant reduction of the kidney function is the first obvious sign of disease. If diagnosed early (stages 1 to 3), the progression of CKD can be altered and complications reduced. In stages 4 and 5 extensive kidney damage is observed, which usually results in end-stage renal failure. Currently, the diagnosis of CKD is made usually on the levels of blood urea and serum creatinine (sCr), however, sCr has been shown to be lacking high predictive value. Due to the development of genomics, epigenetics, transcriptomics, proteomics, and metabolomics, the introduction of novel techniques will allow for the identification of novel biomarkers in renal diseases. This review presents some new possible biomarkers in the diagnosis of CKD and in the prediction of outcome, including asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), uromodulin, kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), miRNA, ncRNA, and lincRNA biomarkers and proteomic and metabolomic biomarkers. Complicated pathomechanisms of CKD development and progression require not a single marker but their combination in order to mirror all types of alterations occurring in the course of this disease. It seems that in the not so distant future, conventional markers may be exchanged for new ones, however, confirmation of their efficacy, sensitivity and specificity as well as the reduction of analysis costs are required.
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Affiliation(s)
- Jacek Rysz
- Department of Nephrology, Hypertension and Family Medicine, Medical University of Lodz, Zeromskiego 113, 90-549 Lodz, Poland.
| | - Anna Gluba-Brzózka
- Department of Nephrology, Hypertension and Family Medicine, WAM Teaching Hospital, Zeromskiego 113, 90-549 Lodz, Poland.
| | - Beata Franczyk
- Department of Nephrology, Hypertension and Family Medicine, Medical University of Lodz, Zeromskiego 113, 90-549 Lodz, Poland.
| | - Zbigniew Jabłonowski
- I Department of Urology, Medical University of Lodz, Zeromskiego 113, 90-549 Lodz, Poland.
| | - Aleksandra Ciałkowska-Rysz
- Palliative Medicine Unit, Chair of Oncology, Medical University of Lodz, Zeromskiego 113, 90-549 Lodz, Poland.
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Leiherer A, Muendlein A, Saely CH, Kinz E, Brandtner EM, Fraunberger P, Drexel H. Serum uromodulin is associated with impaired glucose metabolism. Medicine (Baltimore) 2017; 96:e5798. [PMID: 28151855 PMCID: PMC5293418 DOI: 10.1097/md.0000000000005798] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/06/2016] [Accepted: 12/12/2016] [Indexed: 02/04/2023] Open
Abstract
Uromodulin is the most abundant urine protein under physiological conditions. It has recently been described as a serum and plasma marker for kidney disease. Whether uromodulin is associated with impaired glucose metabolism is unknown.We therefore measured serum uromodulin and glucose traits in a cohort of 529 consecutively recruited patients.Serum uromodulin was significantly and inversely correlated with fasting plasma glucose (r = -0.161; P < 0.001), with plasma glucose 2 hours after an oral 75 g glucose challenge (r = -0.158; P = 0.001), and with HbA1c (r = -0.103; P = 0.018). A total of 146 (27.6%) of our patients had type 2 diabetes mellitus (T2DM). Analysis of covariance confirmed that T2DM was an independent determinant of serum uromodulin (F = 5.5, P = 0.020) after multivariate adjustment including hypertension and glomerular filtration rate. Prospectively, uromodulin was lowest in patients with T2DM at baseline, higher in initially nondiabetic subjects who developed diabetes during follow-up (FU) and highest among nondiabetic patients (147.7 ± 69.9 vs 164 ± 67 vs 179.9 ± 82.2 ng/mL, Ptrend < 0.001). Similar results were seen with respect to prediabetes (168.0 ± 81.2 vs 172.8 ± 66.3 vs 188.2 ± 74.0 ng/mL, P = 0.011).We conclude that serum uromodulin is significantly associated with impaired glucose metabolism and the development of prediabetes and diabetes.
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Affiliation(s)
- Andreas Leiherer
- Vorarlberg Institute for Vascular Investigation and Treatment (VIVIT), Feldkirch, Austria
- Private University of the Principality of Liechtenstein, Triesen, Liechtenstein
- Medical Central Laboratories, Academic Teaching Hospital Feldkirch, Feldkirch, Austria
| | - Axel Muendlein
- Vorarlberg Institute for Vascular Investigation and Treatment (VIVIT), Feldkirch, Austria
- Private University of the Principality of Liechtenstein, Triesen, Liechtenstein
| | - Christoph H. Saely
- Vorarlberg Institute for Vascular Investigation and Treatment (VIVIT), Feldkirch, Austria
- Private University of the Principality of Liechtenstein, Triesen, Liechtenstein
- Department of Medicine and Cardiology, Academic Teaching Hospital Feldkirch, Feldkirch, Austria
| | - Elena Kinz
- Vorarlberg Institute for Vascular Investigation and Treatment (VIVIT), Feldkirch, Austria
| | - Eva M. Brandtner
- Vorarlberg Institute for Vascular Investigation and Treatment (VIVIT), Feldkirch, Austria
| | - Peter Fraunberger
- Private University of the Principality of Liechtenstein, Triesen, Liechtenstein
- Medical Central Laboratories, Academic Teaching Hospital Feldkirch, Feldkirch, Austria
| | - Heinz Drexel
- Vorarlberg Institute for Vascular Investigation and Treatment (VIVIT), Feldkirch, Austria
- Private University of the Principality of Liechtenstein, Triesen, Liechtenstein
- Department of Medicine and Cardiology, Academic Teaching Hospital Feldkirch, Feldkirch, Austria
- Drexel University College of Medicine, Philadelphia, PA, USA
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Steubl D, Block M, Herbst V, Nockher WA, Schlumberger W, Satanovskij R, Angermann S, Hasenau AL, Stecher L, Heemann U, Renders L, Scherberich J. Plasma Uromodulin Correlates With Kidney Function and Identifies Early Stages in Chronic Kidney Disease Patients. Medicine (Baltimore) 2016; 95:e3011. [PMID: 26962815 PMCID: PMC4998896 DOI: 10.1097/md.0000000000003011] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 01/27/2016] [Accepted: 02/09/2016] [Indexed: 01/07/2023] Open
Abstract
Uromodulin, released from tubular cells of the ascending limb into the blood, may be associated with kidney function. This work studies the relevance of plasma uromodulin as a biomarker for kidney function in an observational cohort of chronic kidney disease (CKD) patients and subjects without CKD (CKD stage 0). It should be further evaluated if uromodulin allows the identification of early CKD stages.Plasma uromodulin, serum creatinine, cystatin C, blood-urea-nitrogen (BUN) concentrations, and estimated glomerular filtration rate (eGFR CKD-EPIcrea-cystatin) were assessed in 426 individuals of whom 71 were CKD stage 0 and 355 had CKD. Besides descriptive statistics, univariate correlations between uromodulin and biomarkers/eGFR were calculated using Pearson-correlation coefficient. Multiple linear regression modeling was applied to establish the association between uromodulin and eGFR adjusted for demographic parameters and pharmacologic treatment. Receiver-operating-characteristic (ROC) analysis adjusted for demographic parameters was performed to test if uromodulin allows differentiation of subjects with CKD stage 0 and CKD stage I.Mean uromodulin plasma levels were 85.7 ± 60.5 ng/mL for all CKD stages combined. Uromodulin was correlated with all biomarkers/eGFR in univariate analysis (eGFR: r = 0.80, creatinine: r = -0.76, BUN: r = -0.72, and cystatin C: r = -0.79). Multiple linear regression modeling showed significant association between uromodulin and eGFR (coefficient estimate β = 0.696, 95% confidence interval [CI] 0.603-0.719, P < 0.001). In ROC analysis uromodulin was the only parameter that significantly improved a model containing demographic parameters to differentiate between CKD 0° and I° (area under the curve [AUC] 0.831, 95% CI 0.746-0.915, P = 0.008) compared to creatinine, cystatin C, BUN, and eGFR (AUC for creatinine: 0.722, P = 0.056, cystatin C: 0.668, P = 0.418, BUN: 0.653, P = 0.811, and eGFR: 0.634, P = 0.823).Plasma uromodulin serves as a robust biomarker for kidney function and uniquely allows the identification of early stages of CKD. As a marker of tubular secretion it might represent remaining nephron mass and therefore intrinsic "kidney function" rather than just glomerular filtration, the latter only being of limited value to represent kidney function as a whole. It therefore gives substantial information on the renal situation in addition to glomerular filtration and potentially solves the problem of creatinine-blind range of CKD, in which kidney impairment often remains undetected.
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Affiliation(s)
- Dominik Steubl
- From the Abteilung für Nephrologie (DS, RS, SA, ALH, UH, LR), Klinikum rechts der Isar, Technische Universität München, Munich, Germany; Euroimmun Medizinische Labordiagnostika AG (MB, VH, WS), Lübeck, Germany; Institut für Laboratoriumsmedizin und Pathobiochemie (WAN), Molekulare Diagnostik, Universitätsklinikum Marburg, Philipps-Universität Marburg, Marburg, Germany; Institut für medizinische Statistik und Epidemiologie (LS), Klinikum rechts der Isar, Technische Universität München, Munich, Germany; and Klinikum München-Harlaching (JS), Teaching Hospital of the Ludwig-Maximilians-Universität, Munich, Germany
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Padmanabhan S, Graham L, Ferreri NR, Graham D, McBride M, Dominiczak AF. Uromodulin, an Emerging Novel Pathway for Blood Pressure Regulation and Hypertension. Hypertension 2014; 64:918-23. [DOI: 10.1161/hypertensionaha.114.03132] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Sandosh Padmanabhan
- From the BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (S.P., L.G., D.G., M.M., A.F.D.); and Department of Pharmacology, New York Medical College, Valhalla (N.R.F.)
| | - Lesley Graham
- From the BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (S.P., L.G., D.G., M.M., A.F.D.); and Department of Pharmacology, New York Medical College, Valhalla (N.R.F.)
| | - Nicholas R. Ferreri
- From the BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (S.P., L.G., D.G., M.M., A.F.D.); and Department of Pharmacology, New York Medical College, Valhalla (N.R.F.)
| | - Delyth Graham
- From the BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (S.P., L.G., D.G., M.M., A.F.D.); and Department of Pharmacology, New York Medical College, Valhalla (N.R.F.)
| | - Martin McBride
- From the BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (S.P., L.G., D.G., M.M., A.F.D.); and Department of Pharmacology, New York Medical College, Valhalla (N.R.F.)
| | - Anna F. Dominiczak
- From the BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (S.P., L.G., D.G., M.M., A.F.D.); and Department of Pharmacology, New York Medical College, Valhalla (N.R.F.)
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Dinour D, Ganon L, Nomy LI, Ron R, Holtzman EJ. Wild-type uromodulin prevents NFkB activation in kidney cells, while mutant uromodulin, causing FJHU nephropathy, does not. J Nephrol 2014; 27:257-64. [PMID: 24648000 DOI: 10.1007/s40620-014-0079-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 01/22/2014] [Indexed: 02/02/2023]
Abstract
BACKGROUND Uromodulin (Tamm-Horsfall protein) is the most abundant urinary protein in healthy individuals. Despite 60 years of research, its physiological role remains rather elusive. Familial juvenile hyperuricemic nephropathy and medullary cystic kidney disease Type 2 are autosomal dominant tubulointerstitial nephropathies characterized by gouty arthritis and progressive renal insufficiency, caused by uromodulin (UMOD) mutations. The aim of this study was to compare the cellular effects of mutant and wild-type UMOD. METHODS Wild-type UMOD cDNA was cloned from human kidney cDNA into pcDNA3 expression vector. A mutant UMOD construct, containing the previously reported mutation, V273, was created by in vitro mutagenesis. Transient and stable transfection studies were performed in human embryonic kidney cells and mouse distal convoluted tubular cells, respectively. Expression was evaluated by reverse transcription polymerase chain reaction (RT-PCR), western blot and immunofluorescence. Oligosaccharide cleavage by glycosidases was performed to characterize different forms of UMOD. Nuclear translocation of P65 and degradation of IκBα and IRAK1 in response to interleukin (IL)-1β were used to evaluate the effects of wild-type and mutant UMOD on the IL-1R-NFκB pathway. RESULTS The mutant protein was shown to be retained in the endoplasmic reticulum and was not excreted to the cell medium, as opposed to the wild-type protein. NFκB activation in cells expressing mutant UMOD was similar to that of untransfected cells. In contrast, cells over-expressing wild-type UMOD showed markedly reduced NFκB activation. CONCLUSION Our findings suggest that UMOD may have a physiologic function related to its inhibitory effect on the NFκB pathway.
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Affiliation(s)
- Dganit Dinour
- Department of Nephrology and Hypertension, The Chaim Sheba Medical Center, Tel-Hashomer and the Faculty of Medicine, Sackler School of Medicine, Sheba Medical Center, 52621, Tel-Aviv, Israel,
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Common genetic variants of the human uromodulin gene regulate transcription and predict plasma uric acid levels. Kidney Int 2013; 83:733-40. [PMID: 23344472 DOI: 10.1038/ki.2012.449] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Uromodulin (UMOD) genetic variants cause familial juvenile hyperuricemic nephropathy, characterized by hyperuricemia with decreased renal excretion of UMOD and uric acid, suggesting a role for UMOD in the regulation of plasma uric acid. To determine this, we screened common variants across the UMOD locus in one community-based Chinese population of 1000 individuals and the other population from 642 American twins and siblings of European and Hispanic ancestry. Transcriptional activity of promoter variants was estimated in luciferase reporter plasmids transfected into HEK-293 cells and mIMCD3 cells. In the primary Chinese population, we found that carriers of the GCC haplotype had higher plasma uric acid, and three promoter variants were associated with plasma uric acid. UMOD promoter variants displayed reciprocal effects on urine uric acid excretion and plasma uric acid concentration, suggesting a primary effect on renal tubular handling of urate. These UMOD genetic marker-on-trait associations for uric acid were replicated in the independent American cohort. Site-directed mutagenesis at trait-associated UMOD promoter variants altered promoter activity in transfected luciferase reporter plasmids. Thus, UMOD promoter variants seem to initiate a cascade of transcriptional and biochemical changes influencing UMOD secretion, leading to altered plasma uric acid levels.
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Han J, Chen Y, Liu Y, Liang Y, Wang X, Liu L, Wang F, Zhang L, Zhang H, Wang H. Common variants of the UMOD promoter associated with blood pressure in a community-based Chinese cohort. Hypertens Res 2012; 35:769-74. [DOI: 10.1038/hr.2012.51] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Spencer JD, Hains DS, Porter E, Bevins CL, DiRosario J, Becknell B, Wang H, Schwaderer AL. Human alpha defensin 5 expression in the human kidney and urinary tract. PLoS One 2012; 7:e31712. [PMID: 22359618 PMCID: PMC3281003 DOI: 10.1371/journal.pone.0031712] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 01/11/2012] [Indexed: 11/18/2022] Open
Abstract
Background The mechanisms that maintain sterility in the urinary tract are incompletely understood. Recent studies have implicated the importance of antimicrobial peptides (AMP) in protecting the urinary tract from infection. Here, we characterize the expression and relevance of the AMP human alpha-defensin 5 (HD5) in the human kidney and urinary tract in normal and infected subjects. Methodology/Principal Findings Using RNA isolated from human kidney, ureter, and bladder tissue, we performed quantitative real-time PCR to show that DEFA5, the gene encoding HD5, is constitutively expressed throughout the urinary tract. With pyelonephritis, DEFA5 expression significantly increased in the kidney. Using immunoblot analysis, HD5 production also increased with pyelonephritis. Immunostaining localized HD5 to the urothelium of the bladder and ureter. In the kidney, HD5 was primarily produced in the distal nephron and collecting tubules. Using immunoblot and ELISA assays, HD5 was not routinely detected in non-infected human urine samples while mean urinary HD5 production increased with E.coli urinary tract infection. Conclusions/Significance DEFA5 is expressed throughout the urinary tract in non-infected subjects. Specifically, HD5 is expressed throughout the urothelium of the lower urinary tract and in the collecting tubules of the kidney. With infection, HD5 expression increases in the kidney and levels become detectable in the urine. To our knowledge, our findings represent the first to quantitate HD5 expression and production in the human kidney. Moreover, this is the first report to detect the presence of HD5 in infected urine samples. Our results suggest that HD5 may have an important role in maintaining urinary tract sterility.
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Affiliation(s)
- John David Spencer
- Pediatric Nephrology Fellowship Program, Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Division of Nephrology, Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - David S. Hains
- Division of Nephrology, Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Edith Porter
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, California, United States of America
| | - Charles L. Bevins
- Department of Microbiology and Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Julianne DiRosario
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Brian Becknell
- Pediatric Nephrology Fellowship Program, Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Division of Nephrology, Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Huanyu Wang
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Andrew L. Schwaderer
- Division of Nephrology, Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- * E-mail:
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OIT3 deficiency impairs uric acid reabsorption in renal tubule. FEBS Lett 2012; 586:760-5. [DOI: 10.1016/j.febslet.2012.01.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 01/20/2012] [Accepted: 01/21/2012] [Indexed: 11/20/2022]
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Ma L, Liu Y, El-Achkar TM, Wu XR. Molecular and cellular effects of Tamm-Horsfall protein mutations and their rescue by chemical chaperones. J Biol Chem 2011; 287:1290-305. [PMID: 22117067 DOI: 10.1074/jbc.m111.283036] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Correct folding of a nascent polypeptide in the lumen of the endoplasmic reticulum (ER) into a three-dimensional conformation is a crucial step in the stability, intracellular trafficking, and targeting to the final destination of a protein. By transiently and stably expressing human-relevant mutants of Tamm-Horsfall protein in polarized Madin-Darby canine kidney cells, we show here that a cysteine-altering mutation in the evolutionally conserved cysteine-rich domain had more severe defects in ER exit and surface translocation and triggered more apoptosis than a cysteine-altering mutation outside the domain. Both mutants were able to specifically bind and trap the wild-type Tamm-Horsfall protein (THP) and prevent it from exiting the ER and translocating to the cell surface. This explains at least partly why in patients with THP-associated diseases there is a marked urinary reduction of both the mutant and the wild-type THP. Exposure of mutant-expressing cells to low temperature (30 °C), osmolytes (glycerol, trimethylamine N-oxide, and dimethyl sulfoxide), and the Ca(2+)-ATP inhibitor thapsigargin only slightly relieved ER retention and increased surface targeting of the mutants. In contrast, sodium 4-phenylbutyrate and probenecid, the latter a uricosuric drug used clinically to treat gout, markedly reduced ER retention of the mutants and increased their surface translocation and secretion into the culture media. The rescue of the THP mutants was associated with the restoration of the level and subcellular localization of cytosolic chaperone HSP70. Our results reveal intricate mechanistic details that may underlie THP-associated diseases and suggest that novel therapeutics enhancing the refolding of THP mutants may be of important value in therapy.
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Affiliation(s)
- Lijie Ma
- Department of Urology, New York University School of Medicine, New York, New York 10016, USA
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Mutig K, Kahl T, Saritas T, Godes M, Persson P, Bates J, Raffi H, Rampoldi L, Uchida S, Hille C, Dosche C, Kumar S, Castañeda-Bueno M, Gamba G, Bachmann S. Activation of the bumetanide-sensitive Na+,K+,2Cl- cotransporter (NKCC2) is facilitated by Tamm-Horsfall protein in a chloride-sensitive manner. J Biol Chem 2011; 286:30200-10. [PMID: 21737451 DOI: 10.1074/jbc.m111.222968] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Active transport of NaCl across thick ascending limb (TAL) epithelium is accomplished by Na(+),K(+),2Cl(-) cotransporter (NKCC2). The activity of NKCC2 is determined by vasopressin (AVP) or intracellular chloride concentration and includes its amino-terminal phosphorylation. Co-expressed Tamm-Horsfall protein (THP) has been proposed to interact with NKCC2. We hypothesized that THP modulates NKCC2 activity in TAL. THP-deficient mice (THP(-/-)) showed an increased abundance of intracellular NKCC2 located in subapical vesicles (+47% compared with wild type (WT) mice), whereas base-line phosphorylation of NKCC2 was significantly decreased (-49% compared with WT mice), suggesting reduced activity of the transporter in the absence of THP. Cultured TAL cells with low endogenous THP levels and low base-line phosphorylation of NKCC2 displayed sharp increases in NKCC2 phosphorylation (+38%) along with a significant change of intracellular chloride concentration upon transfection with THP. In NKCC2-expressing frog oocytes, co-injection with THP cRNA significantly enhanced the activation of NKCC2 under low chloride hypotonic stress (+112% versus +235%). Short term (30 min) stimulation of the vasopressin V2 receptor pathway by V2 receptor agonist (deamino-cis-D-Arg vasopressin) resulted in enhanced NKCC2 phosphorylation in WT mice and cultured TAL cells transfected with THP, whereas in the absence of THP, NKCC2 phosphorylation upon deamino-cis-D-Arg vasopressin was blunted in both systems. Attenuated effects of furosemide along with functional and structural adaptation of the distal convoluted tubule in THP(-/-) mice supported the notion that NaCl reabsorption was impaired in TAL lacking THP. In summary, these results are compatible with a permissive role for THP in the modulation of NKCC2-dependent TAL salt reabsorptive function.
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Affiliation(s)
- Kerim Mutig
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Renigunta A, Renigunta V, Saritas T, Decher N, Mutig K, Waldegger S. Tamm-Horsfall glycoprotein interacts with renal outer medullary potassium channel ROMK2 and regulates its function. J Biol Chem 2011; 286:2224-2235. [PMID: 21081491 PMCID: PMC3023518 DOI: 10.1074/jbc.m110.149880] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 10/27/2010] [Indexed: 09/12/2023] Open
Abstract
Tamm-Horsfall glycoprotein (THGP) or Uromodulin is a membrane protein exclusively expressed along the thick ascending limb (TAL) and early distal convoluted tubule (DCT) of the nephron. Mutations in the THGP encoding gene result in Familial Juvenile Hyperuricemic Nephropathy (FJHN), Medullary Cystic Kidney Disease type 2 (MCKD-2), and Glomerulocystic Kidney Disease (GCKD). The physicochemical and biological properties of THGP have been studied extensively, but its physiological function in the TAL remains obscure. We performed yeast two-hybrid screening employing a human kidney cDNA library and identified THGP as a potential interaction partner of the renal outer medullary potassium channel (ROMK2), a key player in the process of salt reabsorption along the TAL. Functional analysis by electrophysiological techniques in Xenopus oocytes showed a strong increase in ROMK current amplitudes when co-expressed with THGP. The effect of THGP was specific for ROMK2 and did not influence current amplitudes upon co-expression with Kir2.x, inward rectifier potassium channels related to ROMK. Single channel conductance and open probability of ROMK2 were not altered by co-expression of THGP, which instead increased surface expression of ROMK2 as determined by patch clamp analysis and luminometric surface quantification, respectively. Despite preserved interaction with ROMK2, disease-causing THGP mutants failed to increase its current amplitude and surface expression. THGP(-/-) mice exhibited increased ROMK accumulation in intracellular vesicular compartments when compared with WT animals. Therefore, THGP modulation of ROMK function confers a new role of THGP on renal ion transport and may contribute to salt wasting observed in FJHN/MCKD-2/GCKD patients.
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Affiliation(s)
- Aparna Renigunta
- From the Department of Pediatric Nephrology, Children's Hospital, Philipps University of Marburg, Baldingerstr., 35043 Marburg, Germany
| | - Vijay Renigunta
- the Institute of Physiology, Philipps University of Marburg, Deutschhausstr. 2, 35037 Marburg, Germany, and
| | - Turgay Saritas
- the Institute of Anatomy, Charité-University Medicine, Philippstr. 12, Berlin, Germany
| | - Niels Decher
- the Institute of Physiology, Philipps University of Marburg, Deutschhausstr. 2, 35037 Marburg, Germany, and
| | - Kerim Mutig
- the Institute of Anatomy, Charité-University Medicine, Philippstr. 12, Berlin, Germany
| | - Siegfried Waldegger
- From the Department of Pediatric Nephrology, Children's Hospital, Philipps University of Marburg, Baldingerstr., 35043 Marburg, Germany
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Abstract
Autosomal-dominant interstitial kidney disease is characterized by slow progression of chronic kidney disease in patients with bland urinary sediment and no or low-grade proteinuria. There are at least three subtypes. Patients with mutations in the UMOD gene encoding uromodulin suffer from precocious gout in addition to chronic kidney failure. Diagnosis can be achieved through genetic analysis of the UMOD gene. Patients with mutations in the REN gene encoding renin suffer from anemia in childhood, hyperuricemia, mild hyperkalemia, and progressive kidney disease. Genetic analysis of the REN gene can be performed to diagnose affected individuals. There is a third form of inherited interstitial kidney disease for which the cause has not been found. These individuals suffer from chronic kidney disease with no other identified clinical signs. Linkage to chromosome 1 has been identified in a number of these families. Proper diagnosis is valuable not only to the affected individual but also to the entire family and can facilitate treatment, transplantation, and research efforts.
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Affiliation(s)
- Anthony J Bleyer
- Section on Nephrology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Padmanabhan S, Melander O, Johnson T, Di Blasio AM, Lee WK, Gentilini D, Hastie CE, Menni C, Monti MC, Delles C, Laing S, Corso B, Navis G, Kwakernaak AJ, van der Harst P, Bochud M, Maillard M, Burnier M, Hedner T, Kjeldsen S, Wahlstrand B, Sjögren M, Fava C, Montagnana M, Danese E, Torffvit O, Hedblad B, Snieder H, Connell JMC, Brown M, Samani NJ, Farrall M, Cesana G, Mancia G, Signorini S, Grassi G, Eyheramendy S, Wichmann HE, Laan M, Strachan DP, Sever P, Shields DC, Stanton A, Vollenweider P, Teumer A, Völzke H, Rettig R, Newton-Cheh C, Arora P, Zhang F, Soranzo N, Spector TD, Lucas G, Kathiresan S, Siscovick DS, Luan J, Loos RJF, Wareham NJ, Penninx BW, Nolte IM, McBride M, Miller WH, Nicklin SA, Baker AH, Graham D, McDonald RA, Pell JP, Sattar N, Welsh P, Munroe P, Caulfield MJ, Zanchetti A, Dominiczak AF. Genome-wide association study of blood pressure extremes identifies variant near UMOD associated with hypertension. PLoS Genet 2010; 6:e1001177. [PMID: 21082022 PMCID: PMC2965757 DOI: 10.1371/journal.pgen.1001177] [Citation(s) in RCA: 258] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 09/23/2010] [Indexed: 12/19/2022] Open
Abstract
Hypertension is a heritable and major contributor to the global burden of disease. The sum of rare and common genetic variants robustly identified so far explain only 1%–2% of the population variation in BP and hypertension. This suggests the existence of more undiscovered common variants. We conducted a genome-wide association study in 1,621 hypertensive cases and 1,699 controls and follow-up validation analyses in 19,845 cases and 16,541 controls using an extreme case-control design. We identified a locus on chromosome 16 in the 5′ region of Uromodulin (UMOD; rs13333226, combined P value of 3.6×10−11). The minor G allele is associated with a lower risk of hypertension (OR [95%CI]: 0.87 [0.84–0.91]), reduced urinary uromodulin excretion, better renal function; and each copy of the G allele is associated with a 7.7% reduction in risk of CVD events after adjusting for age, sex, BMI, and smoking status (H.R. = 0.923, 95% CI 0.860–0.991; p = 0.027). In a subset of 13,446 individuals with estimated glomerular filtration rate (eGFR) measurements, we show that rs13333226 is independently associated with hypertension (unadjusted for eGFR: 0.89 [0.83–0.96], p = 0.004; after eGFR adjustment: 0.89 [0.83–0.96], p = 0.003). In clinical functional studies, we also consistently show the minor G allele is associated with lower urinary uromodulin excretion. The exclusive expression of uromodulin in the thick portion of the ascending limb of Henle suggests a putative role of this variant in hypertension through an effect on sodium homeostasis. The newly discovered UMOD locus for hypertension has the potential to give new insights into the role of uromodulin in BP regulation and to identify novel drugable targets for reducing cardiovascular risk. Hypertension is the leading contributor to global mortality with a global prevalence of 26.4% in 2000, projected to increase to 29.2% by 2025. While 50%–60% of population variation in blood pressure can be attributable to additive genetic factors, all the genetic variants robustly identified so far explain only 1%–2% of the population variance indicating the presence of additional undiscovered risk variants. Using an extreme case-control strategy, we have discovered a SNP in the promoter region of the uromodulin gene (UMOD) to be associated with hypertension (minor allele protective against hypertension). We then validated this association using large-scale population and case-control studies, where similar extreme criteria for selection of cases and controls have been used (21,466 cases and 18,240 controls). As the locus was related to uromodulin, a protein exclusively expressed in the kidneys, we show that the association is independent of renal dysfunction. We also show preliminary evidence that the SNP allele which is protective against hypertension is also protective against cardiovascular events in 26,654 Swedish subjects followed-up for 12 years. The newly discovered UMOD locus for hypertension has the potential to give unique insights into the role of uromodulin in BP regulation and to identify novel drugable targets.
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Affiliation(s)
- Sandosh Padmanabhan
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Olle Melander
- Department of Clinical Sciences, Hypertension and Cardiovascular Diseases, University Hospital Malmö, Lund University, Malmö, Sweden
| | - Toby Johnson
- Clinical Pharmacology and Barts and the London Genome Centre, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London, United Kingdom
| | | | - Wai K. Lee
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | - Claire E. Hastie
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Cristina Menni
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Università Milano-Bicocca, Dipartimento di Medicina Clinica e Prevenzione, Ospedale San Gerardo, Monza, Milano, Italy
| | - Maria Cristina Monti
- Istituto Auxologico Italiano, Milan, Italy
- Department of Health Science, University of Pavia, Pavia, Italy
| | - Christian Delles
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Stewart Laing
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Barbara Corso
- Istituto Auxologico Italiano, Milan, Italy
- Department of Health Science, University of Pavia, Pavia, Italy
| | - Gerjan Navis
- Department of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Arjan J. Kwakernaak
- Department of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Pim van der Harst
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Murielle Bochud
- University Institute of Social and Preventive Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Marc Maillard
- Service of Nephrology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Michel Burnier
- Service of Nephrology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Thomas Hedner
- Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sverre Kjeldsen
- Department of Cardiology, University of Oslo, Ullevaal Hospital, Oslo, Norway
| | - Björn Wahlstrand
- Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Marketa Sjögren
- Department of Clinical Sciences, Hypertension and Cardiovascular Diseases, University Hospital Malmö, Lund University, Malmö, Sweden
| | - Cristiano Fava
- Department of Clinical Sciences, Hypertension and Cardiovascular Diseases, University Hospital Malmö, Lund University, Malmö, Sweden
- Department of Medicine, Section of Internal Medicine C, University of Verona, Verona, Italy
| | - Martina Montagnana
- Department of Clinical Sciences, Hypertension and Cardiovascular Diseases, University Hospital Malmö, Lund University, Malmö, Sweden
- Department of Life and Reproduction Sciences, Section of Clinical Chemistry, University of Verona, Verona, Italy
| | - Elisa Danese
- Department of Clinical Sciences, Hypertension and Cardiovascular Diseases, University Hospital Malmö, Lund University, Malmö, Sweden
- Department of Life and Reproduction Sciences, Section of Clinical Chemistry, University of Verona, Verona, Italy
| | - Ole Torffvit
- Department of Nephrology, Institution of Clinical Sciences, University Hospital of Lund, Lund, Sweden
| | - Bo Hedblad
- Department of Clinical Sciences, Hypertension and Cardiovascular Diseases, University Hospital Malmö, Lund University, Malmö, Sweden
| | - Harold Snieder
- Unit of Genetic Epidemiology and Bioinformatics, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - John M. C. Connell
- College of Medicine, Dentistry and Nursing, Ninewells Hospital, University of Dundee, Dundee, United Kingdom
| | - Morris Brown
- Clinical Pharmacology Unit, University of Cambridge, Addenbrookes Hospital, Cambridge, United Kingdom
| | - Nilesh J. Samani
- Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Leicester, United Kingdom
| | - Martin Farrall
- Department of Cardiovascular Medicine, Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Giancarlo Cesana
- Università Milano-Bicocca, Dipartimento di Medicina Clinica e Prevenzione, Ospedale San Gerardo, Monza, Milano, Italy
| | - Giuseppe Mancia
- Università Milano-Bicocca, Dipartimento di Medicina Clinica e Prevenzione, Ospedale San Gerardo, Monza, Milano, Italy
| | | | - Guido Grassi
- Università Milano-Bicocca, Dipartimento di Medicina Clinica e Prevenzione, Ospedale San Gerardo, Monza, Milano, Italy
| | - Susana Eyheramendy
- Department of Statistics, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - H. Erich Wichmann
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Medical Informatics, Biometry and Epidemiology, Chair of Epidemiology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Maris Laan
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - David P. Strachan
- Division of Community Health Sciences, St George's, University of London, London, United Kingdom
| | - Peter Sever
- International Centre for Circulatory Health National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Denis Colm Shields
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Alice Stanton
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Peter Vollenweider
- Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Alexander Teumer
- Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Henry Völzke
- Institute for Community Medicine, University of Greifswald, Greifswald, Germany
| | - Rainer Rettig
- Institute of Physiology, University of Greifswald, Greifswald, Germany
| | - Christopher Newton-Cheh
- Center for Human Genetic Research and Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts, United States of America
| | - Pankaj Arora
- Center for Human Genetic Research and Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts, United States of America
| | - Feng Zhang
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Nicole Soranzo
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, United Kingdom
| | - Timothy D. Spector
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Gavin Lucas
- Cardiovascular Epidemiology and Genetics Group, Institut Municipal d'Investigacio Medica, Barcelona, Spain
| | - Sekar Kathiresan
- Center for Human Genetic Research and Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts, United States of America
| | - David S. Siscovick
- Cardiovascular Health Research Unit, Departments of Medicine and Epidemiology, University of Washington, Seattle, Washington, United States of America
| | - Jian'an Luan
- MRC Epidemiology Unit, Institute of Metabolic Science, Cambridge, United Kingdom
| | - Ruth J. F. Loos
- MRC Epidemiology Unit, Institute of Metabolic Science, Cambridge, United Kingdom
| | - Nicholas J. Wareham
- MRC Epidemiology Unit, Institute of Metabolic Science, Cambridge, United Kingdom
| | - Brenda W. Penninx
- Department of Psychiatry/EMGO Institute, Neuroscience Campus, VU University Medical Center, Amsterdam, The Netherlands
- Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands
- Department of Psychiatry, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Ilja M. Nolte
- Unit of Genetic Epidemiology and Bioinformatics, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Martin McBride
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - William H. Miller
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Stuart A. Nicklin
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Andrew H. Baker
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Delyth Graham
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Robert A. McDonald
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Jill P. Pell
- Public Health and Health Policy Section, University of Glasgow, Glasgo, United Kingdom
| | - Naveed Sattar
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Paul Welsh
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | - Patricia Munroe
- Clinical Pharmacology and Barts and the London Genome Centre, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London, United Kingdom
| | - Mark J. Caulfield
- Clinical Pharmacology and Barts and the London Genome Centre, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London, United Kingdom
| | - Alberto Zanchetti
- Istituto Auxologico Italiano, Milan, Italy
- University of Milano, Milano, Italy
| | - Anna F. Dominiczak
- Institute of Cardiovascular and Medical Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
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Childhood course of renal insufficiency in a family with a uromodulin gene mutation. Pediatr Nephrol 2010; 25:1355-60. [PMID: 20151160 PMCID: PMC4264542 DOI: 10.1007/s00467-009-1436-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 12/17/2009] [Accepted: 12/18/2009] [Indexed: 10/19/2022]
Abstract
Mutations in the UMOD gene encoding uromodulin (Tamm-Horsfall glycoprotein) result in the autosomal dominant transmission of progressive renal insufficiency and hypo-uricosuric hyperuricemia leading to gout at an early age. The clinical appearance is characterized by renal insufficiency and gout occurring in the late teenage years, with end-stage kidney disease characteristically developing between 40 and 70 years of age. This report provides a long-term characterization of renal functional decline in three children from one family with a novel UMOD mutation (c.891T>G, p.C297W) who received allopurinol and a low protein diet. While renal functional decline is slow in individuals with UMOD mutations, it may appear early in life and be associated with marked hyperuricemia. Anemia was also noted in this family.
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Williams SE, Reed AAC, Galvanovskis J, Antignac C, Goodship T, Karet FE, Kotanko P, Lhotta K, Morinière V, Williams P, Wong W, Rorsman P, Thakker RV. Uromodulin mutations causing familial juvenile hyperuricaemic nephropathy lead to protein maturation defects and retention in the endoplasmic reticulum. Hum Mol Genet 2009; 18:2963-74. [PMID: 19465746 DOI: 10.1093/hmg/ddp235] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Familial juvenile hyperuricaemic nephropathy (FJHN), an autosomal dominant disorder, is caused by mutations in the UMOD gene, which encodes Uromodulin, a glycosylphosphatidylinositol-anchored protein that is expressed in the thick ascending limb of the loop of Henle and excreted in the urine. Uromodulin contains three epidermal growth factor (EGF)-like domains, a cysteine-rich region which includes a domain of eight cysteines and a zona pellucida (ZP) domain. Over 90% of UMOD mutations are missense, and 62% alter a cysteine residue, implicating a role for protein misfolding in the disease. We investigated 20 northern European FJHN probands for UMOD mutations. Wild-type and mutant Uromodulins were functionally studied by expression in HeLa cells and by the use of western blot analysis and confocal microscopy. Six different UMOD missense mutations (Cys32Trp, Arg185Gly, Asp196Asn, Cys217Trp, Cys223Arg and Gly488Arg) were identified. Patients with UMOD mutations were phenotypically similar to those without UMOD mutations. The mutant Uromodulins had significantly delayed maturation, retention in the endoplasmic reticulum (ER) and reduced expression at the plasma membrane. However, Gly488Arg, which is the only mutation we identified in the ZP domain, was found to be associated with milder in vitro abnormalities and to be the only mutant Uromodulin detected in conditioned medium from transfected cells, indicating that the severity of the mutant phenotypes may depend on their location within the protein. Thus, FJHN-causing Uromodulin mutants are retained in the ER, with impaired intracellular maturation and trafficking, thereby indicating mechanisms whereby Uromodulin mutants may cause the phenotype of FJHN.
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Affiliation(s)
- Siân E Williams
- Academic Endocrine Unit, Churchill Hospital, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Headington, Oxford OX3 7LJ, UK
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24
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Wu TH, Hsieh SC, Li KJ, Wu CH, Yu CL, Yang AH, Tsai CY. Altered glycosylation of Tamm-Horsfall glycoprotein derived from renal allograft recipients leads to changes in its biological function. Transpl Immunol 2008; 18:237-45. [PMID: 18047931 DOI: 10.1016/j.trim.2007.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 07/08/2007] [Accepted: 07/11/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND Human urinary Tamm-Horsfall glycoprotein (THP) is a pleotropic protein that binds different cytokines and stimulates various immunocompetent cells. It is unclear whether these important functions of THP are altered in renal transplant patients. METHODS We purified THPs from normal individuals (N-THP) and renal transplant patients receiving potent immunosuppressants (R-THP). The carbohydrate (CHO) compositions of THPs were probed by lectin-blotting and lectin-binding ELISA. The functions of THP were assessed by immune cell-stimulation as well as C1q, IL-1beta, IL-8 and TNF-alpha-binding assays. The roles of CHO moieties in THPs were analyzed using CHO-degrading enzyme digestion. RESULTS Compared to that of N-THP, the binding capacity of R-THP to Maackia amurensis, Galanthus nivalis and Datura stamonium decreased, indicating that R-THP contained lesser amount of Siaalpha(2,3)Gal/GalNAc, mannose residues, and beta(1,4)GlcNAc, but not GlcNAc/branched mannose. The binding capacity of R-THP to complement C1q and tumor necrosis factor (TNF)-alpha was also decreased. The stimulating effect of R-THP on mononuclear cell (MNC) proliferation and polymorphonuclear neutrophil (PMN) phagocytosis was less potent than that of N-THP. We found that the defective MNC-stimulation by R-THP was due to impaired NF-kappaB p52 nuclear translocation. The cell-stimulating effects of N- and R-THP could be abolished by digesting them with CHO-degrading enzymes, beta-galactosidase and neuraminidase. Interestingly, a potent apoptosis-inducing effect of R-THP on MNC and PMN was noted. CONCLUSIONS R-THP is not only modified in glycosylation but bears an apoptosis-inducing capacity on MNC and PMN, leading to an impaired immune function in renal transplant patients.
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Affiliation(s)
- Tsai-Hung Wu
- Division of Nephrology, Taipei Veterans General Hospital, and Institute of Clinical Medicine, National Yang-Ming University, Taiwan
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25
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Takiue Y, Hosoyamada M, Yokoo T, Kimura M, Shibasaki T. Progressive Accumulation of Intrinsic Mouse Uromodulin in the Kidneys of Transgenic Mice Harboring the Mutant Human Uromodulin Gene. Biol Pharm Bull 2008; 31:405-11. [DOI: 10.1248/bpb.31.405] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yuichi Takiue
- Department of Pharmacotherapeutics, Kyoritsu University of Pharmacy
| | | | - Takuya Yokoo
- Department of Pharmacotherapeutics, Kyoritsu University of Pharmacy
| | - Masaki Kimura
- Department of Pharmacotherapeutics, Kyoritsu University of Pharmacy
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Fenton RA, Knepper MA. Mouse models and the urinary concentrating mechanism in the new millennium. Physiol Rev 2007; 87:1083-112. [PMID: 17928581 DOI: 10.1152/physrev.00053.2006] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Our understanding of urinary concentrating and diluting mechanisms at the end of the 20th century was based largely on data from renal micropuncture studies, isolated perfused tubule studies, tissue analysis studies and anatomical studies, combined with mathematical modeling. Despite extensive data, several key questions remained to be answered. With the advent of the 21st century, a new approach, transgenic and knockout mouse technology, is providing critical new information about urinary concentrating processes. The central goal of this review is to summarize findings in transgenic and knockout mice pertinent to our understanding of the urinary concentrating mechanism, focusing chiefly on mice in which expression of specific renal transporters or receptors has been deleted. These include the major renal water channels (aquaporins), urea transporters, ion transporters and channels (NHE3, NKCC2, NCC, ENaC, ROMK, ClC-K1), G protein-coupled receptors (type 2 vasopressin receptor, prostaglandin receptors, endothelin receptors, angiotensin II receptors), and signaling molecules. These studies shed new light on several key questions concerning the urinary concentrating mechanism including: 1) elucidation of the role of water absorption from the descending limb of Henle in countercurrent multiplication, 2) an evaluation of the feasibility of the passive model of Kokko-Rector and Stephenson, 3) explication of the role of inner medullary collecting duct urea transport in water conservation, 4) an evaluation of the role of tubuloglomerular feedback in maintenance of appropriate distal delivery rates for effective regulation of urinary water excretion, and 5) elucidation of the importance of water reabsorption in the connecting tubule versus the collecting duct for maintenance of water balance.
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Affiliation(s)
- Robert A Fenton
- Water and Salt Research Center, Institute of Anatomy, University of Aarhus, Aarhus, Denmark.
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27
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Pfistershammer K, Klauser C, Leitner J, Stöckl J, Majdic O, Weichhart T, Sobanov Y, Bochkov V, Säemann M, Zlabinger G, Steinberger P. Identification of the scavenger receptors SREC-I, Cla-1 (SR-BI), and SR-AI as cellular receptors for Tamm-Horsfall protein. J Leukoc Biol 2007; 83:131-8. [PMID: 17928461 DOI: 10.1189/jlb.0407231] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Tamm-Horsfall protein (THP) is expressed exclusively in the kidney and constitutes the most abundant protein in urine. An important role for THP in antibacterial host defense but also in inflammatory disorders of the urogenital tract has been suggested. In line with this, THP has been shown recently to potently activate macrophages and dendritic cells (DC) via the toll-like receptor 4 (TLR4) pathway. We show here that THP interacts specifically with surface structures on DC and provides evidence that they are distinct from TLR4. Using retroviral expression cloning, we have identified one such receptor as the scavenger receptor (SR) expressed by endothelial cells I (SREC-I). In addition, we found that two other receptors for acetylated low-density lipoprotein (AcLDL), namely scavenger receptors AI (SR-AI) and Cla-1 (SR-BI), also serve as receptors for THP. SREC-I/THP interaction is of high affinity (16.8+/-6.8 nM), whereas Cla-1 and SR-AI have lower affinities for THP (396 nM+/-114 nM and 802 nM+/-157 nM, respectively). The interaction of THP with these molecules is fully blocked by AcLDL. However, AcLDL only partially blocks binding of THP to DC, and a series of experiments did not support a role in DC activation for SR interacting with THP and AcLDL. Thus, our data point to the existence of additional receptors for THP, which mediate TLR4-dependent DC activation. Interaction and up-take of THP by SR might play an important role in local host defense and could contribute to inflammatory kidney diseases associated with THP-specific antibody responses.
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Affiliation(s)
- Katharina Pfistershammer
- Institute of Immunology, Center of Physiology and Pathophysiology, Medical University of Vienna, Borschkegasse 8a, A-1090, Vienna, Austria
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28
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Wolf MTF, Beck BB, Zaucke F, Kunze A, Misselwitz J, Ruley J, Ronda T, Fischer A, Eifinger F, Licht C, Otto E, Hoppe B, Hildebrandt F. The Uromodulin C744G mutation causes MCKD2 and FJHN in children and adults and may be due to a possible founder effect. Kidney Int 2007; 71:574-81. [PMID: 17245395 DOI: 10.1038/sj.ki.5002089] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Autosomal dominant medullary cystic kidney disease type 2 (MCKD2) is a tubulo-in terstitial nephropathy that causes renal salt wasting, hyperuricemia, gout, and end-stage renal failure in the fifth decade of life. This disorder was described to have an age of onset between the age of 20-30 years or even later. Mutations in the Uromodulin (UMOD) gene were published in patients with familial juvenile hyperuricemic nephropathy (FJHN) and MCKD2. Clinical data and blood samples of 16 affected individuals from 11 different kindreds were collected. Mutational analysis of the UMOD gene was performed by exon polymerase chain reaction (PCR) and direct sequencing. We found the heterozygous C744G (Cys248Trp) mutation, which was originally published by our group, in an additional four kindreds from Europe and Turkey. Age of onset ranged from 3 years to 39 years. The phenotype showed a variety of symptoms such as urinary concentration defect, vesicoureteral reflux, urinary tract infections, hyperuricemia, hypertension, proteinuria, and renal hypoplasia. Haplotype analysis showed cosegragation with the phenotype in all eight affected individuals indicating that the C744G mutation may be due to a founder effect. Moreover, we describe a novel T229G (Cys77Gly) mutation in two affecteds of one kindred. Three of the affected individuals were younger than 10 years at the onset of MCKD2/FJHN. Symptoms include recurrent urinary tract infections compatible with the published phenotype of the Umod knockout mouse model. This emphasizes that MCKD2 is not just a disease of the young adult but is also relevant for children.
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Affiliation(s)
- M T F Wolf
- Department of Pediatric Nephrology of the University Children's Hospital, University of Cologne, Cologne, Germany
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Bernascone I, Vavassori S, Di Pentima A, Santambrogio S, Lamorte G, Amoroso A, Scolari F, Ghiggeri GM, Casari G, Polishchuk R, Rampoldi L. Defective intracellular trafficking of uromodulin mutant isoforms. Traffic 2006; 7:1567-79. [PMID: 17010121 DOI: 10.1111/j.1600-0854.2006.00481.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Medullary cystic kidney disease/familial juvenile hyperuricemic nephropathy (MCKD/FJHN) are autosomal dominant renal disorders characterized by tubulo-interstitial fibrosis, hyperuricemia and medullary cysts. They are caused by mutations in the gene encoding uromodulin, the most abundant protein in urine. Uromodulin (or Tamm-Horsfall protein) is a glycoprotein that is exclusively expressed by epithelial tubular cells of the thick ascending limb of Henle's loop and distal convoluted tubule. To date, 37 different uromodulin mutations have been described in patients with MCKD/FJHN. Interestingly, 60% of them involve one of the 48 conserved cysteine residues. We have previously shown that cysteine-affecting mutations could lead to partial endoplasmic reticulum (ER) retention. In this study, as a further step in understanding uromodulin biology in health and disease, we provide the first extensive study of intracellular trafficking and subcellular localization of wild-type and mutant uromodulin isoforms. We analyzed a set of 12 different uromodulin mutations that were representative of the different kind of mutations identified so far by different experimental approaches (immunofluorescence, electron microscopy, biochemistry and in vivo imaging) in transiently transfected HEK293 and Madin-Darby canine kidney cells. We assessed protein processing in the secretory pathway and could demonstrate that although to different extent, all uromodulin mutations lead to defective ER to Golgi protein transport, suggesting a common pathogenetic mechanism in MCKD/FJHN.
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Affiliation(s)
- Ilenia Bernascone
- Dulbecco Telethon Institute, DIBIT, San Raffaele Scientific Institute, Via Olgettina 58, 20132 Milan, Italy
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Abstract
The prevalence of gout appears to be rapidly increasing worldwide and is no longer a disorder suffered primarily by over-fed alcohol consumers. Emerging risk factors include longevity, metabolic syndrome, and new classes of pharmacologic agents. In some ethnic populations, no obvious risk factors can explain the high incidence of hyperuricemia and gout, suggesting a genetic liability. Studies to identify genes associated with gout have included families with defects in purine metabolism, as well as families in whom the occurrence of gout is secondary to renal disorders such as juvenile hyperuricemic nephropathy and medullary cystic kidney disease. Case-control studies of isolated aboriginal cohorts suffering from primary gout have revealed several chromosomal loci that may harbor genes that are important to the development and/or progression of gout.
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31
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Serafini-Cessi F, Monti A, Cavallone D. N-Glycans carried by Tamm-Horsfall glycoprotein have a crucial role in the defense against urinary tract diseases. Glycoconj J 2005; 22:383-94. [PMID: 16622944 DOI: 10.1007/s10719-005-2142-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tamm-Horsfall glycoprotein (THGP), produced exclusively by renal cells from the thick ascending limb of Henle's loop, is attached by a glycosyl-phosphatidylinositol (GPI)-anchor to the luminal face of the cells. Urinary excretion of THGP (50-100 mg/day) occurs upon proteolytic cleavage of the large ectodomain of the GPI-anchored form. N-Glycans, consisting of a large repertoire of sialylated polyantennary chains and high-mannose structures, account for approximately 30% of the weight of human urinary THGP. We describe: (i) the involvement of urinary THGP high-mannose glycans in defense against infections of the urinary tract, caused by type-1 fimbriated Escherichia coli, which recognize high-mannose structures, (ii) the role of GalNAcbeta1-4(NeuAcalpha2-3)Galbeta1-4GlcNAcbeta1-3Gal (Sd(a) determinant) carried by human THGP in protecting the distal nephron from colonization of type-S fimbriated E. coli which recognise NeuAcalpha2-3Gal, (iii) the inhibitory effect of sialylated THGP on crystal aggregation of calcium oxalate and calcium phosphate, thus preventing nephrolithiasis. Finally, we outline the importance of N-glycans in promoting the polymerization of THGP, a process resulting in the formation of homopolymers with an M(r) of several million in urine. Since THGP defense against diseases of the urinary tract mainly consists in binding damaging agents, its ability to behave as a multivalent ligand significantly enhances this protective role.
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Affiliation(s)
- Franca Serafini-Cessi
- Department of Experimental Pathology, University of Bologna, Italy. serafini@.alma.unibo.it
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32
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Abstract
Many eukaryotic proteins share a sequence designated as the zona pellucida (ZP) domain. This structural element, present in extracellular proteins from a wide variety of organisms, from nematodes to mammals, consists of approximately 260 amino acids with eight conserved cysteine (Cys) residues and is located close to the C terminus of the polypeptide. ZP domain proteins are often glycosylated, modular structures consisting of multiple types of domains. Predictions can be made about some of the structural features of the ZP domain and ZP domain proteins. The functions of ZP domain proteins vary tremendously, from serving as structural components of egg coats, appendicularian mucous houses, and nematode dauer larvae, to serving as mechanotransducers in flies and receptors in mammals and nonmammals. Generally, ZP domain proteins are present in filaments and/or matrices, which is consistent with the role of the domain in protein polymerization. A general mechanism for assembly of ZP domain proteins has been presented. It is likely that the ZP domain plays a common role despite its presence in proteins of widely diverse functions.
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Affiliation(s)
- Luca Jovine
- Brookdale Department of Molecular, Cell, and Developmental Biology, Mount Sinai School of Medicine, New York, New York 10029-6574, USA.
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33
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Choi SW, Ryu OH, Choi SJ, Song IS, Bleyer AJ, Hart TC. Mutant Tamm-Horsfall Glycoprotein Accumulation in Endoplasmic Reticulum Induces Apoptosis Reversed by Colchicine and Sodium 4-Phenylbutyrate. J Am Soc Nephrol 2005; 16:3006-14. [PMID: 16135773 DOI: 10.1681/asn.2005050461] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
As a consequence of uromodulin gene mutations, individuals develop precocious hyperuricemia, gout, and progressive renal failure. In vitro studies suggest that pathologic accumulation of uromodulin/Tamm-Horsfall glycoprotein (THP) occurs in the endoplasmic reticulum (ER), but the pathophysiology of renal damage is unclear. It was hypothesized that programmed cell death triggered by accumulation of misfolded THP in the ER causes progressive renal disease. Stably transfected human embryonic kidney 293 cells and immortalized thick ascending limb of Henle's loop cells with wild-type and mutated uromodulin cDNA were evaluated to test this hypothesis. Immunocytochemistry, ELISA, and deglycosylation studies indicated that accumulation of mutant THP occurred in the ER. FACS analyses showed a significant increase in early apoptosis signal in human embryonic kidney 293 and thick ascending limb of Henle's loop cells that were transfected with mutant uromodulin constructs. Colchicine and sodium 4-phenylbutyrate treatment increased secretion of THP from the ER to the cell membrane and into the culture media and significantly improved cell viability. These findings indicate that intracellular accumulation of THP facilitates apoptosis and that this may provide the pathologic mechanism responsible for the progressive renal damage associated with uromodulin gene mutations. Colchicine and sodium 4-phenylbutyrate reverse these processes and could potentially be beneficial in ameliorating the progressive renal damage in uromodulin-associated kidney diseases.
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Affiliation(s)
- Sung Won Choi
- NIH-NIDCR, 10 Center Drive, Building 10, Room 5-2531, Bethesda, MD 20892-1432, USA
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Bachmann S, Mutig K, Bates J, Welker P, Geist B, Gross V, Luft FC, Alenina N, Bader M, Thiele BJ, Prasadan K, Raffi HS, Kumar S. Renal effects of Tamm-Horsfall protein (uromodulin) deficiency in mice. Am J Physiol Renal Physiol 2005; 288:F559-67. [PMID: 15522986 DOI: 10.1152/ajprenal.00143.2004] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The Tamm-Horsfall protein (THP; uromodulin), the dominant protein in normal urine, is produced exclusively in the thick ascending limb of Henle's loop. THP mutations are associated with disease; however, the physiological role of THP remains obscure. We generated THP gene-deficient mice (THP −/−) and compared them with wild-type (WT) mice. THP −/− mice displayed anatomically normal kidneys. Steady-state electrolyte handling was not different between strains. Creatinine clearance was 63% lower in THP −/− than in WT mice ( P < 0.05). Sucrose loading induced no changes between strains. However, water deprivation for 24 h decreased urine volume from 58 ± 9 to 28 ± 4 μl·g body wt−1·24 h−1 in WT mice ( P < 0.05), whereas in THP −/− mice this decrease was less pronounced (57 ± 4 to 41 ± 5 μl·g body wt−1·24 h−1; P < 0.05), revealing significant interstrain difference ( P < 0.05). We further used RT-PCR, Northern and Western blotting, and histochemistry to study renal transporters, channels, and regulatory systems under steady-state conditions. We found that major distal transporters were upregulated in THP −/− mice, whereas juxtaglomerular immunoreactive cyclooxygenase-2 (COX-2) and renin mRNA expression were both decreased in THP −/− compared with WT mice. These observations suggest that THP influences transporters in Henle's loop. The decreased COX-2 and renin levels may be related to an altered tubular salt load at the macula densa, whereas the increased expression of distal transporters may reflect compensatory mechanisms. Our data raise the hypothesis that THP plays an important regulatory role in the kidney.
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Affiliation(s)
- Sebastian Bachmann
- Medical Faculty of the Charité, Department of Anatomy, Franz Volhard Clinic, HELIOS Clinics and Max Delbrück Center for Molecular Medicine, Berlin, Germany.
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Wolf MTF, Zalewski I, Martin FC, Ruf R, Müller D, Hennies HC, Schwarz S, Panther F, Attanasio M, Acosta HG, Imm A, Lucke B, Utsch B, Otto E, Nurnberg P, Nieto VG, Hildebrandt F. Mapping a new suggestive gene locus for autosomal dominant nephrolithiasis to chromosome 9q33.2-q34.2 by total genome search for linkage. Nephrol Dial Transplant 2005; 20:909-14. [PMID: 15741201 DOI: 10.1093/ndt/gfh754] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Nephrolithiasis is a complex, multifactorial disease resulting from genetic and environmental interaction. The pathogenesis of nephrolithiasis is far from being understood. So far, no gene locus for autosomal dominant nephrolithiasis only has been described. We here identified a new suggestive gene locus for autosomal dominant nephrolithiasis by a genome-wide search for linkage in a Spanish kindred with nephrolithiasis. METHODS Clinical data, blood and urine samples of 18 individuals from a Spanish kindred with nephrolithiasis were collected. We performed a genome-wide search for linkage using 380 polymorphic microsatellite markers. RESULTS Nephrolithiasis segregated in this Spanish kindred in a pattern compatible with autosomal dominant inheritance. The total genome search yielded the highest two-point LOD score of Z(max) = 1.99 (theta = 0) for marker D9S159 on chromosome 9q33.2-q34.2. Multipoint analysis of 24 polymorphic markers used for further fine mapping resulted in a LOD score of Z(max) = 2.7 (theta = 0) for markers D9S1881-D9S164, thereby identifying a new gene locus for autosomal dominant nephrolithiasis (NPL1). Two recombination events define D9S1850 as the centromeric flanking marker and D9S1818 as the telomeric flanking marker, restricting the NPL1 locus to a 14 Mb interval. CONCLUSION We here identified a new suggestive gene locus (NPL1) for autosomal dominant nephrolithiasis. It is localized on chromosome 9q33.2-q34.2. The identification of the responsible gene will provide new insights into the molecular basis of nephrolithiasis.
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Affiliation(s)
- Matthias T F Wolf
- Department of Pediatrics and Communicable Diseases, University of Michigan, 8220C MSRB III, 1150 West Medical Center Drive, Ann Arbor, MI 48109-0646, USA
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Bleyer AJ, Hart TC, Shihabi Z, Robins V, Hoyer JR. Mutations in the uromodulin gene decrease urinary excretion of Tamm-Horsfall protein. Kidney Int 2004; 66:974-7. [PMID: 15327389 DOI: 10.1111/j.1523-1755.2004.00845.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mutations in the uromodulin (UMOD) gene that encodes Tamm-Horsfall protein (THP) cause an autosomal-dominant form of chronic renal failure. We have now investigated effects of UMOD gene mutations on protein expression by quantitatively measuring THP excretion. METHODS THP excretion was determined by enzyme-linked immunosorbent assay (ELISA) of urine collections obtained from 16 related individuals with a 27 bp deletion in the UMOD gene and seven individuals with other UMOD mutations. THP excretion of 22 control subjects (18 genetically related individuals and four spouses in the UMOD deletion family) was also determined. RESULTS The 16 individuals carrying the deletion mutation excreted 5.8 +/- 6.3 mg THP/g creatinine into their urine. The 18 unaffected relatives from the same family excreted 40.8 +/- 9.7 mg THP/g creatinine (P < 0.0001) and the four spouses excreted 43.9 +/- 25.1 mg THP/g creatinine (P < 0.0001 vs. individuals with the deletion mutation). THP excretion of seven individuals with other UMOD gene mutations was also extremely low (range of 0.14 to 5.9 mg THP/g creatinine). All individuals with UMOD mutations had low THP excretion, irrespective of gender, glomerular filtration rate (GFR), or age. CONCLUSION These studies quantitatively show that the autosomal-dominant gene mutations responsible for UMOD-associated kidney disease cause a profound reduction of THP excretion. We speculate that this suppression of normal THP excretion reflects deleterious effects of mutated THP within the kidney. Such effects may also play an important role in the pathogenesis of the progressive renal failure observed in patients with UMOD gene mutations.
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Affiliation(s)
- Anthony J Bleyer
- Section on Nephrology, Wake Forest University School of Medicine Medical Center, Winston-Salem, North Carolina 27157, USA.
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Pham PC, Devuyst O, Pham PT, Matsumoto N, Shih RNG, Jo OD, Yanagawa N, Sun AM. Hypertonicity increases CLC-5 expression in mouse medullary thick ascending limb cells. Am J Physiol Renal Physiol 2004; 287:F747-52. [PMID: 15161605 DOI: 10.1152/ajprenal.00229.2003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Genetic studies indicated that mutations of the chloride channel CLC-5 in the kidney are responsible for a group of clinical disorders, collectively called Dent's disease. In the kidney, CLC-5 was found to be expressed in the proximal tubule, medullary thick ascending limb (mTAL) of loop of Henle, and intercalated cells of the collecting tubule. In proximal tubular cells, CLC-5 was found to play an important role in receptor-mediated endocytosis. However, the functional roles of CLC-5 in mTAL and collecting tubules remain unclear. Because mTAL is normally exposed to a hypertonic environment, we aimed to examine the effect of hypertonicity on CLC-5 expression in this nephron segment. Our studies revealed that exposure to hypertonicity (up to 550 mosM) increased CLC-5 mRNA and protein levels in a murine mTAL cell line (MTAL) but not in an opossum kidney (OK) proximal tubular cell line. A similar effect was also found in mouse kidneys, where CLC-5 expression was enhanced in renal medulla, but not cortex, after 48 h of water deprivation. We also tested the effect of hypertonicity on endocytotic activity and found that exposure to hypertonicity caused a significant decrease in cellular uptake of FITC-labeled albumin in OK but not in MTAL cells. Our results suggest that CLC-5 expression is upregulated by hypertonicity in mTAL cells but not in proximal tubular cells. We speculate that the increased CLC-5 levels in mTAL may serve to maintain the endocytotic activity in a hypertonic environment.
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Affiliation(s)
- Phuong-Chi Pham
- Renal Division, Department of Medicine, Olive View-UCLA Medical Center, Sylmar, CA 91342, USA.
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Kudo E, Kamatani N, Tezuka O, Taniguchi A, Yamanaka H, Yabe S, Osabe D, Shinohara S, Nomura K, Segawa M, Miyamoto T, Moritani M, Kunika K, Itakura M. Familial juvenile hyperuricemic nephropathy: Detection of mutations in the uromodulin gene in five Japanese families. Kidney Int 2004; 65:1589-97. [PMID: 15086896 DOI: 10.1111/j.1523-1755.2004.00559.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Familial juvenile hyperuricemic nephropathy (FJHN) is an autosomal-dominant disease characterized by hyperuricemia of underexcretion type, gout, and chronic renal failure. We previously reported linkage on chromosome 16p12 in a large Japanese family designated as family 1 in the present study. Recent reports on the discovery of mutations of the uromodulin (UMOD) gene in families with FJHN encouraged us to screen UMOD mutations in Japanese families with FJHN, including family 1. METHODS Six unrelated Japanese families with FJHN were examined for mutations of the UMOD gene by direct sequencing. To confirm the results of the mutation screening, parametric linkage analyses were performed using markers in 16p12 region and around other candidate genes of FJHN. RESULTS Five separate heterozygous mutations (Cys52Trp, Cys135Ser, Cys195Phe, Trp202Ser, and Pro236Leu) were found in five families, including family 1. All mutations were co-segregated with the disease phenotype in all families, except for family 1, in which an individual in the youngest generation was found as a phenocopy by the genetic testing. Revised multipoint linkage analysis showed that the UMOD gene was located in the interval showing logarithm of odds (LOD) score above 6.0. One family carrying no mutation in the UMOD gene showed no linkage to the medullary cystic kidney disease type 1 (MCKD1) locus, the genes of hepatocyte nuclear factor-1beta (HNF-1beta), or urate transporters URAT1 and hUAT. CONCLUSION Our results gave an evidence for the mutation of the UMOD gene in the majority of Japanese families with FJHN. Genetic heterogeneity of FJHN was also confirmed. Genetic testing is necessary for definite diagnosis in some cases especially in the young generation.
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Affiliation(s)
- Eiji Kudo
- Division of Genetic Information, Institute for Genome Research, The University of Tokushima, Tokushima, Japan.
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Wolf MTF, Mucha BE, Attanasio M, Zalewski I, Karle SM, Neumann HPH, Rahman N, Bader B, Baldamus CA, Otto E, Witzgall R, Fuchshuber A, Hildebrandt F. Mutations of the Uromodulin gene in MCKD type 2 patients cluster in exon 4, which encodes three EGF-like domains. Kidney Int 2003; 64:1580-7. [PMID: 14531790 DOI: 10.1046/j.1523-1755.2003.00269.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Autosomal-dominant medullary cystic kidney disease type 2 (MCKD2) is a tubulointerstitial nephropathy that causes renal salt wasting, hyperuricemia, gout, and end-stage renal failure in the fifth decade of life. The chromosomal locus for MCKD2 was localized on chromosome 16p12. Within this chromosomal region, Uromodulin (UMOD) was located as a candidate gene. UMOD encodes the Tamm-Horsfall protein. By sequence analysis, one group formerly excluded UMOD as the disease-causing gene. In contrast, recently, another group described mutations in the UMOD gene as responsible for MCKD2 and familial juvenile hyperuricemic nephropathy (FJHN). METHODS Haplotype analysis for linkage to MCKD2 was performed in 25 MCKD families. In the kindreds showing linkage to the MCKD2 locus on chromosome 16p12, mutational analysis of the UMOD gene was performed by exon polymerase chain reaction (PCR) and direct sequencing. RESULTS In 19 families, haplotype analysis was compatible with linkage to the MCKD2 locus. All these kindreds were examined for mutations in the UMOD gene. In three different families, three novel heterozygous mutations in the UMOD gene were found and segregated with the phenotype in affected individuals. Mutations were found only in exon 4. CONCLUSION We confirm the UMOD gene as the disease-causing gene for MCKD2. All three novel mutations were found in the fourth exon of UMOD, in which all mutations except one (this is located in the neighboring exon 5) published so far are located. These data point to a specific role of exon 4 encoded sequence of UMOD in the generation of the MCKD2 renal phenotype.
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Affiliation(s)
- Matthias T F Wolf
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan 48109, USA
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Serafini-Cessi F, Malagolini N, Cavallone D. Tamm-Horsfall glycoprotein: biology and clinical relevance. Am J Kidney Dis 2003; 42:658-76. [PMID: 14520616 DOI: 10.1016/s0272-6386(03)00829-1] [Citation(s) in RCA: 277] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tamm-Horsfall glycoprotein (THP) is the most abundant urinary protein in mammals. Urinary excretion occurs by proteolytic cleavage of the large ectodomain of the glycosyl phosphatidylinositol-anchored counterpart exposed at the luminal cell surface of the thick ascending limb of Henle's loop. We describe the physical-chemical structure of human THP and its biosynthesis and interaction with other proteins and leukocytes. The clinical relevance of THP reported here includes: (1) involvement in the pathogenesis of cast nephropathy, urolithiasis, and tubulointerstitial nephritis; (2) abnormalities in urinary excretion in renal diseases; and (3) the recent finding that familial juvenile hyperuricemic nephropathy and autosomal dominant medullary cystic kidney disease 2 arise from mutations of the THP gene. We critically examine the literature on the physiological role and mechanism(s) that promote urinary excretion of THP. Some lines of research deal with the in vitro immunoregulatory activity of THP, termed uromodulin when isolated from urine of pregnant women. However, an immunoregulatory function in vivo has not yet been established. In the most recent literature, there is renewed interest in the capacity of urinary THP to compete efficiently with urothelial cell receptors, such as uroplakins, in adhering to type 1 fimbriated Escherichia coli. This property supports the notion that abundant THP excretion in urine is promoted in the host by selective pressure to obtain an efficient defense against urinary tract infections caused by uropathogenic bacteria.
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41
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Cavallone D, Malagolini N, Frascà GM, Stefoni S, Serafini-Cessi F. Salt-precipitation method does not isolate to homogeneity Tamm-Horsfall glycoprotein from urine of proteinuric patients and pregnant women. Clin Biochem 2002; 35:405-10. [PMID: 12270772 DOI: 10.1016/s0009-9120(02)00329-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVE Assessment of the degree of purification of Tamm-Horsfall glycoprotein from anomalous urine. DESIGN AND METHODS Two methods have been compared: the method of Tamm & Horsfall (T&H method) consisting in the precipitation of THP by the addition to urine of NaCl up to 0.58 mol/L and the filtration of urine through a diatomaceous earth filter (DEF method) in which THP is selectively trapped because of its gelation/aggregation tendency. The purity of THP preparations has been evaluated by SDS-PAGE analysis and Western blotting developed with anti immunoglobulin G (IgG) antibodies and antichorionic gonadotropin antibodies. RESULTS All THPs isolated by T&H method from proteinuric patients were contaminated by IgG and one of the five preparations from pregnant women even by chorionic gonadotropin. A smaller or no contamination was found in THPs isolated by DEF method. CONCLUSIONS Although albumin is the most abundant protein in the anomalous urine, it never appears in THP preparations. The consistent contamination with IgG of THP prepared by salt precipitation-method might be related to the formation of a stable complex between the two proteins.
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Affiliation(s)
- Daniela Cavallone
- Department of Experimental Pathology, University of Bologna, Via S Giacomo 14, 40126 Bologna, Italy
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42
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Kreft B, Jabs WJ, Laskay T, Klinger M, Solbach W, Kumar S, van Zandbergen G. Polarized expression of Tamm-Horsfall protein by renal tubular epithelial cells activates human granulocytes. Infect Immun 2002; 70:2650-6. [PMID: 11953407 PMCID: PMC127949 DOI: 10.1128/iai.70.5.2650-2656.2002] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In renal bacterial infections granulocytes are of major importance in the primary immune defense against invading pathogens. However, the mechanisms of granulocytic activation in renal interstitial invasion have not been clarified. Renal tubular epithelial cell mechanisms inducing granulocytic activation and bacterial killing may include tubular cell expression of Tamm-Horsfall protein (THP), a urinary protein that is known to enhance cytokine expression in monocytes. We studied the role of THP in granulocytic activation. A strong binding of THP to human granulocytes was demonstrated by fluorescence-activated cell sorter analysis. Urinary THP and supernatants of THP-expressing cultured tubular epithelial cells (MDCK) enhanced interleukin-8 (IL-8) expression by human granulocytes. Renal tubular cells growing polarized on polycarbonate membranes were used to study apical versus basal THP expression. By electron microscopy THP immunoreactivity was exclusively found on the apical surfaces of tubular cells and was absent on the basolateral cell membrane. In the apical cell culture compartment we found significantly more stimulatory activity for granulocytic IL-8 expression. CD62L, a selectin less expressed in activated granulocytes, was decreased in granulocytes incubated with urinary THP and in supernatants of THP-producing renal tubular cells but not in supernatants from THP-negative cells. Again, the effect on CD62L expression was found only in apical culture media and was absent in the basal compartment. In summary our data give evidence that renal tubular cell THP expression may be relevant in kidney diseases since THP is a potent activator of human granulocytes. The regulation of apical versus basal THP expression and release in vivo may be crucial in the induction of the inflammatory response, e.g., in bacterial renal diseases.
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Affiliation(s)
- B Kreft
- Department of Internal Medicine, Division of Infectious Diseases, Medical University of Lübeck, Lübeck, Germany.
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Cavallone D, Malagolini N, Serafini-Cessi F. Mechanism of release of urinary Tamm-Horsfall glycoprotein from the kidney GPI-anchored counterpart. Biochem Biophys Res Commun 2001; 280:110-4. [PMID: 11162486 DOI: 10.1006/bbrc.2000.4090] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human Tamm-Horsfall glycoprotein (THP) is synthesised in the thick ascending limb of Henle and convoluted distal tubules, inserted into luminal cell-surface by the glycosyl-phosphatidylinositol (GPI)-anchor and excreted in urine at a rate of 50-100 mg per day. Up to date there is no indication on the way in which THP is excreted into the urinary fluid. In this study, we examined by Western blotting THP from human kidney in comparison to urinary THP. As expected for a GPI-anchored protein, THP was recovered from the kidney lysate in a Triton X-100 insoluble form, which moved in a sucrose gradient to a zone of low density. The apparent molecular weight of kidney THP appeared greater than that of urinary THP, but no difference in the electrophoretic mobility was observed when the former was subjected to GPI-specific phospholipase-C treatment, strongly suggesting that a proteolytic cleavage at the juxtamembrane-ectodomain of kidney THP is responsible for the urinary excretion.
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Affiliation(s)
- D Cavallone
- Department of Experimental Pathology, University of Bologna, Via S. Giacomo 14, 40126 Bologna, Italy
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Abstract
Remodeling of the plant cell surface occurs during the establishment of cell polarity, cellular differentiation, and organ development. This report demonstrates the existence of multiple glycosylphosphatidylinositol (GPI)-anchored proteins in the model plant Arabidopsis. Using two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), we also show that GPI-anchored proteins are a relatively abundant class of protein and that they are present at the plant plasma membrane. Furthermore, some of these proteins are released into the extracellular matrix. At least one of these is an arabinogalactan protein (AGP), a class of proteins known to be associated with cellular differentiation. Analysis of the amino acid sequences of two novel AGP-like proteins from Arabidopsis predicts that these proteins contain consensus signals for GPI-anchor addition. These findings support a model where GPI-anchored proteins are involved in the generation of specialized cell surfaces and extracellular signaling molecules.
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Affiliation(s)
- D J Sherrier
- University of Cambridge, Department of Biochemistry, United Kingdom
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Schaub TP, Kartenbeck J, König J, Spring H, Dörsam J, Staehler G, Störkel S, Thon WF, Keppler D. Expression of the MRP2 gene-encoded conjugate export pump in human kidney proximal tubules and in renal cell carcinoma. J Am Soc Nephrol 1999; 10:1159-69. [PMID: 10361853 DOI: 10.1681/asn.v1061159] [Citation(s) in RCA: 201] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Human kidney proximal tubule epithelia express the ATP-dependent export pump for anionic conjugates encoded by the MRP2 (cMRP/cMOAT) gene (symbol ABCC2). MRP2, the apical isoform of the multidrug resistance protein, is an integral membrane glycoprotein with a molecular mass of approximately 190 kD that was originally cloned from liver and localized to the canalicular (apical) membrane domain of hepatocytes. In this study, MRP2 was detected in human kidney cortex by reverse transcription-PCR followed by sequencing of a 826-bp cDNA fragment and by immunoblotting using two different antibodies. Human MRP2 was localized to the apical brush-border membrane domain of proximal tubules by double and triple immunofluorescence microscopy including laser scanning microscopy. The expression of MRP2 in renal cell carcinoma was studied by reverse transcription-PCR and immunoblotting in samples from patients undergoing tumor-nephrectomy without prior chemotherapy. Clear-cell carcinomas, originating from the proximal tubule epithelium, expressed MRP2 in 95% (18 of 19) of cases. Immunofluorescence microscopy of MRP2 in clear-cell carcinoma showed a lack of a distinct apical-to-basolateral tumor cell polarity and an additional localization of MRP2 on intracellular membranes. MRP2, the first cloned ATP-dependent export pump for anionic conjugates detected in human kidney, may be involved in renal excretion of various anionic endogenous substances, xenobiotics, and cytotoxic drugs. This conjugate-transporting ATPase encoded by the MRP2 gene has a similar substrate specificity as the multidrug resistance protein MRP1, and may contribute to the multidrug resistance of renal clear-cell carcinomas.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B/genetics
- ATP Binding Cassette Transporter, Subfamily B/isolation & purification
- Aged
- Aged, 80 and over
- Base Sequence
- Carcinoma, Renal Cell/chemistry
- Carcinoma, Renal Cell/genetics
- Clone Cells
- Dipeptidyl Peptidase 4/analysis
- Gene Expression
- Genes, MDR/genetics
- Genetic Markers
- Humans
- Immunoblotting
- Kidney Neoplasms/chemistry
- Kidney Neoplasms/genetics
- Kidney Tubules, Proximal/chemistry
- Membrane Transport Proteins
- Microscopy, Fluorescence
- Middle Aged
- Molecular Sequence Data
- Multidrug Resistance-Associated Protein 2
- Multidrug Resistance-Associated Proteins
- Polymerase Chain Reaction
- RNA, Messenger/analysis
- RNA, Neoplasm/analysis
- Reference Values
- Sensitivity and Specificity
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Affiliation(s)
- T P Schaub
- Division of Tumor Biochemistry, Deutsches Krebsforschungszentrum, Heidelberg, Germany
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46
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Cavallone D, Malagolini N, Serafini-Cessi F. Binding of human neutrophils to cell-surface anchored Tamm-Horsfall glycoprotein in tubulointerstitial nephritis. Kidney Int 1999; 55:1787-99. [PMID: 10231441 DOI: 10.1046/j.1523-1755.1999.00439.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Human Tamm-Horsfall glycoprotein (T-H) is a glycosylphosphatidylinositol-anchored protein exposed at the surface of distal nephron cells, and urinary T-H is the released soluble counterpart. The latter has been implicated in tubulointerstitial nephritis, and the proinflammatory potential has been related to its ability to bind in vitro human neutrophils (PMNs). We have examined the conditions required for the binding of neutrophils to cell-surface anchored T-H and the consequent effects. METHODS A HeLa cell-line derivative permanently transformed with human T-H cDNA and expressing T-H at the cell surface was used throughout the study. The adhesion of PMNs to cells expressing T-H was analyzed by immunofluorescence microscopy before and after the opsonization of cells with anti-T-H antibodies. The oxidative burst induced by adhesion of PMNs to the cells was determined by the activation of myeloperoxidase. Quantitative and qualitative changes in the release of T-H under the adhesion of activated PMNs were determined by dot-blot and Western blot analysis. RESULTS No binding of neutrophils to cell-surface-anchored T-H was observed. On the contrary, the opsonization of cells with anti-T-H antibodies resulted in a dramatic adhesion of neutrophils. Such an adhesion induced the oxidative burst of PMNs and a large increment in the release of T-H, as well as the release of the slightly faster migrating T-H form, which is normally retained intracellularly. CONCLUSIONS These results support the notion that, after the autoimmune response, the adhesion of neutrophils to cell-surface T-H contributes to the pathogenesis of tubulointerstitial nephritis, favoring a further accumulation of T-H in the interstitium and inducing the loss of cell integrity via reactive oxygen metabolites generated by activated neutrophils.
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Affiliation(s)
- D Cavallone
- Department of Experimental Pathology, University of Bologna, Italy
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