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Reynolds CJ, Gillen CM, Burke R, Tsering Y, Loucks E, Judd-Mole S, Dow JA, Romero MF. Drosophila ClC-c Is a Homolog of Human CLC-5 and a New Model for Dent Disease Type 1. KIDNEY360 2024; 5:414-426. [PMID: 38233994 PMCID: PMC11000744 DOI: 10.34067/kid.0000000000000352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 01/04/2024] [Indexed: 01/19/2024]
Abstract
Key Points Drosophila can be a model for Dent Disease type 1. Drosophila Clc-C mutations function similar to human CLC-5 Dent 1 mutations. Background Drosophila serve as exceptional alternative models for in vivo and ex vivo research and may provide an avenue for in-depth investigation for human ClC-5 and Dent disease type 1 (DD1). The Drosophila ClC-c (CG5284) has sequence homology with human ClC-5 and is hypothesized to encompass similar functional and phenotypical roles with ClC-5 and variants that cause DD1. Methods Ion transport function and activity of Drosophila ClC-c and homologous DD1 variants were assessed by voltage clamp electrophysiology. Membrane localization was demonstrated in Drosophila expressing a GFP-labeled construct of ClC-c. Genetic expression of an RNAi against ClC-c mRNA was used to generate a knockdown fly that serves as a DD1 disease model. Tubule secretion of cations and protein were assessed, as well as the crystal formation in the Malpighian tubules. Results Voltage clamp experiments demonstrate that ClC-c is voltage-gated with Cl−-dependent and pH-sensitive currents. Inclusion of homologous DD1 mutations pathogenic variants (S393L, R494W, and Q777X) impairs ClC-c ion transport activity. In vivo expression of ClC-c-eGFP in Malpighian tubules reveals that the membrane transporter localizes to the apical membrane and nearby cytosolic regions. RNAi knockdown of ClC-c (48% decreased mRNA expression) causes increased secretion of both urinary protein and Ca2+ and increased occurrence of spontaneous tubule crystals. Conclusions Drosophila ClC-c shows orthologous function and localization to human ClC-5. Thus, Drosophila and ClC-c regulation may be useful for future investigations of Cl− transport, Ca2+ homeostasis, and urinary protein loss in DD1.
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Affiliation(s)
- Carmen J. Reynolds
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine & Science, Rochester, Minnesota
| | | | - Richard Burke
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Yula Tsering
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine & Science, Rochester, Minnesota
- University of Minnesota-Rochester, Rochester, Minnesota
| | - Emi Loucks
- Department of Biology, Kenyon College, Gambier, Ohio
| | - Sebastian Judd-Mole
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Julian A.T. Dow
- School of Molecular Biosciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Michael F. Romero
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine & Science, Rochester, Minnesota
- Nephrology and Hypertension, Mayo Clinic College of Medicine & Science, Rochester, Minnesota
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2
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Kalmár T, Jakab D, Maróti Z, Lakatos O, Vas T, Bereczki C, Iványi B. The Apical Endocytic-Lysosomal Apparatus in CLCN5 Mutations with Phenotypic-Genotypic Correlations in Three Cases. Int J Mol Sci 2024; 25:966. [PMID: 38256038 PMCID: PMC10815395 DOI: 10.3390/ijms25020966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Dent disease type 1 is characterized by pathogenic CLCN5 gene variants and impaired receptor-mediated endocytosis in proximal tubules. However, mutation-related abnormalities in proximal tubules have not yet been described. Here, we present three patients with CLCN5 alterations and distinct morphological changes of the apical endocytic-lysosomal apparatus. The proximal tubular ultrastructure was investigated in kidney biopsy samples of three boys genotyped for non-nephrotic proteinuria. Controls: seven patients with nephrotic-range glomerular proteinuria. The genotyping findings revealed an already-known missense mutation in one patient and hitherto undescribed frameshift variants in two patients. Low-molecular-weight proteinuria, focal global glomerulosclerosis, proximal tubular changes, and tubular calcium deposits characterized each case. Three subsets of proximal tubular cells were observed: those without any abnormality, those with aplasia of apical endocytic-lysosomal apparatus and shrinkage of cells, and those with hypoplasia of apical endocytic apparatus, accumulation of proteinaceous substance in dysmorphic lysosomes, and dysmorphic mitochondria. The distribution of subsets varied from patient to patient. In one patient with a frameshift variant, an oxidative stress-like injury of proximal tubular cells and podocytes accompanied the above-mentioned alterations. Focal aplasia/hypoplasia of apical endocytic apparatus and subsequent changes in cytoplasmic organelles characterized proximal tubules in the CLCN5 pathogenic variants.
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Affiliation(s)
- Tibor Kalmár
- Department of Pediatrics, Albert Szent-Györgyi Medical School and Health Center, University of Szeged, 6720 Szeged, Hungary; (D.J.); (Z.M.); (C.B.)
| | - Dániel Jakab
- Department of Pediatrics, Albert Szent-Györgyi Medical School and Health Center, University of Szeged, 6720 Szeged, Hungary; (D.J.); (Z.M.); (C.B.)
| | - Zoltán Maróti
- Department of Pediatrics, Albert Szent-Györgyi Medical School and Health Center, University of Szeged, 6720 Szeged, Hungary; (D.J.); (Z.M.); (C.B.)
| | - Orsolya Lakatos
- Department of Pediatrics, University of Pécs, 7624 Pécs, Hungary;
| | - Tibor Vas
- Department of Internal Medicine, University of Pécs, 7624 Pécs, Hungary;
| | - Csaba Bereczki
- Department of Pediatrics, Albert Szent-Györgyi Medical School and Health Center, University of Szeged, 6720 Szeged, Hungary; (D.J.); (Z.M.); (C.B.)
| | - Béla Iványi
- Institute of Pathology, Albert Szent-Györgyi Medical School and Health Center, University of Szeged, 6720 Szeged, Hungary;
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3
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Gianesello L, Del Prete D, Ceol M, Priante G, Calò LA, Anglani F. From protein uptake to Dent disease: An overview of the CLCN5 gene. Gene 2020; 747:144662. [PMID: 32289351 DOI: 10.1016/j.gene.2020.144662] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/07/2020] [Indexed: 12/12/2022]
Abstract
Proteinuria is a well-known risk factor, not only for renal disorders, but also for several other problems such as cardiovascular diseases and overall mortality. In the kidney, the chloride channel Cl-/H+ exchanger ClC-5 encoded by the CLCN5 gene is actively involved in preventing protein loss. This action becomes evident in patients suffering from the rare proximal tubulopathy Dent disease because they carry a defective ClC-5 due to CLCN5 mutations. In fact, proteinuria is the distinctive clinical sign of Dent disease, and mainly involves the loss of low-molecular-weight proteins. The identification of CLCN5 disease-causing mutations has greatly improved our understanding of ClC-5 function and of the ClC-5-related physiological processes in the kidney. This review outlines current knowledge regarding the CLCN5 gene and its protein product, providing an update on ClC-5 function in tubular and glomerular cells, and focusing on its relationship with proteinuria and Dent disease.
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Affiliation(s)
- Lisa Gianesello
- Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology Unit, Department of Medicine - DIMED, University of Padua, Padua, Italy.
| | - Dorella Del Prete
- Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology Unit, Department of Medicine - DIMED, University of Padua, Padua, Italy.
| | - Monica Ceol
- Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology Unit, Department of Medicine - DIMED, University of Padua, Padua, Italy.
| | - Giovanna Priante
- Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology Unit, Department of Medicine - DIMED, University of Padua, Padua, Italy.
| | - Lorenzo Arcangelo Calò
- Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology Unit, Department of Medicine - DIMED, University of Padua, Padua, Italy.
| | - Franca Anglani
- Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology Unit, Department of Medicine - DIMED, University of Padua, Padua, Italy.
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4
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Chang MH, Brown MR, Liu Y, Gainullin VG, Harris PC, Romero MF, Lieske JC. Cl - and H + coupling properties and subcellular localizations of wildtype and disease-associated variants of the voltage-gated Cl -/H + exchanger ClC-5. J Biol Chem 2020; 295:1464-1473. [PMID: 31852738 PMCID: PMC7008381 DOI: 10.1074/jbc.ra119.011366] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/09/2019] [Indexed: 02/06/2023] Open
Abstract
Dent disease 1 (DD1) is caused by mutations in the CLCN5 gene encoding a voltage-gated electrogenic nCl-/H+ exchanger ClC-5. Using ion-selective microelectrodes and Xenopus oocytes, here we studied Cl-/H+ coupling properties of WT ClC-5 and four DD1-associated variants (S244L, R345W, Q629*, and T657S), along with trafficking and localization of ClC-5. WT ClC-5 had a 2Cl-/H+ exchange ratio at a Vh of +40 mV with a [Cl-]out of 104 mm, but the transport direction did not reverse with a [Cl-]out of 5 mm, indicating that ClC-5-mediated exchange of two Cl- out for one H+ in is not permissible. We hypothesized that ClC-5 and H+-ATPase are functionally coupled during H+-ATPase-mediated endosomal acidification, crucial for ClC-5 activation by depolarizing endosomes. ClC-5 transport that provides three net negative charges appeared self-inhibitory because of ClC-5's voltage-gated properties, but shunt conductance facilitated further H+-ATPase-mediated endosomal acidification. Thus, an on-and-off "burst" of ClC-5 activity was crucial for preventing Cl- exit from endosomes. The subcellular distribution of the ClC-5:S244L variant was comparable with that of WT ClC-5, but the variant had a much slower Cl- and H+ transport and displayed an altered stoichiometry of 1.6:1. The ClC-5:R345W variant exhibited slightly higher Cl-/H+ transport than ClC-5:S244L, but co-localized with early endosomes, suggesting decreased ClC-5:R345W membrane trafficking is perhaps in a fully functional form. The truncated ClC-5:Q629* variant displayed the lowest Cl-/H+ exchange and was retained in the endoplasmic reticulum and cis-Golgi, but not in early endosomes, suggesting the nonsense mutation affects ClC-5 maturation and trafficking.
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Affiliation(s)
- Min-Hwang Chang
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905; O'Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, Minnesota 55905.
| | - Matthew R Brown
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905; Wayne State University, Detroit, Michigan 48202
| | - Yiran Liu
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905; University of Michigan, Ann Arbor, Michigan 48109
| | - Vladimir G Gainullin
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905; Department of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Peter C Harris
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905; Department of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Michael F Romero
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905; O'Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, Minnesota 55905; Department of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - John C Lieske
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905; O'Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, Minnesota 55905; Department of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
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Gianesello L, Ceol M, Bertoldi L, Terrin L, Priante G, Murer L, Peruzzi L, Giordano M, Paglialonga F, Cantaluppi V, Musetti C, Valle G, Del Prete D, Anglani F. Genetic Analyses in Dent Disease and Characterization of CLCN5 Mutations in Kidney Biopsies. Int J Mol Sci 2020; 21:ijms21020516. [PMID: 31947599 PMCID: PMC7014080 DOI: 10.3390/ijms21020516] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 11/16/2022] Open
Abstract
Dent disease (DD), an X-linked renal tubulopathy, is mainly caused by loss-of-function mutations in CLCN5 (DD1) and OCRL genes. CLCN5 encodes the ClC-5 antiporter that in proximal tubules (PT) participates in the receptor-mediated endocytosis of low molecular weight proteins. Few studies have analyzed the PT expression of ClC-5 and of megalin and cubilin receptors in DD1 kidney biopsies. About 25% of DD cases lack mutations in either CLCN5 or OCRL genes (DD3), and no other disease genes have been discovered so far. Sanger sequencing was used for CLCN5 gene analysis in 158 unrelated males clinically suspected of having DD. The tubular expression of ClC-5, megalin, and cubilin was assessed by immunolabeling in 10 DD1 kidney biopsies. Whole exome sequencing (WES) was performed in eight DD3 patients. Twenty-three novel CLCN5 mutations were identified. ClC-5, megalin, and cubilin were significantly lower in DD1 than in control biopsies. The tubular expression of ClC-5 when detected was irrespective of the type of mutation. In four DD3 patients, WES revealed 12 potentially pathogenic variants in three novel genes (SLC17A1, SLC9A3, and PDZK1), and in three genes known to be associated with monogenic forms of renal proximal tubulopathies (SLC3A, LRP2, and CUBN). The supposed third Dent disease-causing gene was not discovered.
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Affiliation(s)
- Lisa Gianesello
- Laboratory of Histomorphology and Molecular Biology of the Kidney, Clinical Nephrology, Department of Medicine—DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (M.C.); (L.T.); (G.P.); (D.D.P.)
| | - Monica Ceol
- Laboratory of Histomorphology and Molecular Biology of the Kidney, Clinical Nephrology, Department of Medicine—DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (M.C.); (L.T.); (G.P.); (D.D.P.)
| | - Loris Bertoldi
- CRIBI Biotechnology Centre, University of Padua, 35131 Padua, Italy; (L.B.); (G.V.)
| | - Liliana Terrin
- Laboratory of Histomorphology and Molecular Biology of the Kidney, Clinical Nephrology, Department of Medicine—DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (M.C.); (L.T.); (G.P.); (D.D.P.)
| | - Giovanna Priante
- Laboratory of Histomorphology and Molecular Biology of the Kidney, Clinical Nephrology, Department of Medicine—DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (M.C.); (L.T.); (G.P.); (D.D.P.)
| | - Luisa Murer
- Pediatric Nephrology, Dialysis and Transplant Unit, Department of Women’s and Children’s Health, Padua University Hospital, 35128 Padua, Italy;
| | - Licia Peruzzi
- Pediatric Nephrology Unit, Regina Margherita Children’s Hospital, 10126 CDSS Turin, Italy;
| | - Mario Giordano
- Pediatric Nephrology Unit, University Hospital, P.O. Giovanni XXIII, 70126 Bari, Italy;
| | - Fabio Paglialonga
- Pediatric Nephrology, Dialysis and Transplant Unit, Fondazione IRCCS, Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy;
| | - Vincenzo Cantaluppi
- Nephrology and Kidney Transplantation Unit, Department of Translational Medicine, University of Piemonte Orientale (UPO), 28100 Novara, Italy; (V.C.); (C.M.)
| | - Claudio Musetti
- Nephrology and Kidney Transplantation Unit, Department of Translational Medicine, University of Piemonte Orientale (UPO), 28100 Novara, Italy; (V.C.); (C.M.)
| | - Giorgio Valle
- CRIBI Biotechnology Centre, University of Padua, 35131 Padua, Italy; (L.B.); (G.V.)
| | - Dorella Del Prete
- Laboratory of Histomorphology and Molecular Biology of the Kidney, Clinical Nephrology, Department of Medicine—DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (M.C.); (L.T.); (G.P.); (D.D.P.)
| | - Franca Anglani
- Laboratory of Histomorphology and Molecular Biology of the Kidney, Clinical Nephrology, Department of Medicine—DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (M.C.); (L.T.); (G.P.); (D.D.P.)
- CRIBI Biotechnology Centre, University of Padua, 35131 Padua, Italy; (L.B.); (G.V.)
- Correspondence: ; Tel.: +39-049-8212-155
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6
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Amnionless-mediated glycosylation is crucial for cell surface targeting of cubilin in renal and intestinal cells. Sci Rep 2018; 8:2351. [PMID: 29402915 PMCID: PMC5799345 DOI: 10.1038/s41598-018-20731-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/23/2018] [Indexed: 11/10/2022] Open
Abstract
Mutations in either cubilin (CUBN) or amnionless (AMN) genes cause Imerslund–Gräsbeck syndrome (IGS), a hereditary disease characterised by anaemia attributed to selective intestinal malabsorption of cobalamin and low-molecular weight proteinuria. Although cubilin protein does not have a transmembrane segment, it functions as a multi-ligand receptor by binding to the transmembrane protein, amnionless. We established a system to quantitatively analyse membrane targeting of the protein complex in cultured renal and intestinal cells and analysed the pathogenic mechanisms of mutations found in IGS patients. A novel CUBN mutation, several previously reported CUBN missense mutations and all previously reported AMN missense mutations resulted in endoplasmic reticulum (ER) retention and completely inhibited amnionless-dependent plasma membrane expression of cubilin. The ER retention of cubilin and amnionless was confirmed in renal proximal tubular cells of a patient with IGS. Notably, the interaction between cubilin and amnionless was not sufficient, but amnionless-mediated glycosylation of cubilin was necessary for their surface expression. Quantitative mass spectrometry and mutagenesis demonstrated that N-linked glycosylation of at least 4 residues of cubilin protein was required for its surface targeting. These results delineated the molecular mechanisms of membrane trafficking of cubilin in renal and intestinal cells.
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7
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Zaniew M, Mizerska-Wasiak M, Załuska-Leśniewska I, Adamczyk P, Kiliś-Pstrusińska K, Haliński A, Zawadzki J, Lipska-Ziętkiewicz BS, Pawlaczyk K, Sikora P, Ludwig M, Szczepańska M. Dent disease in Poland: what we have learned so far? Int Urol Nephrol 2017; 49:2005-2017. [PMID: 28815356 DOI: 10.1007/s11255-017-1676-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 08/07/2017] [Indexed: 12/13/2022]
Abstract
PURPOSE Dent disease (DD) is a rare tubulopathy characterized by proximal tubular dysfunction leading to chronic kidney disease (CKD). The aim of the study was to characterize patients with DD in Poland. METHODS A retrospective analysis of a national cohort with genetically confirmed diagnosis. RESULTS Of 24 males, all patients except one carried mutations in the CLCN5 gene; in one patient a mutation in the OCRL gene was disclosed. Molecular diagnosis was delayed 1 year on average (range 0-21 years). The most common features were tubular proteinuria (100%), hypercalciuria (87%), and nephrocalcinosis (56%). CKD (≤stage II) and growth deficiency were found in 45 and 22% of patients, respectively. Over time, a progression of CKD and persistence of growth impairment was noted. Subnephrotic and nephrotic proteinuria (20%) was found in most patients, but tubular proteinuria was assessed in only 67% of patients. In one family steroid-resistant nephrotic syndrome prompted a genetic testing, and reverse phenotyping. Five children (20%) underwent kidney biopsy, and two of them were treated with immunosuppressants. Hydrochlorothiazide and angiotensin-converting enzyme inhibitors were prescribed for a significant proportion of patients (42 and 37.5%, respectively), while supplemental therapy with phosphate, potassium, vitamin D (12.5% each), and alkali (4.2%) was insufficient, when compared to the percentages of patients requiring repletion. CONCLUSIONS We found CLCN5 mutations in the vast majority of Polish patients with DD. Proteinuria was the most constant finding; however, tubular proteins were not assessed commonly, likely leading to delayed molecular diagnosis and misdiagnosis in some patients. More consideration should be given to optimize the therapy.
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Affiliation(s)
- Marcin Zaniew
- Children's Hospital, ul. Krysiewicza 7/8, 61-825, Poznan, Poland. .,Polish Registry of Inherited Tubulopathies (POLtube), Polish Society of Pediatric Nephrology, Poznan, Poland.
| | | | - Iga Załuska-Leśniewska
- Department of Pediatrics, Nephrology and Hypertension, Medical University of Gdańsk, Gdańsk, Poland
| | - Piotr Adamczyk
- Department and Clinics of Pediatrics, SMDZ, Medical University of Silesia in Katowice, Zabrze, Poland
| | | | - Adam Haliński
- Department of Urology, Regional Hospital, Nowa Sól, Poland
| | - Jan Zawadzki
- Department of Nephrology and Kidney Transplantation, The Children's Memorial Health Institute, Warsaw, Poland
| | - Beata S Lipska-Ziętkiewicz
- Department of Biology and Medical Genetics, Clinical Genetics Unit, Medical University of Gdańsk, Gdańsk, Poland
| | - Krzysztof Pawlaczyk
- Department of Nephrology, Transplantology and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland
| | - Przemysław Sikora
- Polish Registry of Inherited Tubulopathies (POLtube), Polish Society of Pediatric Nephrology, Poznan, Poland.,Department of Pediatric Nephrology, Medical University of Lublin, Lublin, Poland
| | - Michael Ludwig
- Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Maria Szczepańska
- Department and Clinics of Pediatrics, SMDZ, Medical University of Silesia in Katowice, Zabrze, Poland
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Pyykkö I, Zou J, Schrott-Fischer A, Glueckert R, Kinnunen P. An Overview of Nanoparticle Based Delivery for Treatment of Inner Ear Disorders. Methods Mol Biol 2016; 1427:363-415. [PMID: 27259938 DOI: 10.1007/978-1-4939-3615-1_21] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Nanoparticles offer new possibilities for inner ear treatment as they can carry a variety of drugs, protein, and nucleic acids to inner ear. Nanoparticles are equipped with several functions such as targetability, immuno-transparency, biochemical stability, and ability to be visualized in vivo and in vitro. A group of novel peptides can be attached to the surface of nanoparticles that will enhance the cell entry, endosomal escape, and nuclear targeting. Eight different types of nanoparticles with different payload carrying strategies are available now. The transtympanic delivery of nanoparticles indicates that, depending on the type of nanoparticle, different migration pathways into the inner ear can be employed, and that optimal carriers can be designed according to the intended cargo. The use of nanoparticles as drug/gene carriers is especially attractive in conjunction with cochlear implantation or even as an inclusion in the implant as a drug/gene reservoir.
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Affiliation(s)
- Ilmari Pyykkö
- Department of Otolaryngology, University of Tampere and University Hospital of Tampere, Tampere, 33014, Finland. .,Hearing and Balance Research Unit, Field of Otolaryngology, School of Medicine, University of Tampere, Medisiinarinkatu 3, Tampere, 33520, Finland.
| | - Jing Zou
- BECS, Department of Biomedical Engineering and Computational Science, Aalto University, Aalto, 02150, Espoo, Finland
| | - Annelies Schrott-Fischer
- Department of Otolaryngology, Medical University of Innsbruck, Anichstrasse 35, Innsbruck, 6020, Austria
| | - Rudolf Glueckert
- Department of Otolaryngology, Medical University of Innsbruck, Anichstrasse 35, Innsbruck, 6020, Austria
| | - Paavo Kinnunen
- BECS, Department of Biomedical Engineering and Computational Science, Aalto University, Aalto, Finland
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Seki T, Asanuma K, Asao R, Nonaka K, Sasaki Y, Oliva Trejo JA, Kurosawa H, Hirayama Y, Horikoshi S, Tomino Y, Saito A. Significance of urinary full-length megalin in patients with IgA nephropathy. PLoS One 2014; 9:e114400. [PMID: 25502002 PMCID: PMC4264761 DOI: 10.1371/journal.pone.0114400] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 11/10/2014] [Indexed: 11/22/2022] Open
Abstract
Background and Objectives Megalin is highly expressed at the apical membranes of proximal tubular epithelial cells. A urinary full-length megalin (C-megalin) assay is linked to the severity of diabetic nephropathy in type 2 diabetes. This study examined the relationship between levels of urinary C-megalin and histological findings in adult patients with IgA nephropathy (IgAN). Design, Setting, Participants, & Measurements Urine samples voided in the morning on the day of renal biopsy were obtained from 73 patients with IgAN (29 men and 44 women; mean age, 33 years) and 5 patients with membranous nephropathy (MN). Renal pathologic variables were analyzed using the Oxford classification of IgAN, the Shigematsu classification and the Clinical Guidelines of IgAN in Japan. The levels of urinary C-megalin were measured by sandwich ELISA. Results Histological analysis based on the Oxford classification revealed that the levels of urinary C-megalin were correlated with mesangial hypercellularity in IgAN patients (OR = 1.76, 95% CI: 1.04–3.27, P<0.05). There was a significant correlation between the levels of urinary C-megalin and the severity of chronic extracapillary abnormalities according to the Shigematsu classification in IgAN patients (β = 0.33, P = 0.008). The levels of urinary C-megalin were significantly higher in all risk levels of IgAN patients requiring dialysis using the Clinical Guidelines of IgAN in Japan than in the control group. The levels of urinary C-megalin were significantly higher in the high risk and very high risk grades than in the low risk grade (P<0.05). The levels of urinary C-megalin were significantly higher in MN patients compared to the control group. Conclusions The levels of urinary C-megalin are associated with histological abnormalities in adult IgAN patients. There is a possibility that urinary C-megalin is an independent predictor of disease progression of IgAN. In addition, our results suggest that urinary C-megalin is a marker of glomerular abnormalities in various glomerular diseases as well as IgAN.
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Affiliation(s)
- Takuto Seki
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan; TMK project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Katsuhiko Asanuma
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan; TMK project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Rin Asao
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Kanae Nonaka
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan; TMK project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yu Sasaki
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | | | - Hiroyuki Kurosawa
- Reagents Development Department, Denka Seiken Co. Ltd., Niigata, Japan
| | - Yoshiaki Hirayama
- Reagents Development Department, Denka Seiken Co. Ltd., Niigata, Japan
| | - Satoshi Horikoshi
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Yasuhiko Tomino
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Akihiko Saito
- Department of Applied Molecular Medicine, Niigata University Graduate School of Medicine and Dental Sciences, Niigata, Japan
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Pusch M, Zifarelli G. ClC-5: Physiological role and biophysical mechanisms. Cell Calcium 2014; 58:57-66. [PMID: 25443653 DOI: 10.1016/j.ceca.2014.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/19/2014] [Accepted: 09/20/2014] [Indexed: 01/05/2023]
Abstract
Cl(-) transport in animal cells has fundamental physiological roles and it is mediated by a variety of protein families, one of them being the CLC family of ion channels and transporters. Besides their physiological relevance, CLC proteins show peculiar biophysical properties. This review will focus on a member of the CLC protein family, the endosomal Cl(-)/H(+) antiporter ClC-5. ClC-5 mutations cause Dent's disease, a renal syndrome due to defective protein reabsorption in the proximal tubule. This established the critical function of ClC-5 for endocytosis. However, our understanding of ClC-5's molecular role in endosomes and of its biophysical properties has proved elusive in spite of important progress achieved in the last two decades. Early models in which ClC-5 would provide a shunt conductance to enable efficient endosomal acidification conflicted with the antiport activity of ClC-5 that has more recently emerged. Currently, the physiological role of ClC-5 is hotly debated and its biophysical properties are still not fully understood.
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Affiliation(s)
- Michael Pusch
- Istituto di Biofisica, CNR, Via De Marini 6, 16149 Genoa, Italy
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De S, Kuwahara S, Saito A. The endocytic receptor megalin and its associated proteins in proximal tubule epithelial cells. MEMBRANES 2014; 4:333-55. [PMID: 25019425 PMCID: PMC4194038 DOI: 10.3390/membranes4030333] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 06/23/2014] [Accepted: 07/01/2014] [Indexed: 02/08/2023]
Abstract
Receptor-mediated endocytosis in renal proximal tubule epithelial cells (PTECs) is important for the reabsorption and metabolization of proteins and other substances, including carrier-bound vitamins and trace elements, in glomerular filtrates. Impairment of this endocytic process results in the loss of such substances and development of proteinuria, which is an important clinical indicator of kidney diseases and is also a risk marker for cardiovascular disease. Megalin, a member of the low-density lipoprotein receptor gene family, is a multiligand receptor expressed in the apical membrane of PTECs and plays a central role in the endocytic process. Megalin interacts with various intracellular adaptor proteins for intracellular trafficking and cooperatively functions with other membrane molecules, including the cubilin-amnionless complex. Evidence suggests that megalin and the cubilin-amnionless complex are involved in the uptake of toxic substances into PTECs, which leads to the development of kidney disease. Studies of megalin and its associated molecules will be useful for future development of novel strategies for the diagnosis and treatment of kidney diseases.
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Affiliation(s)
- Shankhajit De
- Division of Clinical Nephrology and Rheumatology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata 951-8510, Japan.
| | - Shoji Kuwahara
- Department of Applied Molecular Medicine, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata 951-8510, Japan.
| | - Akihiko Saito
- Department of Applied Molecular Medicine, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata 951-8510, Japan.
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Ogasawara S, Hosojima M, Kaseda R, Kabasawa H, Yamamoto-Kabasawa K, Kurosawa H, Sato H, Iino N, Takeda T, Suzuki Y, Narita I, Yamagata K, Tomino Y, Gejyo F, Hirayama Y, Sekine S, Saito A. Significance of urinary full-length and ectodomain forms of megalin in patients with type 2 diabetes. Diabetes Care 2012; 35:1112-8. [PMID: 22410816 PMCID: PMC3329833 DOI: 10.2337/dc11-1684] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Megalin, an endocytic receptor in proximal tubule cells, is involved in the mechanisms of albuminuria in diabetic nephropathy (DN). To develop efficient novel biomarkers associated with the pathogenesis of DN, we investigated urinary megalin excretion in type 2 diabetes. RESEARCH DESIGN AND METHODS Sandwich enzyme-linked immunosorbent assay systems were established with monoclonal antibodies against the NH(2) (amino [A]-megalin assay) and COOH (C-megalin assay) termini of megalin to analyze urinary forms of megalin in 68 patients with type 2 diabetes. RESULTS The A-megalin assay mainly detected a megalin ectodomain form in the soluble urinary fraction, whereas the C-megalin assay identified a full-length form in both soluble and insoluble fractions. Urinary C-megalin levels were significantly high in patients with normoalbuminuria, were elevated in line with increased albuminuria, and showed a better association with estimated glomerular filtration rate (eGFR) (<60 mL/min/1.73 m(2)) than did urinary albumin. In contrast, urinary A-megalin levels were increased in patients with normo- and microalbuminuria but not in those with macroalbuminuria. Urinary C-megalin levels were also positively associated with plasma inorganic phosphate and negatively with hemoglobin levels in those showing no features of bleeding and not taking vitamin D analogs, phosphate binders, or erythropoiesis-stimulating agents. CONCLUSIONS Urinary full-length megalin excretion as measured by the C-megalin assay is well associated with reduced eGFR and linked to the severity of DN, phosphate dysregulation, and anemia, whereas urinary excretion of megalin ectodomain as measured by the A-megalin assay may be associated with distinctive mechanisms of earlier DN in type 2 diabetes.
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Affiliation(s)
- Shinya Ogasawara
- Division of Clinical Nephrology and Rheumatology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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ClC-5 mutations associated with Dent's disease: a major role of the dimer interface. Pflugers Arch 2011; 463:247-56. [PMID: 22083641 DOI: 10.1007/s00424-011-1052-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 10/23/2011] [Accepted: 10/24/2011] [Indexed: 12/30/2022]
Abstract
Dent's disease is an X-linked recessive disorder affecting the proximal tubules. Mutations in the 2Cl(-)/H(+) exchanger ClC-5 gene CLCN5 are frequently associated with Dent's disease. Functional characterization of mutations of CLCN5 have helped to elucidate the physiopathology of Dent's disease and provided evidence that several different mechanisms underlie the ClC-5 dysfunction in Dent's disease. Modeling studies indicate that many CLCN5 mutations are located at the interface between the monomers of ClC-5, demonstrating that this protein region plays an important role in Dent's disease. On the basis of functional data, CLCN5 mutations can be divided into three different classes. Class 1 mutations impair processing and folding, and as a result, the ClC-5 mutants are retained within the endoplasmic reticulum and targeted for degradation by quality control mechanisms. Class 2 mutations induce a delay in protein processing and reduce the stability of ClC-5. As a consequence, the cell surface expression and currents of the ClC-5 mutants are lower. Class 3 mutations do not alter the trafficking of ClC-5 to the cell surface and early endosomes but induce altered electrical activity. Here, we discuss the functional consequences of the three classes of CLCN5 mutations on ClC-5 structure and function.
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Bu X, Zhou Y, Zhang H, Qiu W, Chen L, Cao H, Fang L, Wen P, Tan R, Yang J. Systemic administration of naked plasmid encoding HGF attenuates puromycin aminonucleoside-induced damage of murine glomerular podocytes. Am J Physiol Renal Physiol 2011; 301:F784-92. [PMID: 21775482 DOI: 10.1152/ajprenal.00210.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Podocyte injury is considered to play important roles in the pathogenesis of human glomerular disease. There is accumulating evidence suggesting that hepatocyte growth factor (HGF) elicits preventive activity for glomerular cells in animal models of chronic renal diseases. In this study, we demonstrated that delivery of a naked plasmid vector encoding the human HGF gene into mice by a hydrodynamic-based in vivo gene transfection approach markedly reduced proteinuria and attenuated podocyte injury in a mouse model induced by puromycin aminonucleoside (PAN) injection. Systemic administration by rapid injection via the tail vein of a naked plasmid containing HGF cDNA driven under a cytomegalovirus promoter (pCMV-HGF) produced a remarkable level of human HGF protein in the circulation. Tissue distribution studies suggested that the kidney expressed a high level of the HGF transgene. Meanwhile, compared with tubules and interstitium, a higher level of exogenous HGF protein was detected in the glomeruli. Administration of pCMV-HGF dramatically abated the urine albumin excretion and podocyte injury in PAN nephropathy in mice. Exogenous expression of HGF produced evidently beneficial effects, leading to restoration of Wilms' tumor-1 (WT1) and α-actinin-4 expression and attenuation of ultrastructural damage of the podocytes. In vitro, HGF not only restored WT1 and α-actinin-4 expression but also inhibited albumin leakage of podocytes incubated with PAN in a Transwell culture chamber. These results suggest that HGF might provide a novel strategy for amelioration of podocyte injury.
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Affiliation(s)
- Xuan Bu
- Center of Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, China
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Novel techniques and newer markers for the evaluation of “proximal tubular dysfunction”. Int Urol Nephrol 2011; 43:1107-15. [DOI: 10.1007/s11255-011-9914-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Accepted: 02/07/2011] [Indexed: 10/18/2022]
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Molecular mechanisms of receptor-mediated endocytosis in the renal proximal tubular epithelium. J Biomed Biotechnol 2010; 2010:403272. [PMID: 20011067 PMCID: PMC2789548 DOI: 10.1155/2010/403272] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2009] [Accepted: 09/14/2009] [Indexed: 11/17/2022] Open
Abstract
Receptor-mediated endocytosis is a pivotal function of renal proximal tubule epithelial cells (PTECs) to reabsorb and metabolize substantial amounts of proteins and other substances in glomerular filtrates. The function accounts for the conservation of nutrients, including carrier-bound vitamins and trace elements, filtered by glomeruli. Impairment of the process results in a loss of such substances and development of proteinuria, an important clinical sign of kidney disease and a risk marker for cardiovascular disease. Megalin is a multiligand endocytic receptor expressed at clathrin-coated pits of PTEC, playing a central role in the process. Megalin cooperates with various membrane molecules and interacts with many intracellular adaptor proteins for endocytic trafficking. Megalin is also involved in signaling pathways in the cells. Megalin-mediated endocytic overload leads to damage of PTEC. Further studies are needed to elucidate the mechanism of megalin-mediated endocytosis and develop strategies for preventing the damage of PTEC.
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Novel CLCN5 mutations in patients with Dent’s disease result in altered ion currents or impaired exchanger processing. Kidney Int 2009; 76:999-1005. [DOI: 10.1038/ki.2009.305] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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