1
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Wang Y, Xu L, Zhang Y, Fu H, Gao L, Guan Y, Gu W, Sun J, Chen X, Yang F, Lai E, Wang J, Jin Y, Kou Z, Qiu X, Mao J, Hu L. Dent disease 1-linked novel CLCN5 mutations result in aberrant location and reduced ion currents. Int J Biol Macromol 2024; 257:128564. [PMID: 38061527 DOI: 10.1016/j.ijbiomac.2023.128564] [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: 06/13/2023] [Revised: 11/12/2023] [Accepted: 11/30/2023] [Indexed: 12/17/2023]
Abstract
Dent disease is a rare renal tubular disease with X-linked recessive inheritance characterized by low molecular weight proteinuria (LMWP), hypercalciuria, and nephrocalcinosis. Mutations disrupting the 2Cl-/1H+ exchange activity of chloride voltage-gated channel 5 (CLCN5) have been causally linked to the most common form, Dent disease 1 (DD1), although the pathophysiological mechanisms remain unclear. Here, we conducted the whole exome capture sequencing and bioinformatics analysis within our DD1 cohort to identify two novel causal mutations in CLCN5 (c.749 G > A, p. G250D, c.829 A > C, p. T277P). Molecular dynamics simulations of ClC-5 homology model suggested that these mutations potentially may induce structural changes, destabilizing ClC-5. Overexpression of variants in vitro revealed aberrant subcellular localization in the endoplasmic reticulum (ER), significant accumulation of insoluble aggregates, and disrupted ion transport function in voltage clamp recordings. Moreover, human kidney-2 (HK-2) cells overexpressing either G250D or T277P displayed higher cell-substrate adhesion, migration capability but reduced endocytic function, as well as substantially altered transcriptomic profiles with G250D resulting in stronger deleterious effects. These cumulative findings supported pathogenic role of these ClC-5 mutations in DD1 and suggested a cellular mechanism for disrupted renal function in Dent disease patients, as well as a potential target for diagnostic biomarker or therapeutic strategy development.
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Affiliation(s)
- Yan Wang
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Lizhen Xu
- Department of Biophysics, and Kidney Disease Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Ying Zhang
- Eye Center of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Haidong Fu
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Langping Gao
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Yuelin Guan
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Weizhong Gu
- Department of Pathology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Jingmiao Sun
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Xiangjun Chen
- Eye Center of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou 310020, China
| | - Fan Yang
- Department of Biophysics, and Kidney Disease Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - EnYin Lai
- Department of Physiology School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou, China
| | - Jingjing Wang
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Yanyan Jin
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Ziqi Kou
- Institute for Brain Research and Rehabilitation, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, China
| | - Xingyu Qiu
- Department of Physiology School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianhua Mao
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China.
| | - Lidan Hu
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China.
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2
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Bouhamdani N, Comeau D, Turcotte S. A Compendium of Information on the Lysosome. Front Cell Dev Biol 2022; 9:798262. [PMID: 34977038 PMCID: PMC8714965 DOI: 10.3389/fcell.2021.798262] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/02/2021] [Indexed: 12/16/2022] Open
Abstract
For a long time, lysosomes were considered as mere waste bags for cellular constituents. Thankfully, studies carried out in the past 15 years were brimming with elegant and crucial breakthroughs in lysosome research, uncovering their complex roles as nutrient sensors and characterizing them as crucial multifaceted signaling organelles. This review presents the scientific knowledge on lysosome physiology and functions, starting with their discovery and reviewing up to date ground-breaking discoveries highlighting their heterogeneous functions as well as pending questions that remain to be answered. We also review the roles of lysosomes in anti-cancer drug resistance and how they undergo a series of molecular and functional changes during malignant transformation which lead to tumor aggression, angiogenesis, and metastases. Finally, we discuss the strategy of targeting lysosomes in cancer which could lead to the development of new and effective targeted therapies.
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Affiliation(s)
- Nadia Bouhamdani
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada.,Dr. Georges-L. Dumont University Hospital Centre, Clinical Research Sector, Vitalité Health Network, Moncton, NB, Canada.,Atlantic Cancer Research Institute, Moncton, NB, Canada
| | - Dominique Comeau
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada.,Atlantic Cancer Research Institute, Moncton, NB, Canada
| | - Sandra Turcotte
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada.,Atlantic Cancer Research Institute, Moncton, NB, Canada
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3
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Azouz AA, Hanna DA, Abo-Saif AA, Anwar Shehata Messiha B. Interference with megalin expression/endocytic function by montelukast mitigates gentamicin nephrotoxicity: Downregulation of ClC-5 expression. Saudi Pharm J 2022; 30:150-161. [PMID: 35528850 PMCID: PMC9072701 DOI: 10.1016/j.jsps.2021.12.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/27/2021] [Indexed: 10/25/2022] Open
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4
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Jin YY, Huang LM, Quan XF, Mao JH. Dent disease: classification, heterogeneity and diagnosis. World J Pediatr 2021; 17:52-57. [PMID: 32248351 DOI: 10.1007/s12519-020-00357-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 03/05/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Dent disease is a rare tubulopathy characterized by manifestations of proximal tubular dysfunction, which occurs almost exclusively in males. It mainly presents symptoms in early childhood and may progress to end-stage renal failure between the 3rd and 5th decades of human life. According to its various genetic basis and to clinical signs and symptoms, researchers define two forms of Dent disease (Dent diseases 1 and 2) and suggest that these forms are produced by mutations in the CLCN5 and OCRL genes, respectively. Dent diseases 1 and 2 account for 60% and 15% of all Dent disease cases, and their genetic cause is generally understood. However, the genetic cause of the remaining 25% of Dent disease cases remains unidentified. DATA SOURCES All relevant peer-reviewed original articles published thus far have been screened out from PubMed and have been referenced. RESULTS Genetic testing has been used greatly to identify mutation types of CLCN5 and OCRL gene, and next-generation sequencing also has been used to identify an increasing number of unknown genotypes. Gene therapy may bring new hope to the treatment of Dent disease. The abuse of hormones and immunosuppressive agents for the treatment of Dent disease should be avoided to prevent unnecessary harm to children. CONCLUSIONS The current research progress in classification, genetic heterogeneity, diagnosis, and treatment of Dent disease reviewed in this paper enables doctors and researchers to better understand Dent disease and provides a basis for improved prevention and treatment.
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Affiliation(s)
- Yan-Yan Jin
- Department of Nephrology, National Clinical Research Center for Child Health, The Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou, 310006, China
| | - Li-Min Huang
- Department of Nephrology, National Clinical Research Center for Child Health, The Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou, 310006, China
| | - Xiao-Fang Quan
- Chigene (Beijing) Translational Medical Research Center Co. Ltd, E2 Biomedical Park, No. 88 Kechuang Sixth Ave, Yizhuang, Beijing, China
| | - Jian-Hua Mao
- Department of Nephrology, National Clinical Research Center for Child Health, The Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou, 310006, China.
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5
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Tang X, Brown MR, Cogal AG, Gauvin D, Harris PC, Lieske JC, Romero MF, Chang MH. Functional and transport analyses of CLCN5 genetic changes identified in Dent disease patients. Physiol Rep 2016; 4:4/8/e12776. [PMID: 27117801 PMCID: PMC4848727 DOI: 10.14814/phy2.12776] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 03/29/2016] [Indexed: 12/18/2022] Open
Abstract
Dent disease type 1, an X‐linked inherited kidney disease is caused by mutations in electrogenic Cl−/H+ exchanger, ClC‐5. We functionally studied the most frequent mutation (S244L) and two mutations recently identified in RKSC patients, Q629X and R345W. We also studied T657S, which has a high minor‐allele frequency (0.23%) in the African‐American population, was published previously as pathogenic to cause Dent disease. The transport properties of CLC‐5 were electrophysiologically characterized. WT and ClC‐5 mutant currents were inhibited by pH 5.5, but not affected by an alkaline extracellular solution (pH 8.5). The T657S and R345W mutations showed the same anion selectivity sequence as WT ClC‐5 (SCN−>NO3−≈Cl−>Br−>I−). However, the S244L and Q629X mutations abolished this anion conductance sequence. Cell surface CLC‐5 expression was quantified using extracellular HA‐tagged CLC‐5 and a chemiluminescent immunoassay. Cellular localization of eGFP‐tagged CLC‐5 proteins was also examined in HEK293 cells with organelle‐specific fluorescent probes. Functional defects of R345W and Q629X mutations were caused by the trafficking of the protein to the plasma membrane since proteins were mostly retained in the endoplasmic reticulum, and mutations showed positive correlations between surface expression and transport function. In contrast, although the S244L transport function was significantly lower than WT, cell surface, early endosome, and endoplasmic reticulum expression was equal to that of WT CLC‐5. Function and trafficking of T657S was equivalent to the WT CLC‐5 suggesting this is a benign variant rather than pathogenic. These studies demonstrate the useful information that can be gained by detailed functional studies of mutations predicted to be pathogenic.
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Affiliation(s)
- Xiaojing Tang
- O'Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, Minnesota Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota Division of Nephrology, Shanghai Changzheng Hospital Second Military Medical University, Shanghai, China
| | - Matthew R Brown
- O'Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, Minnesota Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota Wayne State University, Detroit, Michigan
| | - Andrea G Cogal
- Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Daniel Gauvin
- O'Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, Minnesota Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Peter C Harris
- Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - John C Lieske
- O'Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, Minnesota Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Michael F Romero
- O'Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, Minnesota Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Min-Hwang Chang
- O'Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, Minnesota Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota
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6
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Armanet N, Metay C, Brisset S, Deschenes G, Pineau D, Petit FM, Di Rocco F, Goossens M, Tachdjian G, Labrune P, Tosca L. Double Xp11.22 deletion including SHROOM4 and CLCN5 associated with severe psychomotor retardation and Dent disease. Mol Cytogenet 2015; 8:8. [PMID: 25670966 PMCID: PMC4322561 DOI: 10.1186/s13039-015-0107-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/08/2015] [Indexed: 11/23/2022] Open
Abstract
Background Here we report the clinical and molecular characterization of two Xp11.22 deletions including SHROOM4 and CLCN5 genes. These deletions appeared in the same X chromosome of the same patient. Results The patient is a six-year-old boy who presented hydrocephalus, severe psychomotor and growth retardation, facial dysmorphism and renal proximal tubulopathy associated with low-molecular-weight proteinuria, hypercalciuria, hyperaminoaciduria, hypophosphatemia and hyperuricemia. Standard and high resolution karyotypes showed a 46,XY formula. Array-CGH revealed two consecutive cryptic deletions in the region Xp11.22, measuring respectively 148 Kb and 2.6 Mb. The two deletions were inherited from the asymptomatic mother. Conclusions Array-CGH allowed us to determine candidate genes in the deleted region. The disruption and partial loss of CLCN5 confirmed the diagnostic of Dent disease for this patient. Moreover, the previously described involvement of SHROOM4 in neuronal development is discussed.
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Affiliation(s)
- Narjes Armanet
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| | - Corinne Metay
- Plateforme de Génomique IMRB 955, Hôpital Henri Mondor, Créteil, F-94010 France
| | - Sophie Brisset
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| | - Georges Deschenes
- Service de Néphrologie pédiatrique, Hôpital Robert Debré, Paris, F-75935 France
| | - Dominique Pineau
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France
| | - François M Petit
- Laboratoire de Génétique Moléculaire, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, Clamart, F-92140 France
| | - Federico Di Rocco
- Service de Neurochirurgie pédiatrique, Hôpital Necker Enfants Malades, Clamart, F-75015 France
| | - Michel Goossens
- Plateforme de Génomique IMRB 955, Hôpital Henri Mondor, Créteil, F-94010 France.,Université Paris Est, Créteil, F-94010 France
| | - Gérard Tachdjian
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| | - Philippe Labrune
- Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France.,Service de Pédiatrie, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, Clamart, F-92140 France
| | - Lucie Tosca
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
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7
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Dahlin A, Wittwer M, de la Cruz M, Woo JM, Bam R, Scharen-Guivel V, Flaherty J, Ray AS, Cihlar T, Gupta SK, Giacomini KM. A pharmacogenetic candidate gene study of tenofovir-associated Fanconi syndrome. Pharmacogenet Genomics 2015; 25:82-92. [PMID: 25485598 PMCID: PMC4331349 DOI: 10.1097/fpc.0000000000000110] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Tenofovir disoproxil fumarate (TDF) is a widely used antiretroviral agent with favorable efficacy, safety, and tolerability profiles. However, renal adverse events, including the rare Fanconi syndrome (FS), may occur in a small subset of patients treated for HIV infections. OBJECTIVES The aim of this study was to identify genetic variants that may be associated with TDF-associated FS (TDF-FS). METHODS DNA samples collected from 19 cases with TDF-FS and 36 matched controls were sequenced, and genetic association studies were conducted on eight candidate genes: ATP-binding cassette (ABC) transporters ABCC2 (MRP2) and ABCC4 (MRP4), solute carrier family members SLC22A6 (OAT1) and SLC22A8 (OAT3), adenylate kinases 2 (AK2) and 4 (AK4), chloride transporter CIC-5 CLCN5, and Lowe syndrome protein OCRL. The functional effects of a single nucleotide polymorphism (SNP) predicted to alter the transport of tenofovir were then investigated in cells expressing an identified variant of ABCC4. RESULTS The case group showed a trend toward a higher proportion of rare alleles. Six SNPs in ABCC2 (three SNPs), ABCC4 (one SNP), and OCRL (two SNPs) were associated with TDF-FS case status; however, this association did not remain significant after correction for multiple testing. Six SNPs, present in OCRL (four SNPs) and ABCC2 (two SNPs), were significantly associated with increased serum creatinine levels in the cases, and this association remained significant after multiple test correction (P < 2 × 10). One synonymous SNP in ABCC2 (rs8187707, P = 2.10 × 10, β = -73.3 ml/min/1.73 m(2)) was also significantly associated with the decreased estimated glomerular filtration rate of creatinine among cases. However, these results were driven by rare SNPs present in a small number of severely affected cases. Finally, a previously uncharacterized, nonsynonymous SNP, rs11568694, that was predicted to alter MRP4 function had no significant effect on tenofovir cellular accumulation in vitro. CONCLUSION Although no single predictive genetic marker for the development of TDF-FS was identified, the findings from our study suggest that rare variants in multiple genes involved in the renal handling of tenofovir, and/or renal cell homeostasis, may be associated with increased susceptibility to TDF-FS.
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Affiliation(s)
- Amber Dahlin
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California 94158, United States
| | - Matthias Wittwer
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California 94158, United States
| | - Melanie de la Cruz
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California 94158, United States
- Genomics Core Facility, Institute for Human Genetics, San Francisco, CA 94143, United States
| | - Jonathan M. Woo
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California 94158, United States
- Genomics Core Facility, Institute for Human Genetics, San Francisco, CA 94143, United States
| | - Rujuta Bam
- Gilead Sciences, Inc., Foster City, CA, 94404, United States
| | | | - John Flaherty
- Gilead Sciences, Inc., Foster City, CA, 94404, United States
| | - Adrian S. Ray
- Gilead Sciences, Inc., Foster City, CA, 94404, United States
| | - Tomas Cihlar
- Gilead Sciences, Inc., Foster City, CA, 94404, United States
| | - Samir K. Gupta
- Division of Infectious Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Kathleen M. Giacomini
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California 94158, United States
- Institute of Human Genetics, University of California, San Francisco, San Francisco, California, 94143, United States
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8
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Greenlee MM, Mitzelfelt JD, Duke BJ, Al-Khalili O, Bao HF, Eaton DC. Prolactin stimulates sodium and chloride ion channels in A6 renal epithelial cells. Am J Physiol Renal Physiol 2015; 308:F697-705. [PMID: 25587116 DOI: 10.1152/ajprenal.00270.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 01/07/2015] [Indexed: 11/22/2022] Open
Abstract
Many hormonal pathways contribute to the regulation of renal epithelial sodium channel (ENaC) function, a key process for maintaining blood volume and controlling blood pressure. In the present study, we examined whether the peptide hormone prolactin (PRL) regulates ENaC function in renal epithelial cells (A6). Basolateral application of several different concentrations of PRL dramatically stimulated the transepithelial current in A6 cells, increasing both amiloride-sensitive (ENaC) and amiloride-insensitive currents. Using cell-attached patch clamp, we determined that PRL increased both the number (N) and open probability (Po) of ENaC present in the apical membrane. Inhibition of PKA with H-89 abolished the effect of PRL on amiloride-sensitive and insensitive transepithelial currents and eliminated the increase in ENaC NPo with PRL exposure. PRL also increased cAMP in A6 cells, consistent with signaling through the cAMP-dependent PKA pathway. We also identified that PRL induced activity of a 2-pS anion channel with outward rectification, electrophysiological properties consistent with ClC4 or ClC5. RT-PCR only detected ClC4, but not ClC5 transcripts. Here, we show for the first time that PRL activates sodium and chloride transport in renal epithelial cells via ENaC and ClC4.
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Affiliation(s)
- Megan M Greenlee
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | | | - Billie Jeanne Duke
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Otor Al-Khalili
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Hui-Fang Bao
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
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9
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Denton JS, Pao AC, Maduke M. Novel diuretic targets. Am J Physiol Renal Physiol 2013; 305:F931-42. [PMID: 23863472 PMCID: PMC3798746 DOI: 10.1152/ajprenal.00230.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 07/12/2013] [Indexed: 01/11/2023] Open
Abstract
As the molecular revolution continues to inform a deeper understanding of disease mechanisms and pathways, there exist unprecedented opportunities for translating discoveries at the bench into novel therapies for improving human health. Despite the availability of several different classes of antihypertensive medications, only about half of the 67 million Americans with hypertension manage their blood pressure appropriately. A broader selection of structurally diverse antihypertensive drugs acting through different mechanisms would provide clinicians with greater flexibility in developing effective treatment regimens for an increasingly diverse and aging patient population. An emerging body of physiological, genetic, and pharmacological evidence has implicated several renal ion-transport proteins, or regulators thereof, as novel, yet clinically unexploited, diuretic targets. These include the renal outer medullary potassium channel, ROMK (Kir1.1), Kir4.1/5.1 potassium channels, ClC-Ka/b chloride channels, UTA/B urea transporters, the chloride/bicarbonate exchanger pendrin, and the STE20/SPS1-related proline/alanine-rich kinase (SPAK). The molecular pharmacology of these putative targets is poorly developed or lacking altogether; however, recent efforts by a few academic and pharmaceutical laboratories have begun to lessen this critical barrier. Here, we review the evidence in support of the aforementioned proteins as novel diuretic targets and highlight examples where progress toward developing small-molecule pharmacology has been made.
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Affiliation(s)
- Jerod S Denton
- T4208 Medical Center North, 1161 21st Ave. South, Nashville, TN 37232.
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10
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Slc26a11 is prominently expressed in the brain and functions as a chloride channel: expression in Purkinje cells and stimulation of V H⁺-ATPase. Pflugers Arch 2013; 465:1583-97. [PMID: 23733100 DOI: 10.1007/s00424-013-1300-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/13/2013] [Accepted: 05/14/2013] [Indexed: 02/07/2023]
Abstract
SLC26A11 (human)/Slc26a11 (mouse), also known as kidney brain anion transporter (KBAT), is a member of the SLC26 anion transporter family and shows abundant mRNA expression in the brain. However, its exact cellular distribution and subcellular localization in the brain and its functional identity and possible physiological roles remain unknown. Expression and immunostaining studies demonstrated that Slc26a11 is abundantly expressed in the cerebellum, with a predominant expression in Purkinje cells. Lower expression levels were detected in hippocampus, olfactory bulb, cerebral cortex, and subcortical structures. Patch clamp studies in HEK293 cells transfected with mouse cDNA demonstrated that Slc26a11 can function as a chloride channel that is active under basal conditions and is not regulated by calcium, forskolin, or co-expression with cystic fibrosis transmembrane regulator. Single and double immunofluorescent labeling studies demonstrated the localization of vacuolar (V) H⁺-ATPase and Slc26a11 (KBAT) in the plasma membrane in Purkinje cells. Functional studies in HEK293 cells indicated that transfection with Slc26a11 stimulated acid transport via endogenous V H⁺-ATPase. We conclude that Slc26a11 (KBAT) is prominently distributed in output neurons of various subcortical and cortical structures in the central nervous system, with specific expression in Purkinje cells and that it may operate as a chloride channel regulating acid translocation by H⁺-ATPase across the plasma membrane and in intracellular compartments.
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11
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Lippiat JD, Smith AJ. The CLC-5 2Cl(-)/H(+) exchange transporter in endosomal function and Dent's disease. Front Physiol 2012; 3:449. [PMID: 23226131 PMCID: PMC3510460 DOI: 10.3389/fphys.2012.00449] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 11/09/2012] [Indexed: 01/25/2023] Open
Abstract
CLC-5 plays a critical role in the process of endocytosis in the proximal tubule of the kidney and mutations that alter protein function are the cause of Dent's I disease. In this X-linked disorder impaired reabsorption results in the wasting of calcium and low molecular weight protein to the urine, kidney stones, and progressive renal failure. Several different ion-transporting and protein clustering roles have been proposed as the physiological function of CLC-5 in endosomal membranes. At the time of its discovery, nearly 20 years ago, it was understandably assumed to be a chloride channel similar to known members of the CLC family, such as CLC-1, suggesting that chloride transport by CLC-5 was critical for endosomal function. Since then CLC-5 was found instead to be a 2Cl−/H+ exchange transporter with voltage-dependent activity. Recent studies have determined that it is this coupled exchange of protons for chloride, and not just chloride transport, which is critical for endosomal and kidney function. This review discusses the recent ideas that describe how CLC-5 might function in endosomal membranes, the aspects that we still do not understand, and where controversies remain.
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Affiliation(s)
- Jonathan D Lippiat
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds Leeds, UK
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Ceol M, Tiralongo E, Baelde HJ, Vianello D, Betto G, Marangelli A, Bonfante L, Valente M, Della Barbera M, D’Angelo A, Anglani F, Del Prete D. Involvement of the tubular ClC-type exchanger ClC-5 in glomeruli of human proteinuric nephropathies. PLoS One 2012; 7:e45605. [PMID: 23029130 PMCID: PMC3454393 DOI: 10.1371/journal.pone.0045605] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 08/23/2012] [Indexed: 01/15/2023] Open
Abstract
UNLABELLED Glomerular protein handling mechanisms have received much attention in studies of nephrotic syndrome. Histopathological findings in renal biopsies from severely proteinuric patients support the likelihood of protein endocytosis by podocytes. ClC-5 is involved in the endocytosis of albumin in the proximal tubule. AIM To investigate whether ClC-5 is expressed in the glomerular compartment and whether it has a role in proteinuric nephropathies. ClC-5 expression was studied using Real-time PCR in manually- and laser-microdissected biopsies from patients with type 2 diabetes (n 37) and IgA nephropathy (n 10); in biopsies of membranous glomerulopathy (MG) (n 14) immunohistochemistry for ClC-5 (with morphometric analysis) and for WT1 was done. CONTROLS cortical tissue (n 23) obtained from unaffected parts of tumor-related nephrectomy specimens. RESULTS ClC-5 was expressed at glomerular level in all biopsies. Glomerular ClC-5 levels were significantly higher in diabetic nephropaty and MG at both mRNA and protein level (p<0.002; p<0.01). ClC-5 and WT1 double-staining analysis in MG showed that ClC-5 was localized in the podocytes. ClC-5 ultrastructural immunolocalization was demonstrated in podocytes foot processes. Our study is the first to demonstrate that ClC-5 is expressed in human podocytes. The ClC-5 overexpression found in biopsies of proteinuric patients suggests that proteinuria may play a part in its expression and that podocytes are likely to have a key role in albumin handling in proteinuric states.
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Affiliation(s)
- Monica Ceol
- Department of Medicine, Nephrology Unit and Kidney Histomorphology and Molecular Biology Laboratory, University of Padova, Padova, Italy
| | - Emilia Tiralongo
- Department of Medicine, Nephrology Unit and Kidney Histomorphology and Molecular Biology Laboratory, University of Padova, Padova, Italy
| | - Hans J. Baelde
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | - Daniela Vianello
- Department of Medicine, Nephrology Unit and Kidney Histomorphology and Molecular Biology Laboratory, University of Padova, Padova, Italy
| | | | - Annunziata Marangelli
- Department of Medicine, Nephrology Unit and Kidney Histomorphology and Molecular Biology Laboratory, University of Padova, Padova, Italy
| | - Luciana Bonfante
- Department of Medicine, Nephrology Unit and Kidney Histomorphology and Molecular Biology Laboratory, University of Padova, Padova, Italy
| | - Marialuisa Valente
- Department of Diagnostic Medical Science and Special Therapies, Institute of Pathological Anatomy, University of Padova, Padova, Italy
| | - Mila Della Barbera
- Department of Diagnostic Medical Science and Special Therapies, Institute of Pathological Anatomy, University of Padova, Padova, Italy
| | - Angela D’Angelo
- Department of Medicine, Nephrology Unit and Kidney Histomorphology and Molecular Biology Laboratory, University of Padova, Padova, Italy
| | - Franca Anglani
- Department of Medicine, Nephrology Unit and Kidney Histomorphology and Molecular Biology Laboratory, University of Padova, Padova, Italy
| | - Dorella Del Prete
- Department of Medicine, Nephrology Unit and Kidney Histomorphology and Molecular Biology Laboratory, University of Padova, Padova, Italy
- * E-mail:
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Li D, Zhang X, Li Z, Yang J, Pan J, Zhu X. Cryptococcus neoformans Ca(2+) homeostasis requires a chloride channel/antiporter Clc1 in JEC21, but not in H99. FEMS Yeast Res 2011; 12:69-77. [PMID: 22093100 DOI: 10.1111/j.1567-1364.2011.00763.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 10/18/2011] [Accepted: 11/09/2011] [Indexed: 01/15/2023] Open
Abstract
CLC-type chloride/proton antiporters are required for copper/iron homeostasis in fungi. A relationship between CLCs and Ca(2+) homeostasis has not been found before. Here we demonstrate the requirement of the antiporter CLC1 for Ca(2+) homeostasis/signaling in Cryptococcus neoformans. The deletion of CLC1 in JEC21 resulted in a mutant hypersensitive to cyclosporine A, an inhibitor of calcineurin. Intracellular Ca(2+) deficiency in the mutant Tx1 was confirmed with Fluo-3 staining epi-fluorescence microscopy. Tx1 failed to grow at elevated temperature and in SDS and displayed defects in cell wall integrity and cell separation. This defective phenotype is because of Ca(2+) deficiency that was restorable by exogenous Ca(2+) . In contrast, H99 CLC1 was dispensable for Ca(2+) homeostasis and had no comparable defective consequences if deleted, suggesting divergent roles of CLCs in Ca(2+) homeostasis. Distinct Ca(2+) homeostasis mechanisms may contribute the virulence difference between the two strains. This work reveals a novel action of CLC antiporters in fungi and may provide information as to the evolution of pathogenicity among cryptococcal strains.
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Affiliation(s)
- Dong Li
- National Key Program of Microbiology and Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
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Scott CC, Gruenberg J. Ion flux and the function of endosomes and lysosomes: pH is just the start: the flux of ions across endosomal membranes influences endosome function not only through regulation of the luminal pH. Bioessays 2011; 33:103-10. [PMID: 21140470 DOI: 10.1002/bies.201000108] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The ionic nature of endosomes varies considerably in character along the endocytic pathway. Counter-ion flux across the limiting membrane of endosomes has long been considered essential for full acidification and normal endosome/lysosomal function. The proximal functions of luminal ions, however, have been difficult to assess. The recent development of transgenic mice carrying mutations in the intracellular chloride channels (ClCs) has provided a tool to uncouple Cl(-) influx from endosomal acidification. Intriguingly, many of the defects of the endo-lysomal system attributed to aberrant pH persist in the Cl(-)-deficient mice implying a direct regulatory role for Cl(-) influx in endosome function. These observations may begin to explain the abundance of endosomal ion transporters, including ClCs, sodium-proton exchangers, two-pore channels and mucolipins, that have been localized to endo-lysosomes, and the extensive changes in luminal ion composition therein. In this review, we summarize what is known regarding the mediators of endosomal ion flux, and discuss the implications of changing ionic content on endo-lysosomal function.
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Affiliation(s)
- Cameron C Scott
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
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Role of the ubiquitin system in regulating ion transport. Pflugers Arch 2010; 461:1-21. [PMID: 20972579 DOI: 10.1007/s00424-010-0893-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2010] [Revised: 10/04/2010] [Accepted: 10/04/2010] [Indexed: 12/22/2022]
Abstract
Ion channels and transporters play a critical role in ion and fluid homeostasis and thus in normal animal physiology and pathology. Tight regulation of these transmembrane proteins is therefore essential. In recent years, many studies have focused their attention on the role of the ubiquitin system in regulating ion channels and transporters, initialed by the discoveries of the role of this system in processing of Cystic Fibrosis Transmembrane Regulator (CFTR), and in regulating endocytosis of the epithelial Na(+) channel (ENaC) by the Nedd4 family of ubiquitin ligases (mainly Nedd4-2). In this review, we discuss the role of the ubiquitin system in ER Associated Degradation (ERAD) of ion channels, and in the regulation of endocytosis and lysosomal sorting of ion channels and transporters, focusing primarily in mammalian cells. We also briefly discuss the role of ubiquitin like molecules (such as SUMO) in such regulation, for which much less is known so far.
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