1
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Kok M, Brodsky JL. The biogenesis of potassium transporters: implications of disease-associated mutations. Crit Rev Biochem Mol Biol 2024:1-45. [PMID: 38946646 DOI: 10.1080/10409238.2024.2369986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/16/2024] [Indexed: 07/02/2024]
Abstract
The concentration of intracellular and extracellular potassium is tightly regulated due to the action of various ion transporters, channels, and pumps, which reside primarily in the kidney. Yet, potassium transporters and cotransporters play vital roles in all organs and cell types. Perhaps not surprisingly, defects in the biogenesis, function, and/or regulation of these proteins are linked to range of catastrophic human diseases, but to date, few drugs have been approved to treat these maladies. In this review, we discuss the structure, function, and activity of a group of potassium-chloride cotransporters, the KCCs, as well as the related sodium-potassium-chloride cotransporters, the NKCCs. Diseases associated with each of the four KCCs and two NKCCs are also discussed. Particular emphasis is placed on how these complex membrane proteins fold and mature in the endoplasmic reticulum, how non-native forms of the cotransporters are destroyed in the cell, and which cellular factors oversee their maturation and transport to the cell surface. When known, we also outline how the levels and activities of each cotransporter are regulated. Open questions in the field and avenues for future investigations are further outlined.
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Affiliation(s)
- Morgan Kok
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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2
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Zhang S, Meor Azlan NF, Josiah SS, Zhou J, Zhou X, Jie L, Zhang Y, Dai C, Liang D, Li P, Li Z, Wang Z, Wang Y, Ding K, Wang Y, Zhang J. The role of SLC12A family of cation-chloride cotransporters and drug discovery methodologies. J Pharm Anal 2023; 13:1471-1495. [PMID: 38223443 PMCID: PMC10785268 DOI: 10.1016/j.jpha.2023.09.002] [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: 03/04/2023] [Revised: 06/20/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023] Open
Abstract
The solute carrier family 12 (SLC12) of cation-chloride cotransporters (CCCs) comprises potassium chloride cotransporters (KCCs, e.g. KCC1, KCC2, KCC3, and KCC4)-mediated Cl- extrusion, and sodium potassium chloride cotransporters (N[K]CCs, NKCC1, NKCC2, and NCC)-mediated Cl- loading. The CCCs play vital roles in cell volume regulation and ion homeostasis. Gain-of-function or loss-of-function of these ion transporters can cause diseases in many tissues. In recent years, there have been considerable advances in our understanding of CCCs' control mechanisms in cell volume regulations, with many techniques developed in studying the functions and activities of CCCs. Classic approaches to directly measure CCC activity involve assays that measure the transport of potassium substitutes through the CCCs. These techniques include the ammonium pulse technique, radioactive or nonradioactive rubidium ion uptake-assay, and thallium ion-uptake assay. CCCs' activity can also be indirectly observed by measuring γ-aminobutyric acid (GABA) activity with patch-clamp electrophysiology and intracellular chloride concentration with sensitive microelectrodes, radiotracer 36Cl-, and fluorescent dyes. Other techniques include directly looking at kinase regulatory sites phosphorylation, flame photometry, 22Na+ uptake assay, structural biology, molecular modeling, and high-throughput drug screening. This review summarizes the role of CCCs in genetic disorders and cell volume regulation, current methods applied in studying CCCs biology, and compounds developed that directly or indirectly target the CCCs for disease treatments.
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Affiliation(s)
- Shiyao Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Nur Farah Meor Azlan
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Sunday Solomon Josiah
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Jing Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Xiaoxia Zhou
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Lingjun Jie
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Yanhui Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Cuilian Dai
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Dong Liang
- Aurora Discovery Inc., Foshan, Guangdong, 528300, China
| | - Peifeng Li
- Institute for Translational Medicine, Qingdao University, Qingdao, Shandong, 266021, China
| | - Zhengqiu Li
- School of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Zhen Wang
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Ke Ding
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yan Wang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Jinwei Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
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3
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Zhao Y, Shen J, Wang Q, Ruiz Munevar MJ, Vidossich P, De Vivo M, Zhou M, Cao E. Structure of the human cation-chloride cotransport KCC1 in an outward-open state. Proc Natl Acad Sci U S A 2022; 119:e2109083119. [PMID: 35759661 PMCID: PMC9271165 DOI: 10.1073/pnas.2109083119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 04/25/2022] [Indexed: 12/30/2022] Open
Abstract
Cation-chloride cotransporters (CCCs) catalyze electroneutral symport of Cl- with Na+ and/or K+ across membranes. CCCs are fundamental in cell volume homeostasis, transepithelia ion movement, maintenance of intracellular Cl- concentration, and neuronal excitability. Here, we present a cryoelectron microscopy structure of human K+-Cl- cotransporter (KCC)1 bound with the VU0463271 inhibitor in an outward-open state. In contrast to many other amino acid-polyamine-organocation transporter cousins, our first outward-open CCC structure reveals that opening the KCC1 extracellular ion permeation path does not involve hinge-bending motions of the transmembrane (TM) 1 and TM6 half-helices. Instead, rocking of TM3 and TM8, together with displacements of TM4, TM9, and a conserved intracellular loop 1 helix, underlie alternate opening and closing of extracellular and cytoplasmic vestibules. We show that KCC1 intriguingly exists in one of two distinct dimeric states via different intersubunit interfaces. Our studies provide a blueprint for understanding the mechanisms of CCCs and their inhibition by small molecule compounds.
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Affiliation(s)
- Yongxiang Zhao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Jiemin Shen
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Qinzhe Wang
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | | | | | - Marco De Vivo
- Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
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4
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Hortle E, Tran VL, Wright K, Fontaine AR, Pinello N, O'Rourke MB, Wong JJL, Hansbro PM, Britton WJ, Oehlers SH. OXSR1 inhibits inflammasome activation by limiting potassium efflux during mycobacterial infection. Life Sci Alliance 2022; 5:5/9/e202201476. [PMID: 35545295 PMCID: PMC9107790 DOI: 10.26508/lsa.202201476] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 04/15/2022] [Accepted: 04/19/2022] [Indexed: 12/13/2022] Open
Abstract
Mycobacteria up-regulate host kinase OXSR1 preventing potassium efflux and inflammasome activation. Depletion or inhibition of OXSR1 potentiates inflammasome activation and decreases bacterial burden. Pathogenic mycobacteria inhibit inflammasome activation to establish infection. Although it is known that potassium efflux is a trigger for inflammasome activation, the interaction between mycobacterial infection, potassium efflux, and inflammasome activation has not been investigated. Here, we use Mycobacterium marinum infection of zebrafish embryos and Mycobacterium tuberculosis infection of THP-1 cells to demonstrate that pathogenic mycobacteria up-regulate the host WNK signalling pathway kinases SPAK and OXSR1 which control intracellular potassium balance. We show that genetic depletion or inhibition of OXSR1 decreases bacterial burden and intracellular potassium levels. The protective effects of OXSR1 depletion are at least partially mediated by NLRP3 inflammasome activation, caspase-mediated release of IL-1β, and downstream activation of protective TNF-α. The elucidation of this druggable pathway to potentiate inflammasome activation provides a new avenue for the development of host-directed therapies against intracellular infections.
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Affiliation(s)
- Elinor Hortle
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, Australia .,The University of Sydney, Discipline of Infectious Diseases and Immunology and Sydney Institute for Infectious Diseases, Camperdown, Australia.,Centre for Inflammation and University of Technology Sydney, Faculty of Science, School of Life Sciences, Sydney, Australia
| | - Vi Lt Tran
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, Australia
| | - Kathryn Wright
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, Australia
| | - Angela Rm Fontaine
- Centenary Imaging and Sydney Cytometry at the Centenary Institute, The University of Sydney, Camperdown, Australia
| | - Natalia Pinello
- Epigenetics and RNA Biology Program Centenary Institute, The University of Sydney, Camperdown, Australia.,The University of Sydney, Faculty of Medicine and Health, Camperdown, Australia
| | - Matthew B O'Rourke
- Centre for Inflammation and University of Technology Sydney, Faculty of Science, School of Life Sciences, Sydney, Australia
| | - Justin J-L Wong
- Epigenetics and RNA Biology Program Centenary Institute, The University of Sydney, Camperdown, Australia.,The University of Sydney, Faculty of Medicine and Health, Camperdown, Australia
| | - Philip M Hansbro
- Centre for Inflammation and University of Technology Sydney, Faculty of Science, School of Life Sciences, Sydney, Australia
| | - Warwick J Britton
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, Australia.,Department of Clinical Immunology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - Stefan H Oehlers
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, Australia .,The University of Sydney, Discipline of Infectious Diseases and Immunology and Sydney Institute for Infectious Diseases, Camperdown, Australia.,A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
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5
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Sánchez-Arcila JC, Jensen KDC. Forward Genetics in Apicomplexa Biology: The Host Side of the Story. Front Cell Infect Microbiol 2022; 12:878475. [PMID: 35646724 PMCID: PMC9133346 DOI: 10.3389/fcimb.2022.878475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
Forward genetic approaches have been widely used in parasitology and have proven their power to reveal the complexities of host-parasite interactions in an unbiased fashion. Many aspects of the parasite's biology, including the identification of virulence factors, replication determinants, antibiotic resistance genes, and other factors required for parasitic life, have been discovered using such strategies. Forward genetic approaches have also been employed to understand host resistance mechanisms to parasitic infection. Here, we will introduce and review all forward genetic approaches that have been used to identify host factors involved with Apicomplexa infections, which include classical genetic screens and QTL mapping, GWAS, ENU mutagenesis, overexpression, RNAi and CRISPR-Cas9 library screens. Collectively, these screens have improved our understanding of host resistance mechanisms, immune regulation, vaccine and drug designs for Apicomplexa parasites. We will also discuss how recent advances in molecular genetics give present opportunities to further explore host-parasite relationships.
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Affiliation(s)
- Juan C. Sánchez-Arcila
- Department of Molecular and Cell Biology, University of California Merced, Merced, CA, United States
| | - Kirk D. C. Jensen
- Department of Molecular and Cell Biology, University of California Merced, Merced, CA, United States
- Health Science Research Institute, University of California, Merced, Merced, CA, United States
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6
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Chi G, Ebenhoch R, Man H, Tang H, Tremblay LE, Reggiano G, Qiu X, Bohstedt T, Liko I, Almeida FG, Garneau AP, Wang D, McKinley G, Moreau CP, Bountra KD, Abrusci P, Mukhopadhyay SMM, Fernandez‐Cid A, Slimani S, Lavoie JL, Burgess‐Brown NA, Tehan B, DiMaio F, Jazayeri A, Isenring P, Robinson CV, Dürr KL. Phospho-regulation, nucleotide binding and ion access control in potassium-chloride cotransporters. EMBO J 2021; 40:e107294. [PMID: 34031912 PMCID: PMC8280820 DOI: 10.15252/embj.2020107294] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/29/2021] [Accepted: 04/11/2021] [Indexed: 11/26/2022] Open
Abstract
Potassium-coupled chloride transporters (KCCs) play crucial roles in regulating cell volume and intracellular chloride concentration. They are characteristically inhibited under isotonic conditions via phospho-regulatory sites located within the cytoplasmic termini. Decreased inhibitory phosphorylation in response to hypotonic cell swelling stimulates transport activity, and dysfunction of this regulatory process has been associated with various human diseases. Here, we present cryo-EM structures of human KCC3b and KCC1, revealing structural determinants for phospho-regulation in both N- and C-termini. We show that phospho-mimetic KCC3b is arrested in an inward-facing state in which intracellular ion access is blocked by extensive contacts with the N-terminus. In another mutant with increased isotonic transport activity, KCC1Δ19, this interdomain interaction is absent, likely due to a unique phospho-regulatory site in the KCC1 N-terminus. Furthermore, we map additional phosphorylation sites as well as a previously unknown ATP/ADP-binding pocket in the large C-terminal domain and show enhanced thermal stabilization of other CCCs by adenine nucleotides. These findings provide fundamentally new insights into the complex regulation of KCCs and may unlock innovative strategies for drug development.
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Affiliation(s)
- Gamma Chi
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Rebecca Ebenhoch
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- Present address:
MedChem, Boehringer Ingelheim Pharma GmbH & Co. KGBiberachGermany
| | - Henry Man
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- Present address:
Exscientia LtdOxfordUK
| | - Haiping Tang
- Physical and Theoretical Chemistry LaboratoryUniversity of OxfordOxfordUK
| | - Laurence E Tremblay
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
| | | | - Xingyu Qiu
- Physical and Theoretical Chemistry LaboratoryUniversity of OxfordOxfordUK
| | - Tina Bohstedt
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | | | | | - Alexandre P Garneau
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
- Cardiometabolic Axis, School of Kinesiology and Physical Activity SciencesUniversity of MontréalMontréalQCCanada
| | - Dong Wang
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Gavin McKinley
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Christophe P Moreau
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Present address:
Celonic AGBaselGermany
| | | | - Patrizia Abrusci
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- Present address:
Exscientia LtdOxfordUK
| | - Shubhashish M M Mukhopadhyay
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Alejandra Fernandez‐Cid
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Samira Slimani
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
| | - Julie L Lavoie
- Cardiometabolic Axis, School of Kinesiology and Physical Activity SciencesUniversity of MontréalMontréalQCCanada
| | - Nicola A Burgess‐Brown
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | | | - Frank DiMaio
- Department of BiochemistryUniversity of WashingtonSeattleWAUSA
| | | | - Paul Isenring
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
| | - Carol V Robinson
- Physical and Theoretical Chemistry LaboratoryUniversity of OxfordOxfordUK
| | - Katharina L Dürr
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- OMass Therapeutics, Ltd.OxfordUK
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7
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Garneau AP, Slimani S, Tremblay LE, Fiola MJ, Marcoux AA, Isenring P. K +-Cl - cotransporter 1 (KCC1): a housekeeping membrane protein that plays key supplemental roles in hematopoietic and cancer cells. J Hematol Oncol 2019; 12:74. [PMID: 31296230 PMCID: PMC6624878 DOI: 10.1186/s13045-019-0766-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 06/30/2019] [Indexed: 01/04/2023] Open
Abstract
During the 1970s, a Na+-independent, ouabain-insensitive, N-ethylmaleimide-stimulated K+-Cl- cotransport mechanism was identified in red blood cells for the first time and in a variety of cell types afterward. During and just after the mid-1990s, three closely related isoforms were shown to account for this mechanism. They were termed K+-Cl- cotransporter 1 (KCC1), KCC3, and KCC4 according to the nomenclature of Gillen et al. (1996) who had been the first research group to uncover the molecular identity of a KCC, that is, of KCC1 in rabbit kidney. Since then, KCC1 has been found to be the most widely distributed KCC isoform and considered to act as a housekeeping membrane protein. It has perhaps received less attention than the other isoforms for this reason, but as will be discussed in the following review, there is probably more to KCC1 than meets the eye. In particular, the so-called housekeeping gene also appears to play crucial and specific roles in normal as well as pathological hematopoietic and in cancer cells.
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Affiliation(s)
- A P Garneau
- From the Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), G1R 2J6, Canada
- Cardiometabolic Axis, School of Kinesiology and Physical Activity Sciences, University of Montréal, 900, rue Saint-Denis, Montréal (Qc), H2X 0A9, Canada
| | - S Slimani
- From the Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), G1R 2J6, Canada
| | - L E Tremblay
- From the Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), G1R 2J6, Canada
| | - M J Fiola
- From the Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), G1R 2J6, Canada
| | - A A Marcoux
- From the Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), G1R 2J6, Canada
| | - P Isenring
- From the Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), G1R 2J6, Canada.
- L'Hôtel-Dieu de Québec Institution, 10, rue McMahon, Québec (Qc), G1R 2J6, Canada.
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8
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Hortle E, Starrs L, Brown FC, Jane SM, Curtis DJ, McMorran BJ, Foote SJ, Burgio G. KCC1 Activation protects Mice from the Development of Experimental Cerebral Malaria. Sci Rep 2019; 9:6356. [PMID: 31015511 PMCID: PMC6478876 DOI: 10.1038/s41598-019-42782-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 04/08/2019] [Indexed: 11/15/2022] Open
Abstract
Plasmodium falciparum malaria causes half a million deaths per year, with up to 9% of this mortality caused by cerebral malaria (CM). One of the major processes contributing to the development of CM is an excess of host inflammatory cytokines. Recently K+ signaling has emerged as an important mediator of the inflammatory response to infection; we therefore investigated whether mice carrying an ENU induced activation of the electroneutral K+ channel KCC1 had an altered response to Plasmodium berghei. Here we show that Kcc1M935K/M935K mice are protected from the development of experimental cerebral malaria, and that this protection is associated with an increased CD4+ and TNFa response. This is the first description of a K+ channel affecting the development of experimental cerebral malaria.
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Affiliation(s)
- Elinor Hortle
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australian National University, Australian Capital Territory, Australia
| | - Lora Starrs
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australian National University, Australian Capital Territory, Australia
| | - Fiona C Brown
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Australia
| | - Stephen M Jane
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Australia.,The Alfred Hospital, Melbourne, Australia.,Department of Medicine, Central Clinical School, Monash University, Melbourne, Australia
| | - David J Curtis
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Australia.,The Alfred Hospital, Melbourne, Australia
| | - Brendan J McMorran
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australian National University, Australian Capital Territory, Australia
| | - Simon J Foote
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australian National University, Australian Capital Territory, Australia
| | - Gaetan Burgio
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australian National University, Australian Capital Territory, Australia.
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9
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Abstract
Cell dehydration is a distinguishing characteristic of sickle cell disease and an important contributor to disease pathophysiology. Due to the unique dependence of Hb S polymerization on cellular Hb S concentration, cell dehydration promotes polymerization and sickling. In double heterozygosis for Hb S and C (SC disease) dehydration is the determining factor in disease pathophysiology. Three major ion transport pathways are involved in sickle cell dehydration: the K-Cl cotransport (KCC), the Gardos channel (KCNN4) and Psickle, the polymerization induced membrane permeability, most likely mediated by the mechano-sensitive ion channel PIEZO1. Each of these pathways exhibit unique characteristics in regulation by oxygen tension, intracellular and extracellular environment, and functional expression in reticulocytes and mature red cells. The unique dependence of K-Cl cotransport on intracellular Mg and the abnormal reduction of erythrocyte Mg content in SS and SC cells had led to clinical studies assessing the effect of oral Mg supplementation. Inhibition of Gardos channel by clotrimazole and senicapoc has led to Phase 1,2,3 trials in patients with sickle cell disease. While none of these studies has resulted in the approval of a novel therapy for SS disease, they have highlighted the key role played by these pathways in disease pathophysiology.
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Affiliation(s)
- Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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10
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Conway LC, Cardarelli RA, Moore YE, Jones K, McWilliams LJ, Baker DJ, Burnham MP, Bürli RW, Wang Q, Brandon NJ, Moss SJ, Deeb TZ. N-Ethylmaleimide increases KCC2 cotransporter activity by modulating transporter phosphorylation. J Biol Chem 2017; 292:21253-21263. [PMID: 29092909 PMCID: PMC5766942 DOI: 10.1074/jbc.m117.817841] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 10/27/2017] [Indexed: 11/06/2022] Open
Abstract
K+/Cl- cotransporter 2 (KCC2) is selectively expressed in the adult nervous system and allows neurons to maintain low intracellular Cl- levels. Thus, KCC2 activity is an essential prerequisite for fast hyperpolarizing synaptic inhibition mediated by type A γ-aminobutyric acid (GABAA) receptors, which are Cl--permeable, ligand-gated ion channels. Consistent with this, deficits in the activity of KCC2 lead to epilepsy and are also implicated in neurodevelopmental disorders, neuropathic pain, and schizophrenia. Accordingly, there is significant interest in developing activators of KCC2 as therapeutic agents. To provide insights into the cellular processes that determine KCC2 activity, we have investigated the mechanism by which N-ethylmaleimide (NEM) enhances transporter activity using a combination of biochemical and electrophysiological approaches. Our results revealed that, within 15 min, NEM increased cell surface levels of KCC2 and modulated the phosphorylation of key regulatory residues within the large cytoplasmic domain of KCC2 in neurons. More specifically, NEM increased the phosphorylation of serine 940 (Ser-940), whereas it decreased phosphorylation of threonine 1007 (Thr-1007). NEM also reduced with no lysine (WNK) kinase phosphorylation of Ste20-related proline/alanine-rich kinase (SPAK), a kinase that directly phosphorylates KCC2 at residue Thr-1007. Mutational analysis revealed that Thr-1007 dephosphorylation mediated the effects of NEM on KCC2 activity. Collectively, our results suggest that compounds that either increase the surface stability of KCC2 or reduce Thr-1007 phosphorylation may be of use as enhancers of KCC2 activity.
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Affiliation(s)
- Leslie C Conway
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, Massachusetts 02111
| | - Ross A Cardarelli
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, Massachusetts 02111
| | - Yvonne E Moore
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Karen Jones
- Discovery Sciences, IMED Biotech Unit, AstraZeneca, Alderley Park SK10 4TG, United Kingdom
| | - Lisa J McWilliams
- Discovery Sciences, IMED Biotech Unit, AstraZeneca, Cambridge CB4 0WG, United Kingdom
| | - David J Baker
- Discovery Sciences, IMED Biotech Unit, AstraZeneca, Cambridge CB4 0WG, United Kingdom
| | - Matthew P Burnham
- Discovery Sciences, IMED Biotech Unit, AstraZeneca, Alderley Park SK10 4TG, United Kingdom
| | - Roland W Bürli
- Neuroscience, IMED Biotech Unit, AstraZeneca, Cambridge CB21 6GH, United Kingdom, and
| | - Qi Wang
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, Massachusetts 02111
- Neuroscience, IMED Biotech Unit, AstraZeneca, Boston, Massachusetts 02451
| | - Nicholas J Brandon
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, Massachusetts 02111
- Neuroscience, IMED Biotech Unit, AstraZeneca, Boston, Massachusetts 02451
| | - Stephen J Moss
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, Massachusetts 02111,
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Tarek Z Deeb
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, Massachusetts 02111
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
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11
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Mittelman M, Platzbecker U, Afanasyev B, Grosicki S, Wong RSM, Anagnostopoulos A, Brenner B, Denzlinger C, Rossi G, Nagler A, Garcia-Delgado R, Portella MSO, Zhu Z, Selleslag D. Eltrombopag for advanced myelodysplastic syndromes or acute myeloid leukaemia and severe thrombocytopenia (ASPIRE): a randomised, placebo-controlled, phase 2 trial. LANCET HAEMATOLOGY 2017; 5:e34-e43. [PMID: 29241762 DOI: 10.1016/s2352-3026(17)30228-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/09/2017] [Accepted: 11/10/2017] [Indexed: 12/26/2022]
Abstract
BACKGROUND Thrombocytopenia is a life-threatening complication in patients with advanced myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML). In this study (ASPIRE), we aimed to assess eltrombopag, an oral thrombopoietin receptor agonist, for thrombocytopenia (grade 4) treatment in adult patients with advanced MDS or AML. METHODS ASPIRE consisted of an open-label, double-blind phase for 8 weeks and a randomised, double-blind phase (parts 1 and 2, reported here) for 12 weeks, and an open-label extension (part 3). Eligible patients were men and women aged 18 years or older, with intermediate-2 or high-risk MDS or AML, with bone marrow blasts of 50% or less, and had either grade 4 thrombocytopenia due to bone marrow insufficiency (platelet counts <25 × 109 per L) or grade 4 thrombocytopenia before platelet transfusion, with 25 × 109 platelets per L or greater after transfusion. Additionally, eligible patients had at least one of the following within the screening period of 4 weeks: platelet transfusion, symptomatic bleeding, or platelet count of less than 10 × 109 per L. During part 1, patients received eltrombopag, and dose-escalation criteria for part 2 were determined. In part 2, we randomly allocated patients 2:1 using an interactive voice-response system to eltrombopag or placebo, stratified by baseline platelet count (<10 × 109 platelets per L vs ≥10 × 109 platelets per L) and disease (MDS vs AML). In parts 1 and 2, patients received supportive standard of care and initiated eltrombopag or placebo at 100 mg per day (50 mg per day for patients of east-Asian heritage) to a maximum of 300 mg per day (150 mg per day for patients of east-Asian heritage). The part 2 primary objective was assessed by a composite primary endpoint of clinically relevant thrombocytopenic events (CRTE) during weeks 5-12, defined as one of the following events, either alone or in combination: grade 3 or worse haemorrhagic adverse events; platelet counts of less than 10 × 109 per L; or platelet transfusions. Efficacy analyses were based on intention to treat; clinically meaningful efficacy was defined as 30% absolute difference between groups. This trial is registered with ClinicalTrials.gov, number NCT01440374. FINDINGS In part 1, 17 patients received eltrombopag and 11 patients completed treatment; four experienced significantly increased platelet counts, and ten had reduced platelet transfusion requirements. In part 2 we randomly allocated 145 patients to receive supportive care plus eltrombopag (n=98) or placebo (n=47); similar proportions had MDS (50 [51%] patients to eltrombopag, 22 (47%) patients to placebo) or AML (48 [49%] patients to eltrombopag, 25 [53%] patients to placebo). Average weekly CRTE proportions from weeks 5-12 were significantly lower with eltrombopag (54% [95% CI 43-64]) than with placebo (69% [57-80], odds ratio [OR] 0·20, 95% CI 0·05-0·87; p=0·032) although the difference between treatment groups was less than 30%. The most common grade 3 and grade 4 adverse events were fatigue (six [6%] in the eltrombopag group and one [2%] in the placebo group), hypokalaemia (six [6%] and two [4%]), pneumonia (five [5%] and five [11%]), and febrile neutropenia (five [5%] and six [13%]). Serious adverse events were reported in 56 (58%) eltrombopag-treated patients and 32 (68%) placebo-treated patients. Seven eltrombopag recipients and two placebo recipients had serious adverse events that were suspected to be study drug-related (eltrombopag: acute kidney injury, arterial thrombosis, bone pain, diarrhoea, myocardial infarction, pyrexia, retinal vein occlusion, n=1 each; placebo: vomiting, white blood cell count increased, n=1 each). Two eltrombopag recipients (arterial thrombosis n=1; myocardial infarction n=1) and no placebo recipients experienced fatal serious adverse events suspected to be study drug-related. INTERPRETATION No new safety concerns were noted with eltrombopag and the trial met the primary objective of a reduction in CRTEs; eltrombopag might be a treatment option for thrombocytopenic patients with AML or MDS who are ineligible for other treatment and who are not receiving disease-modifying treatment. FUNDING Novartis Pharma AG.
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Affiliation(s)
- Moshe Mittelman
- Tel Aviv Sourasky Medical Center, Sackler Medical Faculty, Tel Aviv University, Tel Aviv, Israel.
| | | | | | | | - Raymond S M Wong
- Sir YK Pao Centre for Cancer & Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China
| | | | - Benjamin Brenner
- Rambam Medical Center, Technion, Israel Institute of Technology, Haifa, Israel
| | | | | | - Arnon Nagler
- Sheba Medical Center, Tel Hashomer, Tel Aviv University, Tel Aviv, Israel
| | | | | | - Zewen Zhu
- Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA
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12
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Molecular features and physiological roles of K +-Cl - cotransporter 4 (KCC4). Biochim Biophys Acta Gen Subj 2017; 1861:3154-3166. [PMID: 28935604 DOI: 10.1016/j.bbagen.2017.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/15/2017] [Indexed: 12/27/2022]
Abstract
A K+-Cl- cotransport system was documented for the first time during the mid-seventies in sheep and goat red blood cells. It was then described as a Na+-independent and ouabain-insensitive ion carrier that could be stimulated by cell swelling and N-ethylmaleimide (NEM), a thiol-reacting agent. Twenty years later, this system was found to be dispensed by four different isoforms in animal cells. The first one was identified in the expressed sequence tag (EST) database by Gillen et al. based on the assumption that it would be homologous to the Na+-dependent K+-Cl- cotransport system for which the molecular identity had already been uncovered. Not long after, the three other isoforms were once again identified in the EST databank. Among those, KCC4 has generated much interest a few years ago when it was shown to sustain distal renal acidification and hearing development in mouse. As will be seen in this review, many additional roles were ascribed to this isoform, in keeping with its wide distribution in animal species. However, some of them have still not been confirmed through animal models of gene inactivation or overexpression. Along the same line, considerable knowledge has been acquired on the mechanisms by which KCC4 is regulated and the environmental cues to which it is sensitive. Yet, it is inferred to some extent from historical views and extrapolations.
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13
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Yang E, Voelkel EB, Lezon-Geyda K, Schulz VP, Gallagher PG. Hemoglobin C trait accentuates erythrocyte dehydration in hereditary xerocytosis. Pediatr Blood Cancer 2017; 64:10.1002/pbc.26444. [PMID: 28121068 PMCID: PMC5858911 DOI: 10.1002/pbc.26444] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 12/13/2016] [Accepted: 12/13/2016] [Indexed: 02/06/2023]
Abstract
A 17-year-old male presented with acute hemolysis with stomatocytosis, elevated mean corpuscular hemoglobin concentration (MCHC), and osmotic gradient ektacytometry consistent with marked erythrocyte dehydration. Erythrocytes from both parents also demonstrated evidence of dehydration with elevated MCHC and abnormal ektacytometry, but neither to the degree of the patient. Genetic studies revealed the patient had hereditary xerocytosis (HX) due to a novel PIEZO1 mutation inherited from his mother and hemoglobin C (HbC) trait inherited from his father. HbC trait accentuated the erythrocyte dehydration of HX. Coinheritance of interrelated disorders and/or modifier alleles should be considered whenever severe erythrocyte dehydration is observed.
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Affiliation(s)
- Elizabeth Yang
- Department of Pediatrics, George Washington University School of Medicine, Washington, District of Columbia
| | - Erin B. Voelkel
- Department of Pediatrics, Inova Fairfax Hospital, Falls Church, Virginia
| | - Kimberly Lezon-Geyda
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | - Vincent P. Schulz
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | - Patrick G. Gallagher
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut,Departments of Pathology and Genetics, University School of Medicine, New Haven, Connecticut
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Brown FC, Collett M, Tremblay CS, Rank G, De Camilli P, Booth CJ, Bitoun M, Robinson PJ, Kile BT, Jane SM, Curtis DJ. Loss of Dynamin 2 GTPase function results in microcytic anaemia. Br J Haematol 2017; 178:616-628. [PMID: 28466468 DOI: 10.1111/bjh.14709] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/27/2017] [Indexed: 12/24/2022]
Abstract
In a dominant mouse ethylnitrosurea mutagenesis screen for genes regulating erythropoiesis, we identified a pedigree with a novel microcytic hypochromia caused by a V235G missense mutation in Dynamin 2 (Dnm2). Mutations in Dnm2, a GTPase, are highly disease-specific and have been implicated in four forms of human diseases: centronuclear myopathy, Charcot-Marie Tooth neuropathy and, more recently, T-cell leukaemia and Hereditary Spastic Paraplegia, but red cell abnormalities have not been reported to date. The V235G mutation lies within a crucial GTP nucleotide-binding pocket of Dnm2, and resulted in defective GTPase activity and incompatibility with life in the homozygous state. Dnm2 is an essential mediator of clathrin-mediated endocytosis, which is required for the uptake of transferrin (Tf) into red cells for incorporation of haem. Accordingly, we observed significantly reduced Tf uptake by Dnm2+/V235G cells, which led to impaired endosome formation. Despite these deficiencies, surprisingly all iron studies were unchanged, suggesting an unexplained alternative mechanism underlies microcytic anaemia in Dnm2+/V235G mice. This study provides the first in vivo evidence for the requirements of Dnm2 in normal erythropoiesis.
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Affiliation(s)
- Fiona C Brown
- Australian Centre for Blood Diseases, Central Clinical School, Monash University and Alfred Health, Melbourne, Vic., Australia
| | - Michael Collett
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Cedric S Tremblay
- Australian Centre for Blood Diseases, Central Clinical School, Monash University and Alfred Health, Melbourne, Vic., Australia
| | - Gerhard Rank
- Rotary Bone Marrow Research Laboratory, Royal Melbourne Hospital, Melbourne, Vic., Australia
| | - Pietro De Camilli
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Carmen J Booth
- Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Marc Bitoun
- Research Centre for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, CNRS FRE 3617, Institute of Myology, Paris, France
| | - Phillip J Robinson
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Benjamin T Kile
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Vic., Australia
| | - Stephen M Jane
- Australian Centre for Blood Diseases, Central Clinical School, Monash University and Alfred Health, Melbourne, Vic., Australia
| | - David J Curtis
- Australian Centre for Blood Diseases, Central Clinical School, Monash University and Alfred Health, Melbourne, Vic., Australia
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Abstract
PURPOSE OF REVIEW Sickle cell disease (SCD) afflicts millions worldwide. The simplicity of its single nucleotide mutation belies the biological and psychosocial complexity of the disease. Despite only a single approved drug specifically for the treatment of SCD, new findings reviewed from 2015 provide the direction forward. RECENT FINDINGS The last year has provided a wealth of support for mechanisms affecting the red cell, hemolysis and vasculopathy, the innate immune system activation, blood cell and endothelial adhesiveness, central sensitization to pain, and chronic brain injury. The evidence supporting expanded use of hydroxyurea continues to mount. Many promising therapies are reaching clinical trial, including curative therapies, with more on the horizon. SUMMARY Evidence is compelling that the use of hydroxyurea must be expanded by clinicians to gain the full pleiotropic benefits of this approved drug. Clinicians must become aware that severe acute and chronic pain has a biological and neurologic basis, and the understanding of this basis is growing. Researchers are testing investigational therapies at an unprecedented pace in SCD, and partnership between patients, researchers, and the private sector provides the most rapid and productive way forward.
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Jentsch TJ. VRACs and other ion channels and transporters in the regulation of cell volume and beyond. Nat Rev Mol Cell Biol 2016; 17:293-307. [PMID: 27033257 DOI: 10.1038/nrm.2016.29] [Citation(s) in RCA: 217] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cells need to regulate their volume to counteract osmotic swelling or shrinkage, as well as during cell division, growth, migration and cell death. Mammalian cells adjust their volume by transporting potassium, sodium, chloride and small organic osmolytes using plasma membrane channels and transporters. This generates osmotic gradients, which drive water in and out of cells. Key players in this process are volume-regulated anion channels (VRACs), the composition of which has recently been identified and shown to encompass LRRC8 heteromers. VRACs also transport metabolites and drugs and function in extracellular signal transduction, apoptosis and anticancer drug resistance.
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Affiliation(s)
- Thomas J Jentsch
- Leibniz-Institut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany
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