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Górska AM, Santos-García I, Eiriz I, Brüning T, Nyman T, Pahnke J. Evaluation of cerebrospinal fluid (CSF) and interstitial fluid (ISF) mouse proteomes for the validation and description of Alzheimer's disease biomarkers. J Neurosci Methods 2024; 411:110239. [PMID: 39102902 DOI: 10.1016/j.jneumeth.2024.110239] [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: 03/26/2024] [Revised: 07/22/2024] [Accepted: 07/26/2024] [Indexed: 08/07/2024]
Abstract
BACKGROUND Mass spectrometry (MS)-based cerebrospinal fluid (CSF) proteomics is an important method for discovering biomarkers of neurodegenerative diseases. CSF serves as a reservoir for interstitial fluid (ISF), and extensive communication between the two fluid compartments helps to remove waste products from the brain. NEW METHOD We performed proteomic analyses of both CSF and ISF fluid compartments using intracerebral microdialysis to validate and detect novel biomarkers of Alzheimer's disease (AD) in APPtg and C57Bl/6J control mice. RESULTS We identified up to 625 proteins in ISF and 4483 proteins in CSF samples. By comparing the biofluid profiles of APPtg and C57Bl/6J mice, we detected 37 and 108 significantly up- and downregulated candidates, respectively. In ISF, 7 highly regulated proteins, such as Gfap, Aldh1l1, Gstm1, and Txn, have already been implicated in AD progression, whereas in CSF, 9 out of 14 highly regulated proteins, such as Apba2, Syt12, Pgs1 and Vsnl1, have also been validated to be involved in AD pathogenesis. In addition, we also detected new interesting regulated proteins related to the control of synapses and neurotransmission (Kcna2, Cacng3, and Clcn6) whose roles as AD biomarkers should be further investigated. COMPARISON WITH EXISTING METHODS This newly established combined protocol provides better insight into the mutual communication between ISF and CSF as an analysis of tissue or CSF compartments alone. CONCLUSIONS The use of multiple fluid compartments, ISF and CSF, for the detection of their biological communication enables better detection of new promising AD biomarkers.
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Affiliation(s)
- Anna Maria Górska
- Translational Neurodegeneration Research and Neuropathology Lab, Department of Clinical Medicine (KlinMed), Medical Faculty, University of Oslo (UiO) and Section of Neuropathology Research, Department of Pathology, Clinics for Laboratory Medicine (KLM), Oslo University Hospital (OUS), Sognsvannsveien 20, Oslo NO-0372, Norway.
| | - Irene Santos-García
- Translational Neurodegeneration Research and Neuropathology Lab, Department of Clinical Medicine (KlinMed), Medical Faculty, University of Oslo (UiO) and Section of Neuropathology Research, Department of Pathology, Clinics for Laboratory Medicine (KLM), Oslo University Hospital (OUS), Sognsvannsveien 20, Oslo NO-0372, Norway.
| | - Ivan Eiriz
- Translational Neurodegeneration Research and Neuropathology Lab, Department of Clinical Medicine (KlinMed), Medical Faculty, University of Oslo (UiO) and Section of Neuropathology Research, Department of Pathology, Clinics for Laboratory Medicine (KLM), Oslo University Hospital (OUS), Sognsvannsveien 20, Oslo NO-0372, Norway.
| | - Thomas Brüning
- Translational Neurodegeneration Research and Neuropathology Lab, Department of Clinical Medicine (KlinMed), Medical Faculty, University of Oslo (UiO) and Section of Neuropathology Research, Department of Pathology, Clinics for Laboratory Medicine (KLM), Oslo University Hospital (OUS), Sognsvannsveien 20, Oslo NO-0372, Norway.
| | - Tuula Nyman
- Proteomics Core Facility, Department of Immunology, Oslo University Hospital (OUS) and University of Oslo (UiO), Faculty of Medicine, Sognsvannsveien 20, Oslo NO-0372, Norway.
| | - Jens Pahnke
- Translational Neurodegeneration Research and Neuropathology Lab, Department of Clinical Medicine (KlinMed), Medical Faculty, University of Oslo (UiO) and Section of Neuropathology Research, Department of Pathology, Clinics for Laboratory Medicine (KLM), Oslo University Hospital (OUS), Sognsvannsveien 20, Oslo NO-0372, Norway; Institute of Nutritional Medicine (INUM) and Lübeck Institute of Dermatology (LIED), University of Lübeck (UzL) and University Medical Center Schleswig-Holstein (UKSH), Ratzeburger Allee 160, Lübeck D-23538, Germany; Department of Pharmacology, Faculty of Medicine and Life Sciences, University of Latvia, Jelgavas iela 3, Rīga LV-1004, Latvia; School of Neurobiology, Biochemistry and Biophysics, The Georg S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv IL-6997801, Israel.
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He H, Cao X, He F, Zhang W, Wang X, Peng P, Xie C, Yin F, Li D, Li J, Wang M, Klüssendorf M, Jentsch TJ, Stauber T, Peng J. Mutations in CLCN6 as a Novel Genetic Cause of Neuronal Ceroid Lipofuscinosis in Patients and a Murine Model. Ann Neurol 2024; 96:608-624. [PMID: 38877824 DOI: 10.1002/ana.27002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 04/30/2024] [Accepted: 05/08/2024] [Indexed: 06/16/2024]
Abstract
OBJECTIVE The aim of this study was to explore the pathogenesis of CLCN6-related disease and to assess whether its Cl-/H+-exchange activity is crucial for the biological role of ClC-6. METHODS We performed whole-exome sequencing on a girl with development delay, intractable epilepsy, behavioral abnormities, retinal dysfunction, progressive brain atrophy, suggestive of neuronal ceroid lipofuscinoses (NCLs). We generated and analyzed the first knock-in mouse model of a patient variant (p.E200A) and compared it with a Clcn6-/- mouse model. Additional functional tests were performed with heterologous expression of mutant ClC-6. RESULTS We identified a de novo heterozygous p.E200A variant in the proband. Expression of disease-causing ClC-6E200A or ClC-6Y553C mutants blocked autophagic flux and activated transcription factors EB (TFEB) and E3 (TFE3), leading to autophagic vesicle and cholesterol accumulation. Such alterations were absent with a transport-deficient ClC-6E267A mutant. Clcn6E200A/+ mice developed severe neurodegeneration with typical features of NCLs. Mutant ClC-6E200A, but not loss of ClC-6 in Clcn6-/- mice, increased lysosomal biogenesis by suppressing mTORC1-TFEB signaling, blocked autophagic flux through impairing lysosomal function, and increased apoptosis. Carbohydrate and lipid deposits accumulated in Clcn6E200A/+ brain, while only lipid storage was found in Clcn6-/- brain. Lysosome dysfunction, autophagy defects, and gliosis were early pathogenic events preceding neuron loss. INTERPRETATION CLCN6 is a novel genetic cause of NCLs, highlighting the importance of considering CLCN6 mutations in the diagnostic workup for molecularly undefined forms of NCLs. Uncoupling of Cl- transport from H+ countertransport in the E200A mutant has a dominant effect on the autophagic/lysosomal pathway. ANN NEUROL 2024;96:608-624.
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Affiliation(s)
- Hailan He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Changsha, China
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Xiaoshuang Cao
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Changsha, China
| | - Wen Zhang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Changsha, China
| | - Xiaole Wang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Changsha, China
| | - Pan Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Changsha, China
| | - Changning Xie
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Changsha, China
| | - Dengfeng Li
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, China
| | - Jiada Li
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, China
| | - Minghui Wang
- The First People's Hospital of Changde, Changde, China
| | - Malte Klüssendorf
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Thomas J Jentsch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Tobias Stauber
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Changsha, China
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Festa M, Coppola MA, Angeli E, Tettey-Matey A, Giusto A, Mazza I, Gatta E, Barbieri R, Picollo A, Gavazzo P, Pusch M, Picco C, Sbrana F. TMEM9B Regulates Endosomal ClC-3 and ClC-4 Transporters. Life (Basel) 2024; 14:1034. [PMID: 39202776 PMCID: PMC11355779 DOI: 10.3390/life14081034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Revised: 08/12/2024] [Accepted: 08/15/2024] [Indexed: 09/03/2024] Open
Abstract
The nine-member CLC gene family of Cl- chloride-transporting membrane proteins is divided into plasma membrane-localized Cl- channels and endo-/lysosomal Cl-/H+ antiporters. Accessory proteins have been identified for ClC-K and ClC-2 channels and for the lysosomal ClC-7, but not the other CLCs. Here, we identified TMEM9 Domain Family Member B (TMEM9B), a single-span type I transmembrane protein of unknown function, to strongly interact with the neuronal endosomal ClC-3 and ClC-4 transporters. Co-expression of TMEM9B with ClC-3 or ClC-4 dramatically reduced transporter activity in Xenopus oocytes and transfected HEK cells. For ClC-3, TMEM9B also induced a slow component in the kinetics of the activation time course, suggesting direct interaction. Currents mediated by ClC-7 were hardly affected by TMEM9B, and ClC-1 currents were only slightly reduced, demonstrating specific interaction with ClC-3 and ClC-4. We obtained strong evidence for direct interaction by detecting significant Förster Resonance Energy Transfer (FRET), exploiting fluorescence lifetime microscopy-based (FLIM-FRET) techniques between TMEM9B and ClC-3 and ClC-4, but hardly any FRET with ClC-1 or ClC-7. The discovery of TMEM9B as a novel interaction partner of ClC-3 and ClC-4 might have important implications for the physiological role of these transporters in neuronal endosomal homeostasis and for a better understanding of the pathological mechanisms in CLCN3- and CLCN4-related pathological conditions.
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Affiliation(s)
- Margherita Festa
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Maria Antonietta Coppola
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Elena Angeli
- DIFI Lab, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy; (E.A.); (E.G.)
| | - Abraham Tettey-Matey
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Alice Giusto
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Irene Mazza
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Elena Gatta
- DIFI Lab, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy; (E.A.); (E.G.)
| | - Raffaella Barbieri
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Alessandra Picollo
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Paola Gavazzo
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Michael Pusch
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Cristiana Picco
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
| | - Francesca Sbrana
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy; (M.F.); (M.A.C.); (A.T.-M.); (A.G.); (I.M.); (R.B.); (A.P.); (P.G.)
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Wan Y, Guo S, Zhen W, Xu L, Chen X, Liu F, Shen Y, Liu S, Hu L, Wang X, Ye F, Wang Q, Wen H, Yang F. Structural basis of adenine nucleotides regulation and neurodegenerative pathology in ClC-3 exchanger. Nat Commun 2024; 15:6654. [PMID: 39107281 PMCID: PMC11303396 DOI: 10.1038/s41467-024-50975-w] [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: 10/16/2023] [Accepted: 07/25/2024] [Indexed: 08/10/2024] Open
Abstract
The ClC-3 chloride/proton exchanger is both physiologically and pathologically critical, as it is potentiated by ATP to detect metabolic energy level and point mutations in ClC-3 lead to severe neurodegenerative diseases in human. However, why this exchanger is differentially modulated by ATP, ADP or AMP and how mutations caused gain-of-function remains largely unknow. Here we determine the high-resolution structures of dimeric wildtype ClC-3 in the apo state and in complex with ATP, ADP and AMP, and the disease-causing I607T mutant in the apo and ATP-bounded state by cryo-electron microscopy. In combination with patch-clamp recordings and molecular dynamic simulations, we reveal how the adenine nucleotides binds to ClC-3 and changes in ion occupancy between apo and ATP-bounded state. We further observe I607T mutation induced conformational changes and augments in current. Therefore, our study not only lays the structural basis of adenine nucleotides regulation in ClC-3, but also clearly indicates the target region for drug discovery against ClC-3 mediated neurodegenerative diseases.
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Affiliation(s)
- Yangzhuoqun Wan
- Department of Biophysics and Disease Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China
| | - Shuangshuang Guo
- Department of Biophysics and Disease Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China
| | - Wenxuan Zhen
- Department of Biophysics and Disease Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China
| | - Lizhen Xu
- Department of Biophysics and Disease Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China
| | - Xiaoying Chen
- Department of Biophysics and Disease Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China
| | - Fangyue Liu
- Department of Neurobiology and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi Shen
- Department of Neurobiology and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Shuangshuang Liu
- Core Facilities, Zhejiang University School of Medicine, Hangzhou, China
| | - Lidan Hu
- The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | | | | | | | - Han Wen
- DP Technology, Beijing, China.
- Institute for Advanced Algorithms Research, Shanghai, China.
- State Key Laboratory of Medical Proteomics, Shanghai, China.
- AI for Science Institute, Beijing, China.
- National Key Laboratory of Lead Druggability Research, Beijing, China.
| | - Fan Yang
- Department of Biophysics and Disease Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China.
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Polovitskaya MM, Rana T, Ullrich K, Murko S, Bierhals T, Vogt G, Stauber T, Kubisch C, Santer R, Jentsch TJ. Gain-of-function variants in CLCN7 cause hypopigmentation and lysosomal storage disease. J Biol Chem 2024; 300:107437. [PMID: 38838776 PMCID: PMC11261146 DOI: 10.1016/j.jbc.2024.107437] [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: 03/01/2024] [Revised: 05/08/2024] [Accepted: 05/23/2024] [Indexed: 06/07/2024] Open
Abstract
Together with its β-subunit OSTM1, ClC-7 performs 2Cl-/H+ exchange across lysosomal membranes. Pathogenic variants in either gene cause lysosome-related pathologies, including osteopetrosis and lysosomal storage. CLCN7 variants can cause recessive or dominant disease. Different variants entail different sets of symptoms. Loss of ClC-7 causes osteopetrosis and mostly neuronal lysosomal storage. A recently reported de novo CLCN7 mutation (p.Tyr715Cys) causes widespread severe lysosome pathology (hypopigmentation, organomegaly, and delayed myelination and development, "HOD syndrome"), but no osteopetrosis. We now describe two additional HOD individuals with the previously described p.Tyr715Cys and a novel p.Lys285Thr mutation, respectively. Both mutations decreased ClC-7 inhibition by PI(3,5)P2 and affected residues lining its binding pocket, and shifted voltage-dependent gating to less positive potentials, an effect partially conferred to WT subunits in WT/mutant heteromers. This shift predicts augmented pH gradient-driven Cl- uptake into vesicles. Overexpressing either mutant induced large lysosome-related vacuoles. This effect depended on Cl-/H+-exchange, as shown using mutants carrying uncoupling mutations. Fibroblasts from the p.Y715C patient also displayed giant vacuoles. This was not observed with p.K285T fibroblasts probably due to residual PI(3,5)P2 sensitivity. The gain of function caused by the shifted voltage-dependence of either mutant likely is the main pathogenic factor. Loss of PI(3,5)P2 inhibition will further increase current amplitudes, but may not be a general feature of HOD. Overactivity of ClC-7 induces pathologically enlarged vacuoles in many tissues, which is distinct from lysosomal storage observed with the loss of ClC-7 function. Osteopetrosis results from a loss of ClC-7, but osteoclasts remain resilient to increased ClC-7 activity.
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Affiliation(s)
- Maya M Polovitskaya
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Tanushka Rana
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; Graduate program of Humboldt-Universität zu Berlin and Graduate School of the Max Delbrück Centre for Molecular Medicine (MDC), Berlin, Germany
| | - Kurt Ullrich
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Simona Murko
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Tatjana Bierhals
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Guido Vogt
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Tobias Stauber
- Institute for Molecular Medicine, Medical School Hamburg (MSH), Hamburg, Germany
| | - Christian Kubisch
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - René Santer
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.
| | - Thomas J Jentsch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany.
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Cen J, Hu N, Shen J, Gao Y, Lu H. Pathological Functions of Lysosomal Ion Channels in the Central Nervous System. Int J Mol Sci 2024; 25:6565. [PMID: 38928271 PMCID: PMC11203704 DOI: 10.3390/ijms25126565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 06/06/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
Lysosomes are highly dynamic organelles that maintain cellular homeostasis and regulate fundamental cellular processes by integrating multiple metabolic pathways. Lysosomal ion channels such as TRPML1-3, TPC1/2, ClC6/7, CLN7, and TMEM175 mediate the flux of Ca2+, Cl-, Na+, H+, and K+ across lysosomal membranes in response to osmotic stimulus, nutrient-dependent signals, and cellular stresses. These ion channels serve as the crucial transducers of cell signals and are essential for the regulation of lysosomal biogenesis, motility, membrane contact site formation, and lysosomal homeostasis. In terms of pathophysiology, genetic variations in these channel genes have been associated with the development of lysosomal storage diseases, neurodegenerative diseases, inflammation, and cancer. This review aims to discuss the current understanding of the role of these ion channels in the central nervous system and to assess their potential as drug targets.
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Affiliation(s)
| | | | | | - Yongjing Gao
- Institute of Pain Medicine and Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226019, China; (J.C.); (N.H.); (J.S.)
| | - Huanjun Lu
- Institute of Pain Medicine and Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226019, China; (J.C.); (N.H.); (J.S.)
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Kimera L, Nadimpalli S, Kurup S, Sessions Cole F, Huang R, Sisco K, Ranaivo HR, Shinawi M, Dickson P, Mian A, Reynolds M. Case report: ocular manifestations of a gain-of-function mutation in CLCN6, a newly diagnosed disease. Ophthalmic Genet 2024; 45:271-274. [PMID: 38095064 PMCID: PMC11176260 DOI: 10.1080/13816810.2023.2291683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 10/31/2023] [Accepted: 11/30/2023] [Indexed: 02/23/2024]
Abstract
BACKGROUND In 2020, a new disease was reported by Polovitskaya et al., caused by a monoallelic, gain-of-function mutation in CLCN6, encoding the ClC-6 Cl-/H±exchanger. METHODS Here, we report the ophthalmic findings of one of the first three patients with this disease (the proband) and review the findings in the other two patients in the literature. RESULTS The CLCN6 gene is part of the voltage-dependent chloride channel protein family. It functions as either a chloride channel aiding in cell-volume regulation and acidification of intracellular organelles or as an antiporter, which are membrane proteins involved in the transport of molecules across a phospholipid membrane. This particular gene is found in late endosomes. Ion transport across endosome membranes is essential for endosomal function. The proband carried a de novo c.1658A>G (p.Tyr553Cys) mutation in CLCN6. The patient reported herein has a notable optic nerve appearance. The nerve initially appeared elevated. Over time, the optic nerve elevation appearance decreased, associated with progressive vision loss with a visual acuity of 20/470 at last follow-up. CONCLUSION While Clcn6-/- mice have been found to have a mild neuronal lysosomal storage phenotype, the three reported children with a de novo c.1658A>G (p.Tyr553Cys) variant displayed significant developmental delay and neurodegeneration.
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Affiliation(s)
- Lawrencia Kimera
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Sameera Nadimpalli
- Division of Ophthalmology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, USA
| | - Sudhi Kurup
- Division of Ophthalmology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, USA
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - F. Sessions Cole
- Department of Pediatrics, Division of Neonatal Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
- Department of Cell and Molecular Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Russell Huang
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Kathleen Sisco
- Department of Pediatrics, Division of Genetics and Genomic Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | | | - Marwan Shinawi
- Department of Pediatrics, Division of Genetics and Genomic Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Patricia Dickson
- Department of Pediatrics, Division of Genetics and Genomic Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Ali Mian
- Department of Radiology, Section of Neuroradiology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Margaret Reynolds
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
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8
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Kostritskaia Y, Klüssendorf M, Pan YE, Hassani Nia F, Kostova S, Stauber T. Physiological Functions of the Volume-Regulated Anion Channel VRAC/LRRC8 and the Proton-Activated Chloride Channel ASOR/TMEM206. Handb Exp Pharmacol 2024; 283:181-218. [PMID: 37468723 DOI: 10.1007/164_2023_673] [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] [Indexed: 07/21/2023]
Abstract
Volume-regulated anion channels (VRACs) and the acid-sensitive outwardly rectifying anion channel (ASOR) mediate flux of chloride and small organic anions. Although known for a long time, they were only recently identified at the molecular level. VRACs are heteromers consisting of LRRC8 proteins A to E. Combining the essential LRRC8A with different LRRC8 paralogues changes key properties of VRAC such as conductance or substrate selectivity, which is how VRACs are involved in multiple physiological functions including regulatory volume decrease, cell proliferation and migration, cell death, purinergic signalling, fat and glucose metabolism, insulin signalling, and spermiogenesis. VRACs are also involved in pathological conditions, such as the neurotoxic release of glutamate and aspartate. Certain VRACs are also permeable to larger, organic anions, including antibiotics and anti-cancer drugs, making them an interesting therapeutic target. ASOR, also named proton-activated chloride channel (PAC), is formed by TMEM206 homotrimers on the plasma membrane and on endosomal compartments where it mediates chloride flux in response to extracytosolic acidification and plays a role in the shrinking and maturation of macropinosomes. ASOR has been shown to underlie neuronal swelling which causes cell death after stroke as well as promoting the metastasis of certain cancers, making them intriguing therapeutic targets as well.
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Affiliation(s)
- Yulia Kostritskaia
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Malte Klüssendorf
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Yingzhou Edward Pan
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Fatemeh Hassani Nia
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Simona Kostova
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Tobias Stauber
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany.
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9
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Bose S, de Heus C, Kennedy ME, Wang F, Jentsch TJ, Klumperman J, Stauber T. Impaired Autophagic Clearance with a Gain-of-Function Variant of the Lysosomal Cl -/H + Exchanger ClC-7. Biomolecules 2023; 13:1799. [PMID: 38136669 PMCID: PMC10742274 DOI: 10.3390/biom13121799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/04/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
ClC-7 is a ubiquitously expressed voltage-gated Cl-/H+ exchanger that critically contributes to lysosomal ion homeostasis. Together with its β-subunit Ostm1, ClC-7 localizes to lysosomes and to the ruffled border of osteoclasts, where it supports the acidification of the resorption lacuna. Loss of ClC-7 or Ostm1 leads to osteopetrosis accompanied by accumulation of storage material in lysosomes and neurodegeneration. Interestingly, not all osteopetrosis-causing CLCN7 mutations from patients are associated with a loss of ion transport. Some rather result in an acceleration of voltage-dependent ClC-7 activation. Recently, a gain-of-function variant, ClC-7Y715C, that yields larger ion currents upon heterologous expression, was identified in two patients with neurodegeneration, organomegaly and albinism. However, neither the patients nor a mouse model that carried the equivalent mutation developed osteopetrosis, although expression of ClC-7Y715C induced the formation of enlarged intracellular vacuoles. Here, we investigated how, in transfected cells with mutant ClC-7, the substitution of this tyrosine impinged on the morphology and function of lysosomes. Combinations of the tyrosine mutation with mutations that either uncouple Cl- from H+ counter-transport or strongly diminish overall ion currents were used to show that increased ClC-7 Cl-/H+ exchange activity is required for the formation of enlarged vacuoles by membrane fusion. Degradation of endocytosed material was reduced in these compartments and resulted in an accumulation of lysosomal storage material. In cells expressing the ClC-7 gain-of-function mutant, autophagic clearance was largely impaired, resulting in a build-up of autophagic material.
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Affiliation(s)
- Shroddha Bose
- Institute for Molecular Medicine, MSH Medical School Hamburg, 20457 Hamburg, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Cecilia de Heus
- Center for Molecular Medicine/Cell Biology, University Medical Center (UMC), 3584 CX Utrecht, The Netherlands
| | - Mary E. Kennedy
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Fan Wang
- Institute for Molecular Medicine, MSH Medical School Hamburg, 20457 Hamburg, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Thomas J. Jentsch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Judith Klumperman
- Center for Molecular Medicine/Cell Biology, University Medical Center (UMC), 3584 CX Utrecht, The Netherlands
| | - Tobias Stauber
- Institute for Molecular Medicine, MSH Medical School Hamburg, 20457 Hamburg, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
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10
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Coppola MA, Gavazzo P, Zanardi I, Tettey-Matey A, Liantonio A, Fong P, Pusch M. Distinct ClC-6 and ClC-7 Cl - sensitivities provide insight into ClC-7's role in lysosomal Cl - homeostasis. J Physiol 2023; 601:5635-5653. [PMID: 37937509 PMCID: PMC10842065 DOI: 10.1113/jp285431] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 10/16/2023] [Indexed: 11/09/2023] Open
Abstract
ClC-6 and ClC-7 are closely related, intracellular Cl- /H+ antiporters belonging to the CLC family of channels and transporters. They localize to acidic late endosomes and lysosomes and probably function in ionic homeostasis of these contiguous compartments. ClC-7 transport function requires association with the accessory protein Ostm1, whereas ClC-6 transport does not. To elucidate their roles in endo-lysosomes, we measured Cl- - and pH-dependences of over-expressed wild-type ClC-6 and ClC-7, as well as disease-associated mutants, using high-resolution recording protocols. Lowering extracellular Cl- (corresponding to luminal Cl- in endo-lysosomes) reduced ClC-6 currents, whereas it increased transport activity of ClC-7/Ostm1. Low extracellular Cl- activated ClC-7/Ostm 1 under acidic extracellular conditions, as well as under conditions of low intracellular chloride. Activation is conserved in ClC-7Y713C , a variant displaying disrupted PI(3,5)P2 inhibition. Detailed biophysical analysis of disease-associated ClC-6 and ClC-7 gain-of-function (GoF) variants, ClC-6Y553C and ClC-7Y713C , and the ClC-7Y577C and ClC-6Y781C correlates, identified additional functional nuances distinguishing ClC-6 and ClC-7. ClC-7Y577C recapitulated GoF produced by ClC-6Y553C . ClC-6Y781C displayed transport activation qualitatively similar to ClC-7Y713C , although current density did not differ from that of wild-type ClC-6. Finally, rClC-7R760Q , homologous to hClC-7R762Q , an osteopetrosis variant with fast gating kinetics, appeared indifferent to extracellular Cl- , identifying altered Cl- sensitivity as a plausible mechanism underlying disease. Collectively, the present studies underscore the distinct roles of ClC-6 and ClC-7 within the context of their respective localization to late endosomes and lysosomes. In particular, we suggest the atypical inhibition of ClC-7 by luminal Cl- serves to limit excessive intraluminal Cl- accumulation. KEY POINTS: ClC-6 and ClC-7 are late endosomal and lysosomal 2 Cl- /1 H+ exchangers, respectively. When targeted to the plasma membrane, both activate slowly at positive voltages. ClC-6 activity is decreased in low extracellular (i.e. luminal) chloride, whereas ClC-7 is activated by low luminal chloride, even at acidic pH. The functional gain-of-function phenotypes of the ClC-6 and ClC-7 disease mutations ClC-6Y553C and ClC-7Y715C are maintained when introduced in their respective homologues, ClC-7Y577C and ClC-6Y781C , with all mutations retaining chloride dependence of the respective wild type (WT). An osteopetrosis mutation of ClC-7 displaying fast gating kinetics (R762Q) was less sensitive to extracellular chloride compared to WT. The opposing substrate dependences of ClC-6 and ClC-7 Cl- / H+ exchangers point to non-overlapping physiological functions, leading us to propose that inhibition of ClC-7 by luminal chloride and protons serves to prevent osmotic stress imposed by hyper-accumulation of chloride.
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Affiliation(s)
- Maria Antonietta Coppola
- Institute of Biophysics, CNR, Genoa, Italy
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, Bari, Italy
| | | | | | | | - Antonella Liantonio
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, Bari, Italy
| | - Peying Fong
- Department of Anatomy and Physiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA
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11
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Picollo A. Vesicular CLC chloride/proton exchangers in health and diseases. Front Pharmacol 2023; 14:1295068. [PMID: 38027030 PMCID: PMC10662042 DOI: 10.3389/fphar.2023.1295068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Chloride is one of the most abundant anions in the human body; it is implicated in several physiological processes such as the transmission of action potentials, transepithelial salt transport, maintenance of cellular homeostasis, regulation of osmotic pressure and intracellular pH, and synaptic transmission. The balance between the extracellular and intracellular chloride concentrations is controlled by the interplay of ion channels and transporters embedded in the cellular membranes. Vesicular members of the CLC chloride protein family (vCLCs) are chloride/proton exchangers expressed in the membrane of the intracellular organelles, where they control vesicular acidification and luminal chloride concentration. It is well known that mutations in CLCs cause bone, kidney, and lysosomal genetic diseases. However, the role of CLC exchangers in neurological disorders is only now emerging with the identification of pathogenic CLCN gene variants in patients with severe neuronal and intellectual dysfunctions. This review will provide an overview of the recent advances in understanding the role of the vesicular CLC chloride/proton exchangers in human pathophysiology.
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Affiliation(s)
- Alessandra Picollo
- Institute of Biophysics, National Research Council, Genova, Italy
- RAISE Ecosystem, Genova, Italy
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12
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Zhang B, Zhang S, Polovitskaya MM, Yi J, Ye B, Li R, Huang X, Yin J, Neuens S, Balfroid T, Soblet J, Vens D, Aeby A, Li X, Cai J, Song Y, Li Y, Tartaglia M, Li Y, Jentsch TJ, Yang M, Liu Z. Molecular basis of ClC-6 function and its impairment in human disease. SCIENCE ADVANCES 2023; 9:eadg4479. [PMID: 37831762 PMCID: PMC10575590 DOI: 10.1126/sciadv.adg4479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Accepted: 09/08/2023] [Indexed: 10/15/2023]
Abstract
ClC-6 is a late endosomal voltage-gated chloride-proton exchanger that is predominantly expressed in the nervous system. Mutated forms of ClC-6 are associated with severe neurological disease. However, the mechanistic role of ClC-6 in normal and pathological states remains largely unknown. Here, we present cryo-EM structures of ClC-6 that guided subsequent functional studies. Previously unrecognized ATP binding to cytosolic ClC-6 domains enhanced ion transport activity. Guided by a disease-causing mutation (p.Y553C), we identified an interaction network formed by Y553/F317/T520 as potential hotspot for disease-causing mutations. This was validated by the identification of a patient with a de novo pathogenic variant p.T520A. Extending these findings, we found contacts between intramembrane helices and connecting loops that modulate the voltage dependence of ClC-6 gating and constitute additional candidate regions for disease-associated gain-of-function mutations. Besides providing insights into the structure, function, and regulation of ClC-6, our work correctly predicts hotspots for CLCN6 mutations in neurodegenerative disorders.
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Affiliation(s)
- Bing Zhang
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, 201204 Shanghai, China
| | - Sensen Zhang
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084 Beijing, China
| | - Maya M. Polovitskaya
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), 13125 Berlin, Germany
| | - Jingbo Yi
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084 Beijing, China
| | - Binglu Ye
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, 201204 Shanghai, China
| | - Ruochong Li
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084 Beijing, China
| | - Xueying Huang
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, 201204 Shanghai, China
| | - Jian Yin
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084 Beijing, China
| | - Sebastian Neuens
- Department of Genetics, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Tom Balfroid
- Department of Pediatric Neurology, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Julie Soblet
- Department of Genetics, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Department of Genetics, Hôpital Erasme, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Daphné Vens
- Pediatric Intensive Care Unit, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Alec Aeby
- Department of Pediatric Neurology, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Xiaoling Li
- Wuya College of Innovation, Shenyang Pharmaceutical University, 110016 Shenyang, China
| | - Jinjin Cai
- Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203 Shanghai, China
| | - Yingcai Song
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, 201204 Shanghai, China
| | - Yuanxi Li
- Institute for Cognitive Neurodynamics, School of Mathematics, East China University of Science and Technology, 200237 Shanghai, China
| | - Marco Tartaglia
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Yang Li
- Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203 Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Thomas J. Jentsch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), 13125 Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Maojun Yang
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084 Beijing, China
- Cryo-EM Facility Center, Southern University of Science & Technology, 518055 Shenzhen, Guangdong, China
| | - Zhiqiang Liu
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, 201204 Shanghai, China
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13
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Cao X, Lenk GM, Mikusevic V, Mindell JA, Meisler MH. The chloride antiporter CLCN7 is a modifier of lysosome dysfunction in FIG 4 and VAC14 mutants. PLoS Genet 2023; 19:e1010800. [PMID: 37363915 DOI: 10.1371/journal.pgen.1010800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 05/26/2023] [Indexed: 06/28/2023] Open
Abstract
The phosphatase FIG 4 and the scaffold protein VAC14 function in the biosynthesis of PI(3,5)P2, a signaling lipid that inhibits the lysosomal chloride transporter ClC-7. Loss-of-function mutations of FIG 4 and VAC14 reduce PI(3,5)P2 and result in lysosomal disorders characterized by accumulation of enlarged lysosomes and neurodegeneration. Similarly, a gain of function mutation of CLCN7 encoding ClC-7 also results in enlarged lysosomes. We therefore tested the ability of reduced CLCN7 expression to compensate for loss of FIG 4 or VAC14. Knock-out of CLCN7 corrected lysosomal swelling and partially corrected lysosomal hyperacidification in FIG 4 null cell cultures. Knockout of the related transporter CLCN6 (ClC-6) in FIG 4 null cells did not affect the lysosome phenotype. In the Fig 4 null mouse, reduction of ClC-7 by expression of the dominant negative CLCN7 variant p.Gly215Arg improved growth and neurological function and increased lifespan by 20%. These observations demonstrate a role for the CLCN7 chloride transporter in pathogenesis of FIG 4 and VAC14 disorders. Reduction of CLCN7 provides a new target for treatment of FIG 4 and VAC14 deficiencies that lack specific therapies, such as Charcot-Marie-Tooth Type 4J and Yunis-Varón syndrome.
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Affiliation(s)
- Xu Cao
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Guy M Lenk
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Vedrana Mikusevic
- Membrane Transport Biophysics Section, National Institutes of Neurological Disorders and Stroke, Bethesda, Maryland, United States of America
| | - Joseph A Mindell
- Membrane Transport Biophysics Section, National Institutes of Neurological Disorders and Stroke, Bethesda, Maryland, United States of America
| | - Miriam H Meisler
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
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14
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Coppola MA, Tettey-Matey A, Imbrici P, Gavazzo P, Liantonio A, Pusch M. Biophysical Aspects of Neurodegenerative and Neurodevelopmental Disorders Involving Endo-/Lysosomal CLC Cl -/H + Antiporters. Life (Basel) 2023; 13:1317. [PMID: 37374100 DOI: 10.3390/life13061317] [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: 05/22/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
Endosomes and lysosomes are intracellular vesicular organelles with important roles in cell functions such as protein homeostasis, clearance of extracellular material, and autophagy. Endolysosomes are characterized by an acidic luminal pH that is critical for proper function. Five members of the gene family of voltage-gated ChLoride Channels (CLC proteins) are localized to endolysosomal membranes, carrying out anion/proton exchange activity and thereby regulating pH and chloride concentration. Mutations in these vesicular CLCs cause global developmental delay, intellectual disability, various psychiatric conditions, lysosomal storage diseases, and neurodegeneration, resulting in severe pathologies or even death. Currently, there is no cure for any of these diseases. Here, we review the various diseases in which these proteins are involved and discuss the peculiar biophysical properties of the WT transporter and how these properties are altered in specific neurodegenerative and neurodevelopmental disorders.
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Affiliation(s)
- Maria Antonietta Coppola
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", 70125 Bari, Italy
| | | | - Paola Imbrici
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", 70125 Bari, Italy
| | - Paola Gavazzo
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy
| | - Antonella Liantonio
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", 70125 Bari, Italy
| | - Michael Pusch
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy
- RAISE Ecosystem, 16149 Genova, Italy
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15
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Palmer EE, Pusch M, Picollo A, Forwood C, Nguyen MH, Suckow V, Gibbons J, Hoff A, Sigfrid L, Megarbane A, Nizon M, Cogné B, Beneteau C, Alkuraya FS, Chedrawi A, Hashem MO, Stamberger H, Weckhuysen S, Vanlander A, Ceulemans B, Rajagopalan S, Nunn K, Arpin S, Raynaud M, Motter CS, Ward-Melver C, Janssens K, Meuwissen M, Beysen D, Dikow N, Grimmel M, Haack TB, Clement E, McTague A, Hunt D, Townshend S, Ward M, Richards LJ, Simons C, Costain G, Dupuis L, Mendoza-Londono R, Dudding-Byth T, Boyle J, Saunders C, Fleming E, El Chehadeh S, Spitz MA, Piton A, Gerard B, Abi Warde MT, Rea G, McKenna C, Douzgou S, Banka S, Akman C, Bain JM, Sands TT, Wilson GN, Silvertooth EJ, Miller L, Lederer D, Sachdev R, Macintosh R, Monestier O, Karadurmus D, Collins F, Carter M, Rohena L, Willemsen MH, Ockeloen CW, Pfundt R, Kroft SD, Field M, Laranjeira FER, Fortuna AM, Soares AR, Michaud V, Naudion S, Golla S, Weaver DD, Bird LM, Friedman J, Clowes V, Joss S, Pölsler L, Campeau PM, Blazo M, Bijlsma EK, Rosenfeld JA, Beetz C, Powis Z, McWalter K, Brandt T, Torti E, Mathot M, Mohammad SS, Armstrong R, Kalscheuer VM. Functional and clinical studies reveal pathophysiological complexity of CLCN4-related neurodevelopmental condition. Mol Psychiatry 2023; 28:668-697. [PMID: 36385166 PMCID: PMC9908558 DOI: 10.1038/s41380-022-01852-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 10/10/2022] [Accepted: 10/21/2022] [Indexed: 11/17/2022]
Abstract
Missense and truncating variants in the X-chromosome-linked CLCN4 gene, resulting in reduced or complete loss-of-function (LOF) of the encoded chloride/proton exchanger ClC-4, were recently demonstrated to cause a neurocognitive phenotype in both males and females. Through international clinical matchmaking and interrogation of public variant databases we assembled a database of 90 rare CLCN4 missense variants in 90 families: 41 unique and 18 recurrent variants in 49 families. For 43 families, including 22 males and 33 females, we collated detailed clinical and segregation data. To confirm causality of variants and to obtain insight into disease mechanisms, we investigated the effect on electrophysiological properties of 59 of the variants in Xenopus oocytes using extended voltage and pH ranges. Detailed analyses revealed new pathophysiological mechanisms: 25% (15/59) of variants demonstrated LOF, characterized by a "shift" of the voltage-dependent activation to more positive voltages, and nine variants resulted in a toxic gain-of-function, associated with a disrupted gate allowing inward transport at negative voltages. Functional results were not always in line with in silico pathogenicity scores, highlighting the complexity of pathogenicity assessment for accurate genetic counselling. The complex neurocognitive and psychiatric manifestations of this condition, and hitherto under-recognized impacts on growth, gastrointestinal function, and motor control are discussed. Including published cases, we summarize features in 122 individuals from 67 families with CLCN4-related neurodevelopmental condition and suggest future research directions with the aim of improving the integrated care for individuals with this diagnosis.
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Affiliation(s)
- Elizabeth E Palmer
- Centre for Clinical Genetics, Sydney Children's Hospital Network, Randwick, NSW, Australia.
- Discipline of Paediatrics and Child Health, Faculty of Medicine and Health, University of New South Wales, Randwick, NSW, Australia.
| | | | | | - Caitlin Forwood
- Centre for Clinical Genetics, Sydney Children's Hospital Network, Randwick, NSW, Australia
| | - Matthew H Nguyen
- Discipline of Paediatrics and Child Health, Faculty of Medicine and Health, University of New South Wales, Randwick, NSW, Australia
- Department of Clinical Genetics, Liverpool Hospital, Liverpool, NSW, Australia
| | - Vanessa Suckow
- Max Planck Institute for Molecular Genetics, Group Development and Disease, Berlin, Germany
| | - Jessica Gibbons
- Max Planck Institute for Molecular Genetics, Group Development and Disease, Berlin, Germany
| | - Alva Hoff
- Istituto di Biofisica, CNR, Genova, Italy
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, 581 83, Sweden
| | - Lisa Sigfrid
- Istituto di Biofisica, CNR, Genova, Italy
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, 581 83, Sweden
| | - Andre Megarbane
- Department of Human Genetics, Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
- Institut Jerome Lejeune, Paris, France
| | - Mathilde Nizon
- Service de Génétique Médicale, CHU de Nantes, Nantes Université, Nantes, France
- Nantes Université, CNRS, INSERM, l'Institut du Thorax, Nantes, France
| | - Benjamin Cogné
- Service de Génétique Médicale, CHU de Nantes, Nantes Université, Nantes, France
- Nantes Université, CNRS, INSERM, l'Institut du Thorax, Nantes, France
| | - Claire Beneteau
- Service de Génétique Médicale, CHU de Nantes, Nantes Université, Nantes, France
| | - Fowzan S Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Aziza Chedrawi
- Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais O Hashem
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hannah Stamberger
- Applied and Translational Neurogenomics Group, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium
- Neurology Department, Antwerp University Hospital, Antwerp, Belgium
| | - Sarah Weckhuysen
- Applied and Translational Neurogenomics Group, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium
- Neurology Department, Antwerp University Hospital, Antwerp, Belgium
- Translational Neurosciences, Faculty of Medicine and Health Science, University of Antwerp, Antwerp, Belgium
| | - Arnaud Vanlander
- Department of Child Neurology & Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Berten Ceulemans
- Department of Pediatric Neurology, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Sulekha Rajagopalan
- Department of Clinical Genetics, Liverpool Hospital, Liverpool, NSW, Australia
| | - Kenneth Nunn
- Children's Hospital at Westmead, Sydney Children's Hospitals Network, Sydney, Australia
| | - Stéphanie Arpin
- Service de Génétique Clinique, Centre Hospitalier Régional Universitaire de Tours, Tours, France
| | - Martine Raynaud
- Service de Génétique Clinique, Centre Hospitalier Régional Universitaire de Tours, Tours, France
| | | | | | - Katrien Janssens
- Center of Medical Genetics, University Hospital Antwerp/University of Antwerp, Edegem, Belgium
| | - Marije Meuwissen
- Center of Medical Genetics, University Hospital Antwerp/University of Antwerp, Edegem, Belgium
| | - Diane Beysen
- Department of Pediatric Neurology, University Hospital Antwerp/University of Antwerp, Edegem, Belgium
| | - Nicola Dikow
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Mona Grimmel
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Emma Clement
- Department of Clinical Genetics, Great Ormond Street Hospital for Children, London, UK
| | - Amy McTague
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - David Hunt
- Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK
| | - Sharron Townshend
- Genetic Services of WA, King Edward Memorial Hospital, Subiaco, WA, Australia
| | - Michelle Ward
- Genetic Services of WA, King Edward Memorial Hospital, Subiaco, WA, Australia
| | - Linda J Richards
- Department of Neuroscience, Washington University in St Louis School of Medicine, St Louis, MI, USA
- The University of Queensland, Queensland Brain Institute, St Lucia, QLD, Australia
| | - Cas Simons
- Centre for Population Genomics, Murdoch Children's Research Institute, Melbourne, Australia
- Garvan Institute of Medical Research, UNSW, Sydney, NSW, Australia
| | - Gregory Costain
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada
| | - Lucie Dupuis
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada
| | - Roberto Mendoza-Londono
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada
| | - Tracy Dudding-Byth
- Genetics of Learning Disability Service, Newcastle, NSW, Australia
- University of Newcastle Grow Up Well Priority Research Centre, Newcastle, NSW, Australia
| | - Jackie Boyle
- Genetics of Learning Disability Service, Newcastle, NSW, Australia
| | - Carol Saunders
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital and Clinics, MI, Kansas City, USA
- Kansas City School of Medicine, University of Missouri, Kansas City, MI, USA
| | - Emily Fleming
- Division of Clinical Genetics, Children's Mercy Hospital and Clinics, Kansas City, MI, USA
| | - Salima El Chehadeh
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- Laboratoire de Génétique Médicale, UMRS_1112, Institut de Génétique Médicale d'Alsace (IGMA), Université de Strasbourg et INSERM, Strasbourg, France
| | - Marie-Aude Spitz
- Service de Pédiatrie, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Amelie Piton
- Laboratoires de Diagnostic Génétique, Institut de Génétique Médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Nouvel Hôpital Civil, Strasbourg, France
| | - Bénédicte Gerard
- Laboratoires de Diagnostic Génétique, Institut de Génétique Médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Nouvel Hôpital Civil, Strasbourg, France
| | - Marie-Thérèse Abi Warde
- Service de Pédiatrie, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- Pediatric Neurology Department, CHU de Strasbourg, Strasbourg, France
| | - Gillian Rea
- Northern Ireland Regional Genetics Service, Belfast, Northern Ireland
| | - Caoimhe McKenna
- Northern Ireland Regional Genetics Service, Belfast, Northern Ireland
| | - Sofia Douzgou
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Siddharth Banka
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Cigdem Akman
- Department of Neurology, Division of Child Neurology, Columbia University Irving Medical Center, New York, USA
| | - Jennifer M Bain
- Department of Neurology, Division of Child Neurology, Columbia University Irving Medical Center, New York, USA
| | - Tristan T Sands
- Department of Neurology, Division of Child Neurology, Columbia University Irving Medical Center, New York, USA
| | - Golder N Wilson
- Texas Tech Health Sciences Center Lubbock and KinderGenome Medical Genetics, Dallas, TX, USA
| | | | | | - Damien Lederer
- Centre de Génétique Humaine, Institut de Pathologie et de Génétique ASBL, Gosselies, Belgium
| | - Rani Sachdev
- Centre for Clinical Genetics, Sydney Children's Hospital Network, Randwick, NSW, Australia
- Discipline of Paediatrics and Child Health, Faculty of Medicine and Health, University of New South Wales, Randwick, NSW, Australia
| | - Rebecca Macintosh
- Centre for Clinical Genetics, Sydney Children's Hospital Network, Randwick, NSW, Australia
- Discipline of Paediatrics and Child Health, Faculty of Medicine and Health, University of New South Wales, Randwick, NSW, Australia
| | - Olivier Monestier
- Centre de Génétique Humaine, Institut de Pathologie et de Génétique ASBL, Gosselies, Belgium
| | - Deniz Karadurmus
- Centre de Génétique Humaine, Institut de Pathologie et de Génétique ASBL, Gosselies, Belgium
| | - Felicity Collins
- Department of Medical Genomics/Clinical Genetics, Royal Prince Alfred Hospital, Camperdown, Sydney, NSW, Australia
| | - Melissa Carter
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
| | - Luis Rohena
- Division of Medical Genetics, Department of Pediatrics, San Antonio Military Medical Center, San Antonio, TX, USA
- Department of Pediatrics, Long School of Medicine-UT Health San Antonio, San Antonio, TX, USA
| | - Marjolein H Willemsen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Charlotte W Ockeloen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sanne D Kroft
- Pluryn, Residential Care Setting, Groesbeek, The Netherlands
| | - Michael Field
- Genetics of Learning Disability Service, Newcastle, NSW, Australia
| | - Francisco E R Laranjeira
- Centro de Genética Médica Jacinto Magalhães, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Ana M Fortuna
- Unit for Multidisciplinary Research in Biomedicine, School of Medicine and Biomedical Sciences, Porto University, Porto, Portugal
| | - Ana R Soares
- Unit for Multidisciplinary Research in Biomedicine, School of Medicine and Biomedical Sciences, Porto University, Porto, Portugal
| | - Vincent Michaud
- Service de Génétique Médicale, CHU Bordeaux, Bordeaux, France
- INSERM U1211, Laboratoire Maladies Rares: Génétique et Métabolisme, Bordeaux, Univ., Bordeaux, France
| | - Sophie Naudion
- Service de Génétique Médicale, CHU Bordeaux, Bordeaux, France
| | - Sailaja Golla
- Child Neurology and Neurodevelopmental Medicine Thompson Autism Center, CHOC Hospital, Orange County, CA, USA
| | - David D Weaver
- Indiana University School of Medicine, Indianapolis, USA
| | - Lynne M Bird
- University of California, San Diego, Rady Children's Hospital San Diego, San Diego, CA, USA
| | - Jennifer Friedman
- University of California, San Diego, Rady Children's Hospital San Diego, San Diego, CA, USA
| | - Virginia Clowes
- North West Thames Regional Genetics Service, London North West University Healthcare NHS Trust, Harrow, London, UK
- Imperial College London, London, UK
| | - Shelagh Joss
- West of Scotland Centre for Genomic Medicine, Queen Elizabeth University Hospital, Glasgow, UK
| | - Laura Pölsler
- Centrum Medische Genetica, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Philippe M Campeau
- CHU Sainte-Justine Research Center, University of Montreal, Montreal, QC, Canada
| | - Maria Blazo
- Division Clinical Genetics Texas A&M University Health Science Center, College Station, TX, USA
| | - Emilia K Bijlsma
- Department of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Jill A Rosenfeld
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Baylor Genetics Laboratories, Houston, TX, USA
| | | | - Zöe Powis
- Clinical Genomics, Ambry Genetics, Aliso Viejo, CA, USA
| | | | | | | | | | - Shekeeb S Mohammad
- Children's Hospital at Westmead, Sydney Children's Hospitals Network, Sydney, Australia
- Children's Hospital at Westmead, Sydney Children's Hospitals Network, Sydney, NSW, Australia
| | - Ruth Armstrong
- East Anglian Medical Genetics Service, Clinical Genetics, Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, UK
| | - Vera M Kalscheuer
- Max Planck Institute for Molecular Genetics, Group Development and Disease, Berlin, Germany.
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Lepiarczyk E, Paukszto Ł, Wiszpolska M, Łopieńska-Biernat E, Bossowska A, Majewski MK, Majewska M. Molecular Influence of Resiniferatoxin on the Urinary Bladder Wall Based on Differential Gene Expression Profiling. Cells 2023; 12:cells12030462. [PMID: 36766804 PMCID: PMC9914288 DOI: 10.3390/cells12030462] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Resiniferatoxin (RTX) is a potent capsaicin analog used as a drug for experimental therapy to treat neurogenic disorders associated with enhanced nociceptive transmission, including lower urinary tract symptoms. The present study, for the first time, investigated the transcriptomic profile of control and RTX-treated porcine urinary bladder walls. We applied multistep bioinformatics and discovered 129 differentially expressed genes (DEGs): 54 upregulated and 75 downregulated. Metabolic pathways analysis revealed five significant Kyoto Encyclopedia of Genes and Genomes (KEGG) items ('folate biosynthesis', 'metabolic pathways', 'sulfur relay system', 'sulfur metabolism' and 'serotonergic synapse') that were altered after RTX intravesical administration. A thorough analysis of the detected DEGs indicated that RTX treatment influenced the signaling pathways regulating nerve growth, myelination, axon specification, and elongation. Many of the revealed DEGs are involved in the nerve degeneration process; however, some of them were implicated in the initiation of neuroprotective mechanisms. Interestingly, RTX intravesical installation was followed by changes in the expression of genes involved in synaptic plasticity and neuromodulation, including 5-HT, H2S, glutamate, and GABA transmission. The obtained results suggest that the toxin may exert a therapeutic, antinociceptive effect not only by acting on TRPV1 receptors.
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Affiliation(s)
- Ewa Lepiarczyk
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury in Olsztyn, 10-082 Olsztyn, Poland
- Correspondence: ; Tel.: +48-89-524-53-34; Fax: +48-89-524-53-07
| | - Łukasz Paukszto
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, 10-727 Olsztyn, Poland
| | - Marta Wiszpolska
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury in Olsztyn, 10-082 Olsztyn, Poland
| | - Elżbieta Łopieńska-Biernat
- Department of Biochemistry, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland
| | - Agnieszka Bossowska
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury in Olsztyn, 10-082 Olsztyn, Poland
| | - Mariusz Krzysztof Majewski
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury in Olsztyn, 10-082 Olsztyn, Poland
| | - Marta Majewska
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury in Olsztyn, 10-082 Olsztyn, Poland
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17
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Kisaretova P, Tsybko A, Bondar N, Reshetnikov V. Molecular Abnormalities in BTBR Mice and Their Relevance to Schizophrenia and Autism Spectrum Disorders: An Overview of Transcriptomic and Proteomic Studies. Biomedicines 2023; 11:289. [PMID: 36830826 PMCID: PMC9953015 DOI: 10.3390/biomedicines11020289] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/22/2023] Open
Abstract
Animal models of psychopathologies are of exceptional interest for neurobiologists because these models allow us to clarify molecular mechanisms underlying the pathologies. One such model is the inbred BTBR strain of mice, which is characterized by behavioral, neuroanatomical, and physiological hallmarks of schizophrenia (SCZ) and autism spectrum disorders (ASDs). Despite the active use of BTBR mice as a model object, the understanding of the molecular features of this strain that cause the observed behavioral phenotype remains insufficient. Here, we analyzed recently published data from independent transcriptomic and proteomic studies on hippocampal and corticostriatal samples from BTBR mice to search for the most consistent aberrations in gene or protein expression. Next, we compared reproducible molecular signatures of BTBR mice with data on postmortem samples from ASD and SCZ patients. Taken together, these data helped us to elucidate brain-region-specific molecular abnormalities in BTBR mice as well as their relevance to the anomalies seen in ASDs or SCZ in humans.
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Affiliation(s)
- Polina Kisaretova
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Prospekt Akad. Lavrentyeva 10, Novosibirsk 630090, Russia
- Department of Natural Sciences, Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia
| | - Anton Tsybko
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Prospekt Akad. Lavrentyeva 10, Novosibirsk 630090, Russia
| | - Natalia Bondar
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Prospekt Akad. Lavrentyeva 10, Novosibirsk 630090, Russia
| | - Vasiliy Reshetnikov
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Prospekt Akad. Lavrentyeva 10, Novosibirsk 630090, Russia
- Department of Biotechnology, Sirius University of Science and Technology, 1 Olympic Avenue, Sochi 354340, Russia
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18
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Klemens CA, Dissanayake LV, Levchenko V, Zietara A, Palygin O, Staruschenko A. Modulation of blood pressure regulatory genes in the Agtrap-Plod1 locus associated with a deletion in Clcn6. Physiol Rep 2022; 10:e15417. [PMID: 35927940 PMCID: PMC9353118 DOI: 10.14814/phy2.15417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023] Open
Abstract
The AGTRAP-PLOD1 locus is a conserved gene cluster containing several blood pressure regulatory genes, including CLCN6, MTHFR, NPPA, and NPPB. Previous work revealed that knockout of Clcn6 on the Dahl Salt-Sensitive (SS) rat background (SS-Clcn6) resulted in lower diastolic blood pressure compared to SS-WT rats. Additionally, a recent study found sickle cell anemia patients with mutations in CLCN6 had improved survival and reduced stroke risk. We investigated whether loss of Clcn6 would delay the mortality of Dahl SS rats on an 8% NaCl (HS) diet. No significant difference in survival was found. The ability of Clcn6 to affect mRNA expression of nearby Mthfr, Nppa, and Nppb genes was also tested. On normal salt (0.4% NaCl, NS) diets, renal Mthfr mRNA and protein expression were significantly increased in the SS-Clcn6 rats. MTHFR reduces homocysteine to methionine, but no differences in circulating homocysteine levels were detected. Nppa mRNA levels in cardiac tissue from SS-Clcn6 rat in both normotensive and hypertensive conditions were significantly reduced compared to SS-WT. Nppb mRNA expression in SS-Clcn6 rats on a NS diet was also substantially decreased. Heightened Mthfr expression would be predicted to be protective; however, diminished Nppa and Nppb expression could be deleterious and by preventing or blunting vasodilation, natriuresis, and diuresis that ought to normally occur to offset blood pressure increases. The conserved nature of this genetic locus in humans and rats suggests more studies are warranted to understand how mutations in and around these genes may be influencing the expression of their neighbors.
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Affiliation(s)
- Christine A. Klemens
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- Hypertension and Kidney Research CenterUniversity of South FloridaTampaFloridaUSA
| | - Lashodya V. Dissanayake
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- Department of PhysiologyMedical College of WisconsinMilwaukeeWisconsinUSA
| | - Vladislav Levchenko
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
| | - Adrian Zietara
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- Department of PhysiologyMedical College of WisconsinMilwaukeeWisconsinUSA
| | - Oleg Palygin
- Department of MedicineMedical University of South CarolinaCharlestonSouth CarolinaUSA
| | - Alexander Staruschenko
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- Hypertension and Kidney Research CenterUniversity of South FloridaTampaFloridaUSA
- James A. Haley Veterans' HospitalTampaFloridaUSA
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19
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Kobertz WR. Want to hear ClC-6 sing? Push your amp to eleven. J Physiol 2022; 600:2019-2020. [PMID: 35286714 DOI: 10.1113/jp283060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- William R Kobertz
- Department of Biochemistry and Molecular Pharmacology, Programs in Neuroscience and Chemical Biology, UMass Chan Medical School, 364 Plantation Street, Worcester, MA, 01605-2324
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20
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Zifarelli G, Pusch M, Fong P. Altered voltage-dependence of slowly activating chloride-proton antiport by late endosomal ClC-6 explains distinct neurological disorders. J Physiol 2022; 600:2147-2164. [PMID: 35262198 DOI: 10.1113/jp282737] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/01/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Ionic composition and pH within intracellular compartments, such as endo-lysosomes, rely on the activity of chloride/proton transporters including ClC-6. Distinct CLCN6 mutations previously were found in individuals with neurodegenerative disease, and also putatively associated with neuronal ceroidal lipofuscinosis. Limited knowledge of wild-type ClC-6 transport function impedes understanding of mechanisms underlying these conditions. We resolved transient and transport currents that permit measurement of voltage- and pH- dependences, as well as kinetics, for wild-type and disease-associated mutant ClC-6s. These findings define wild-type ClC-6 function robustly, and reveal how alterations of the slow activation gating of the transporter cause different kinds of neurological diseases. ABSTRACT ClC-6 is an intracellularly localized member of the CLC family of chloride transport proteins. It presumably functions in the endo-lysosomal compartment as a chloride-proton antiporter, despite a paucity of biophysical studies in direct support. Observations of lysosomal storage disease, as well as neurodegenerative disorders, emerge with its disruption by knockout or mutation, respectively. An incomplete understanding of wild type ClC-6 function obscures clear mechanistic insight into disease etiology. Here, high-resolution recording protocols that incorporate extreme voltage pulses permit detailed biophysical measurement and analysis of transient capacitive, as well as ionic transport currents. This approach reveals that wild type ClC-6 activation and transport require depolarization to voltages beyond 140 mV. Mutant Y553C associated with early-onset neurodegeneration exerts gain-of-function by shifting the half-maximal voltage for activation to less depolarized voltages. Moreover, we show that the E267A proton glutamate mutant conserves transport currents, albeit reduced. Lastly, the positive shift in activation voltage shown by V580M, a mutant identified in a patient with late- onset lysosomal storage disease, can explain loss-of-function leading to disease. Abstract figure legend CLC transport proteins comprise both channels and transporters. Vesicular CLC transporters function to regulate compartmental ionic homeostasis and acidification. ClC-6 is a vesicular CLC that localizes to the endo-lysosomal compartment. Functional plasma membrane overexpression of GFP-tagged ClC-6 in HEK293 cells surmounted spatial inaccessibility, and rapid whole cell patch recording protocols enabling resolution of fast capacitive transients, as well as ionic transport currents, provided details of wild-type ClC-6 biophysical properties including voltage-dependence, pH-dependence, and kinetics. Clearly defined wild-type ClC-6 function permitted subsequent comparative analysis of mutants, including but not limited to those pertinent to disease. These range from one causing severe, early-onset neurodegeneration, to two variants previously identified in Kufs disease, a late-onset lysosomal storage disease characterized by neuronal ceroid lipofuscinosis. These findings further inform models whereby disruption of ClC-6 biophysical properties set the stage for dysregulated compartmental homeostasis and hence, disease. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Giovanni Zifarelli
- Institute of Biophysics, CNR, Genoa, Italy.,Present address: Centogene GmbH, Rostock, Germany
| | | | - Peying Fong
- Department of Anatomy and Physiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA
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21
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Current Methods to Unravel the Functional Properties of Lysosomal Ion Channels and Transporters. Cells 2022; 11:cells11060921. [PMID: 35326372 PMCID: PMC8946281 DOI: 10.3390/cells11060921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/04/2022] [Accepted: 03/05/2022] [Indexed: 02/07/2023] Open
Abstract
A distinct set of channels and transporters regulates the ion fluxes across the lysosomal membrane. Malfunctioning of these transport proteins and the resulting ionic imbalance is involved in various human diseases, such as lysosomal storage disorders, cancer, as well as metabolic and neurodegenerative diseases. As a consequence, these proteins have stimulated strong interest for their suitability as possible drug targets. A detailed functional characterization of many lysosomal channels and transporters is lacking, mainly due to technical difficulties in applying the standard patch-clamp technique to these small intracellular compartments. In this review, we focus on current methods used to unravel the functional properties of lysosomal ion channels and transporters, stressing their advantages and disadvantages and evaluating their fields of applicability.
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22
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Baxter LL, Watkins-Chow DE, Johnson NL, Farhat NY, Platt FM, Dale RK, Porter FD, Pavan WJ, Rodriguez-Gil JL. Correlation of age of onset and clinical severity in Niemann-Pick disease type C1 with lysosomal abnormalities and gene expression. Sci Rep 2022; 12:2162. [PMID: 35140266 PMCID: PMC8828765 DOI: 10.1038/s41598-022-06112-y] [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: 10/26/2021] [Accepted: 01/18/2022] [Indexed: 11/08/2022] Open
Abstract
Niemann-Pick disease type C1 (NPC1) is a rare, prematurely fatal lysosomal storage disorder which exhibits highly variable severity and disease progression as well as a wide-ranging age of onset, from perinatal stages to adulthood. This heterogeneity has made it difficult to obtain prompt diagnosis and to predict disease course. In addition, small NPC1 patient sample sizes have been a limiting factor in acquiring genome-wide transcriptome data. In this study, primary fibroblasts from an extensive cohort of 41 NPC1 patients were used to validate our previous findings that the lysosomal quantitative probe LysoTracker can be used as a predictor for age of onset and disease severity. We also examined the correlation between these clinical parameters and RNA expression data from primary fibroblasts and identified a set of genes that were significantly associated with lysosomal defects or age of onset, in particular neurological symptom onset. Hierarchical clustering showed that these genes exhibited distinct expression patterns among patient subgroups. This study is the first to collect transcriptomic data on such a large scale in correlation with clinical and cellular phenotypes, providing a rich genomic resource to address NPC1 clinical heterogeneity and discover potential biomarkers, disease modifiers, or therapeutic targets.
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Affiliation(s)
- Laura L Baxter
- Genomics, Development and Disease Section, Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Dawn E Watkins-Chow
- Genomics, Development and Disease Section, Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nicholas L Johnson
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Nicole Y Farhat
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Ryan K Dale
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Forbes D Porter
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - William J Pavan
- Genomics, Development and Disease Section, Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Jorge L Rodriguez-Gil
- Genomics, Development and Disease Section, Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
- Division of Medical Genetics, Stanford University School of Medicine, Stanford, CA, USA.
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.
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23
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The Role of the Lysosomal Cl−/H+ Antiporter ClC-7 in Osteopetrosis and Neurodegeneration. Cells 2022; 11:cells11030366. [PMID: 35159175 PMCID: PMC8833911 DOI: 10.3390/cells11030366] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/16/2022] [Accepted: 01/19/2022] [Indexed: 12/04/2022] Open
Abstract
CLC proteins comprise Cl− channels and anion/H+ antiporters involved in several fundamental physiological processes. ClC-7 is a lysosomal Cl−/H+ antiporter that together with its beta subunit Ostm1 has a critical role in the ionic homeostasis of lysosomes and of the osteoclasts’ resorption lacuna, although the specific underlying mechanism has so far remained elusive. Mutations in ClC-7 cause osteopetrosis, but also a form of lysosomal storage disease and neurodegeneration. Interestingly, both loss-of- and gain-of-function mutations of ClC-7 can be pathogenic, but the mechanistic implications of this finding are still unclear. This review will focus on the recent advances in our understanding of the biophysical properties of ClC-7 and of its role in human diseases with a focus on osteopetrosis and neurodegeneration.
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Gardner E, Mole SE. The Genetic Basis of Phenotypic Heterogeneity in the Neuronal Ceroid Lipofuscinoses. Front Neurol 2021; 12:754045. [PMID: 34733232 PMCID: PMC8558747 DOI: 10.3389/fneur.2021.754045] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/20/2021] [Indexed: 12/12/2022] Open
Abstract
The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited neurodegenerative disorders that affect children and adults. They share some similar clinical features and the accumulation of autofluorescent storage material. Since the discovery of the first causative genes, more than 530 mutations have been identified across 13 genes in cases diagnosed with NCL. These genes encode a variety of proteins whose functions have not been fully defined; most are lysosomal enzymes, or transmembrane proteins of the lysosome or other organelles. Many mutations in these genes are associated with a typical NCL disease phenotype. However, increasing numbers of variant disease phenotypes are being described, affecting age of onset, severity or progression, and including some distinct clinical phenotypes. This data is collated by the NCL Mutation Database which allows analysis from many perspectives. This article will summarise and interpret current knowledge and understanding of their genetic basis and phenotypic heterogeneity.
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Affiliation(s)
- Emily Gardner
- MRC Laboratory for Molecular Cell Biology and Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Sara E Mole
- MRC Laboratory for Molecular Cell Biology and Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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Duncan AR, Polovitskaya MM, Gaitán-Peñas H, Bertelli S, VanNoy GE, Grant PE, O’Donnell-Luria A, Valivullah Z, Lovgren AK, England EM, Agolini E, Madden JA, Schmitz-Abe K, Kritzer A, Hawley P, Novelli A, Alfieri P, Colafati GS, Wieczorek D, Platzer K, Luppe J, Koch-Hogrebe M, Abou Jamra R, Neira-Fresneda J, Lehman A, Boerkoel CF, Seath K, Clarke L, van Ierland Y, Argilli E, Sherr EH, Maiorana A, Diel T, Hempel M, Bierhals T, Estévez R, Jentsch TJ, Pusch M, Agrawal PB, Agrawal PB. Unique variants in CLCN3, encoding an endosomal anion/proton exchanger, underlie a spectrum of neurodevelopmental disorders. Am J Hum Genet 2021; 108:1450-1465. [PMID: 34186028 DOI: 10.1016/j.ajhg.2021.06.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/02/2021] [Indexed: 12/24/2022] Open
Abstract
The genetic causes of global developmental delay (GDD) and intellectual disability (ID) are diverse and include variants in numerous ion channels and transporters. Loss-of-function variants in all five endosomal/lysosomal members of the CLC family of Cl- channels and Cl-/H+ exchangers lead to pathology in mice, humans, or both. We have identified nine variants in CLCN3, the gene encoding CIC-3, in 11 individuals with GDD/ID and neurodevelopmental disorders of varying severity. In addition to a homozygous frameshift variant in two siblings, we identified eight different heterozygous de novo missense variants. All have GDD/ID, mood or behavioral disorders, and dysmorphic features; 9/11 have structural brain abnormalities; and 6/11 have seizures. The homozygous variants are predicted to cause loss of ClC-3 function, resulting in severe neurological disease similar to the phenotype observed in Clcn3-/- mice. Their MRIs show possible neurodegeneration with thin corpora callosa and decreased white matter volumes. Individuals with heterozygous variants had a range of neurodevelopmental anomalies including agenesis of the corpus callosum, pons hypoplasia, and increased gyral folding. To characterize the altered function of the exchanger, electrophysiological analyses were performed in Xenopus oocytes and mammalian cells. Two variants, p.Ile607Thr and p.Thr570Ile, had increased currents at negative cytoplasmic voltages and loss of inhibition by luminal acidic pH. In contrast, two other variants showed no significant difference in the current properties. Overall, our work establishes a role for CLCN3 in human neurodevelopment and shows that both homozygous loss of ClC-3 and heterozygous variants can lead to GDD/ID and neuroanatomical abnormalities.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Pankaj B Agrawal
- Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Division of Genetics & Genomics, Department of Pediatrics, Boston Children's Hospital, MA 02115, USA.
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Ritter M, Bresgen N, Kerschbaum HH. From Pinocytosis to Methuosis-Fluid Consumption as a Risk Factor for Cell Death. Front Cell Dev Biol 2021; 9:651982. [PMID: 34249909 PMCID: PMC8261248 DOI: 10.3389/fcell.2021.651982] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/29/2021] [Indexed: 12/11/2022] Open
Abstract
The volumes of a cell [cell volume (CV)] and its organelles are adjusted by osmoregulatory processes. During pinocytosis, extracellular fluid volume equivalent to its CV is incorporated within an hour and membrane area equivalent to the cell's surface within 30 min. Since neither fluid uptake nor membrane consumption leads to swelling or shrinkage, cells must be equipped with potent volume regulatory mechanisms. Normally, cells respond to outwardly or inwardly directed osmotic gradients by a volume decrease and increase, respectively, i.e., they shrink or swell but then try to recover their CV. However, when a cell death (CD) pathway is triggered, CV persistently decreases in isotonic conditions in apoptosis and it increases in necrosis. One type of CD associated with cell swelling is due to a dysfunctional pinocytosis. Methuosis, a non-apoptotic CD phenotype, occurs when cells accumulate too much fluid by macropinocytosis. In contrast to functional pinocytosis, in methuosis, macropinosomes neither recycle nor fuse with lysosomes but with each other to form giant vacuoles, which finally cause rupture of the plasma membrane (PM). Understanding methuosis longs for the understanding of the ionic mechanisms of cell volume regulation (CVR) and vesicular volume regulation (VVR). In nascent macropinosomes, ion channels and transporters are derived from the PM. Along trafficking from the PM to the perinuclear area, the equipment of channels and transporters of the vesicle membrane changes by retrieval, addition, and recycling from and back to the PM, causing profound changes in vesicular ion concentrations, acidification, and-most importantly-shrinkage of the macropinosome, which is indispensable for its proper targeting and cargo processing. In this review, we discuss ion and water transport mechanisms with respect to CVR and VVR and with special emphasis on pinocytosis and methuosis. We describe various aspects of the complex mutual interplay between extracellular and intracellular ions and ion gradients, the PM and vesicular membrane, phosphoinositides, monomeric G proteins and their targets, as well as the submembranous cytoskeleton. Our aim is to highlight important cellular mechanisms, components, and processes that may lead to methuotic CD upon their derangement.
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Affiliation(s)
- Markus Ritter
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria
- Institute for Physiology and Pathophysiology, Paracelsus Medical University, Nuremberg, Germany
- Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
- Ludwig Boltzmann Institute for Arthritis und Rehabilitation, Salzburg, Austria
- Kathmandu University School of Medical Sciences, Dhulikhel, Nepal
| | - Nikolaus Bresgen
- Department of Biosciences, University of Salzburg, Salzburg, Austria
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He H, Guzman RE, Cao D, Sierra-Marquez J, Yin F, Fahlke C, Peng J, Stauber T. The molecular and phenotypic spectrum of CLCN4-related epilepsy. Epilepsia 2021; 62:1401-1415. [PMID: 33951195 DOI: 10.1111/epi.16906] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/01/2021] [Accepted: 04/01/2021] [Indexed: 01/02/2023]
Abstract
OBJECTIVE This study was undertaken to expand the phenotypic and genetic spectrum of CLCN4-related epilepsy and to investigate genotype-phenotype correlations. METHODS We systematically reviewed the phenotypic and genetic spectrum of newly diagnosed and previously reported patients with CLCN4-related epilepsy. Three novel variants identified in four patients reported in this study were evaluated through in silico prediction and functional analysis by Western blot, immunofluorescence, and electrophysiological measurements. RESULTS Epilepsy was diagnosed in 54.55% (24/44) of individuals with CLCN4-related disorders and was drug-resistant in most cases. Of 24 patients, 15 had epileptic encephalopathy and four died at an early age; 69.57% of patients had seizure onset within the first year of life. Myoclonic seizures are the most common seizure type, and 56.25% of patients presented multiple seizure types. Notably, seizure outcome was favorable in individuals with only one seizure type. All patients showed intellectual disability, which was severe in 65.22% of patients. Additional common features included language delay, behavioral disorders, and dysmorphic features. Five patients benefitted from treatment with lamotrigine. Most variants, which were mainly missense (79.17%), were inherited (70.83%). Whereas frameshift, intragenic deletion, or inherited variants were associated with milder phenotypes, missense or de novo variants led to more severe phenotypes. All evaluated CLCN4 variants resulted in loss of function with reduced ClC-4 currents. Nonetheless, genotype-phenotype relationships for CLCN4-related epilepsy are not straightforward, as phenotypic variability was observed in recurrent variants and within single families. SIGNIFICANCE Pathogenic CLCN4 variants contribute significantly to the genetic etiology of epilepsy. The phenotypic spectrum of CLCN4-related epilepsy includes drug-resistant seizures, cognitive and language impairment, behavioral disorders, and congenital anomalies. Notably, the mutation type and the number of seizure types correlate with the severity of the phenotype, suggesting its use for clinical prognosis. Lamotrigine can be considered a therapeutic option.
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Affiliation(s)
- Hailan He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Raul E Guzman
- Institute of Biological Information Processing (IBI-1), Molecular and Cell Physiology, Jülich Research Center, Jülich, Germany
| | - Dezhi Cao
- Neurology Department, Shenzhen Children's Hospital, Shenzhen, China
| | - Juan Sierra-Marquez
- Institute of Biological Information Processing (IBI-1), Molecular and Cell Physiology, Jülich Research Center, Jülich, Germany
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Christoph Fahlke
- Institute of Biological Information Processing (IBI-1), Molecular and Cell Physiology, Jülich Research Center, Jülich, Germany
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Tobias Stauber
- Institute of Chemistry and Biochemistry, Berlin Free University, Berlin, Germany.,Department of Human Medicine and Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
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Bose S, He H, Stauber T. Neurodegeneration Upon Dysfunction of Endosomal/Lysosomal CLC Chloride Transporters. Front Cell Dev Biol 2021; 9:639231. [PMID: 33708769 PMCID: PMC7940362 DOI: 10.3389/fcell.2021.639231] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/03/2021] [Indexed: 12/15/2022] Open
Abstract
The regulation of luminal ion concentrations is critical for the function of, and transport between intracellular organelles. The importance of the acidic pH in the compartments of the endosomal-lysosomal pathway has been well-known for decades. Besides the V-ATPase, which pumps protons into their lumen, a variety of ion transporters and channels is involved in the regulation of the organelles' complex ion homeostasis. Amongst these are the intracellular members of the CLC family, ClC-3 through ClC-7. They localize to distinct but overlapping compartments of the endosomal-lysosomal pathway, partially with tissue-specific expression. Functioning as 2Cl−/H+ exchangers, they can support the vesicular acidification and accumulate luminal Cl−. Mutations in the encoding genes in patients and mouse models underlie severe phenotypes including kidney stones with CLCN5 and osteopetrosis or hypopigmentation with CLCN7. Dysfunction of those intracellular CLCs that are expressed in neurons lead to neuronal defects. Loss of endosomal ClC-3, which heteromerizes with ClC-4, results in neurodegeneration. Mutations in ClC-4 are associated with epileptic encephalopathy and intellectual disability. Mice lacking the late endosomal ClC-6 develop a lysosomal storage disease with reduced pain sensitivity. Human gene variants have been associated with epilepsy, and a gain-of-function mutation causes early-onset neurodegeneration. Dysfunction of the lysosomal ClC-7 leads to a lysosomal storage disease and neurodegeneration in mice and humans. Reduced luminal chloride, as well as altered calcium regulation, has been associated with lysosomal storage diseases in general. This review discusses the properties of endosomal and lysosomal Cl−/H+ exchange by CLCs and how various alterations of ion transport by CLCs impact organellar ion homeostasis and function in neurodegenerative disorders.
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Affiliation(s)
- Shroddha Bose
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Hailan He
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.,Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Tobias Stauber
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.,Department of Human Medicine and Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
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