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Jiang J, Ren R, Fang W, Miao J, Wen Z, Wang X, Xu J, Jin H. Lysosomal biogenesis and function in osteoclasts: a comprehensive review. Front Cell Dev Biol 2024; 12:1431566. [PMID: 39170917 PMCID: PMC11335558 DOI: 10.3389/fcell.2024.1431566] [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: 05/12/2024] [Accepted: 07/19/2024] [Indexed: 08/23/2024] Open
Abstract
Lysosomes serve as catabolic centers and signaling hubs in cells, regulating a multitude of cellular processes such as intracellular environment homeostasis, macromolecule degradation, intracellular vesicle trafficking and autophagy. Alterations in lysosomal level and function are crucial for cellular adaptation to external stimuli, with lysosome dysfunction being implicated in the pathogenesis of numerous diseases. Osteoclasts (OCs), as multinucleated cells responsible for bone resorption and maintaining bone homeostasis, have a complex relationship with lysosomes that is not fully understood. Dysregulated function of OCs can disrupt bone homeostasis leading to the development of various bone disorders. The regulation of OC differentiation and bone resorption for the treatment of bone disease have received considerable attention in recent years, yet the role and regulation of lysosomes in OCs, as well as the potential therapeutic implications of intervening in lysosomal biologic behavior for the treatment of bone diseases, remain relatively understudied. This review aims to elucidate the mechanisms involved in lysosomal biogenesis and to discuss the functions of lysosomes in OCs, specifically in relation to differentiation, bone resorption, and autophagy. Finally, we explore the potential therapeutic implication of targeting lysosomes in the treatment of bone metabolic disorders.
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Affiliation(s)
- Junchen Jiang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Rufeng Ren
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Weiyuan Fang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Jiansen Miao
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Zijun Wen
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Xiangyang Wang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Jiake Xu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Haiming Jin
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
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2
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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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3
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Nanoparticle-Mediated Therapeutic Application for Modulation of Lysosomal Ion Channels and Functions. Pharmaceutics 2020; 12:pharmaceutics12030217. [PMID: 32131531 PMCID: PMC7150957 DOI: 10.3390/pharmaceutics12030217] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 02/07/2023] Open
Abstract
Applications of nanoparticles in various fields have been addressed. Nanomaterials serve as carriers for transporting conventional drugs or proteins through lysosomes to various cellular targets. The basic function of lysosomes is to trigger degradation of proteins and lipids. Understanding of lysosomal functions is essential for enhancing the efficacy of nanoparticles-mediated therapy and reducing the malfunctions of cellular metabolism. The lysosomal function is modulated by the movement of ions through various ion channels. Thus, in this review, we have focused on the recruited ion channels for lysosomal function, to understand the lysosomal modulation through the nanoparticles and its applications. In the future, lysosomal channels-based targets will expand the therapeutic application of nanoparticles-associated drugs.
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Lee JH, Wolfe DM, Darji S, McBrayer MK, Colacurcio DJ, Kumar A, Stavrides P, Mohan PS, Nixon RA. β2-adrenergic Agonists Rescue Lysosome Acidification and Function in PSEN1 Deficiency by Reversing Defective ER-to-lysosome Delivery of ClC-7. J Mol Biol 2020; 432:2633-2650. [PMID: 32105735 DOI: 10.1016/j.jmb.2020.02.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/11/2020] [Accepted: 02/12/2020] [Indexed: 02/06/2023]
Abstract
Lysosomal dysfunction is considered pathogenic in Alzheimer disease (AD). Loss of presenilin-1 (PSEN1) function causing AD impedes acidification via defective vacuolar ATPase (vATPase) V0a1 subunit delivery to lysosomes. We report that isoproterenol (ISO) and related β2-adrenergic agonists reacidify lysosomes in PSEN1 Knock out (KO) cells and fibroblasts from PSEN1 familial AD patients, which restores lysosomal proteolysis, calcium homeostasis, and normal autophagy flux. We identify a novel rescue mechanism involving Portein Kinase A (PKA)-mediated facilitation of chloride channel-7 (ClC-7) delivery to lysosomes which reverses markedly lowered chloride (Cl-) content in PSEN1 KO lysosomes. Notably, PSEN1 loss of function impedes Endoplasmic Reticulum (ER)-to-lysosome delivery of ClC-7. Transcriptomics of PSEN1-deficient cells reveals strongly downregulated ER-to-lysosome transport pathways and reversibility by ISO, thus accounting for lysosomal Cl- deficits that compound pH elevation due to deficient vATPase and its rescue by β2-adrenergic agonists. Our findings uncover a broadened PSEN1 role in lysosomal ion homeostasis and novel pH modulation of lysosomes through β2-adrenergic regulation of ClC-7, which can potentially be modulated therapeutically.
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Affiliation(s)
- Ju-Hyun Lee
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA; Department of Psychiatry, Langone Medical Center, New York, NY, 10016, USA.
| | - Devin M Wolfe
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA
| | - Sandipkumar Darji
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA
| | - Mary Kate McBrayer
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA
| | - Daniel J Colacurcio
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA
| | - Asok Kumar
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA
| | - Philip Stavrides
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA
| | - Panaiyur S Mohan
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA; Department of Psychiatry, Langone Medical Center, New York, NY, 10016, USA
| | - Ralph A Nixon
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA; Department of Psychiatry, Langone Medical Center, New York, NY, 10016, USA; Department of Cell Biology, Langone Medical Center, New York, NY, 10016, USA; Neuroscience Institute, New York University, New York, NY 10016, USA.
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5
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Jung YK, Kwon KT, Jang JA, Han MS, Kim GW, Han S. Enhanced Activation of Rac1/Cdc42 and MITF Leads to Augmented Osteoclastogenesis in Autosomal Dominant Osteopetrosis Type II. JBMR Plus 2018; 3:e10070. [PMID: 30828687 PMCID: PMC6383696 DOI: 10.1002/jbm4.10070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 05/28/2018] [Accepted: 06/10/2018] [Indexed: 11/23/2022] Open
Abstract
The autosomal dominant osteopetrosis type II (ADOII) caused by the mutation of chloride channel 7 (ClC‐7) gene is the most common form of adult‐onset osteopetrosis. Despite dysfunctional bone resorption, an augmented osteoclast differentiation was reported recently in ADOII patients. DNA sequencing analysis of the ADOII patient's ClC‐7 gene identified a known heterozygous mutation, c.643G>A in exon 7, encoding p.Gly215Arg. In vitro osteoclast differentiation from the ADOII patient's peripheral blood mononuclear cells (PBMCs) increased compared with control despite their dysfunctional bone resorbing capacity. Osteoclasts from the ADOII patient's PBMCs and ClC‐7 knockdown bone marrow monocytes (BMMs) showed an enhanced Ser‐71 phosphorylation of Rac1/Cdc42 and increase of the microphthalmia‐associated transcription factor (MITF) and receptor activator of NF‐κB (RANK) that can be responsible for the enhanced osteoclast differentiation. © 2018 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
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Affiliation(s)
- Youn-Kwan Jung
- Laboratory for Arthritis and Bone Biology Fatima Research Institute Daegu Fatima Hospital Daegu Republic of Korea
| | - Ki-Tae Kwon
- Department of Internal Medicine Kyungpook National University Hospital Daegu Republic of Korea
| | - Ji-Ae Jang
- Laboratory for Arthritis and Bone Biology Fatima Research Institute Daegu Fatima Hospital Daegu Republic of Korea
| | - Min-Su Han
- Laboratory for Arthritis and Bone Biology Fatima Research Institute Daegu Fatima Hospital Daegu Republic of Korea
| | - Gun-Woo Kim
- Laboratory for Arthritis and Bone Biology Fatima Research Institute Daegu Fatima Hospital Daegu Republic of Korea.,Department of Internal Medicine Daegu Fatima Hospital Daegu Republic of Korea
| | - Seungwoo Han
- Laboratory for Arthritis and Bone Biology Fatima Research Institute Daegu Fatima Hospital Daegu Republic of Korea.,Department of Internal Medicine Kyungpook National University Hospital Daegu Republic of Korea
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6
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Li BY, Gao YH, Pei JR, Yang YM, Zhang W, Sun DJ. ClC-7/Ostm1 contribute to the ability of tea polyphenols to maintain bone homeostasis in C57BL/6 mice, protecting against fluorosis. Int J Mol Med 2017; 39:1155-1163. [PMID: 28339032 PMCID: PMC5403613 DOI: 10.3892/ijmm.2017.2933] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 02/21/2017] [Indexed: 01/09/2023] Open
Abstract
Epidemiological investigations indicate that certain ingredients in tea bricks can antagonize the adverse effects of fluoride. Tea polyphenols (TPs), the most bioactive ingredient in tea bricks, have been demonstrated to be potent bone-supporting agents. ClC‑7 is known to be crucial for osteoclast (OC) bone resorption. Thus, in this study, we investigated the potential protective effects of TPs against fluorosis using a mouse model and explored the underlying mechanisms with particular focus on ClC‑7. A total of 40, healthy, 3‑week‑old male C57BL/6 mice were randomly divided into 4 groups (n=10/group) by weight as follows: distilled water (control group), 100 mg/l fluoridated water (F group), water containing 10 g/l TPs (TP group) and water containing 100 mg/l fluoride and 10 g/l TPs (F + TP group). After 15 weeks, and after the mice were sacrificed, the long bones were removed and bone marrow-derived macrophages were cultured ex vivo in order to perform several experiments. OCs were identified and counted by tartrate‑resistant acid phosphatase (TRAP) staining. The consumption of fluoride resulted in severe fluorosis and in an impaired OC function [impaired bone resorption, and a low mRNA expression of nuclear factor of activated T-cells 1 (NFATc1), ATPase H+ transporting V0 subunit D2 (ATP6v0d2) and osteopetrosis‑associated transmembrane protein 1 (Ostm1)]. In the F + TP group, fluorosis was attenuated and OC function was restored, but not the high bone fluoride content. Compared with the F group, mature OCs in the F + TP group expressed higher mRNA levels of ClC‑7 and Ostm1; the transportation and retaining of Cl‑ was improved, as shown by the fluorescence intensity experiment. On the whole, our findings indicate that TPs mitigate fluorosis in C57BL/6 mice by regulating OC bone resorption. Fluoride inhibits OC resorption by inhibiting ClC‑7 and Ostm1, whereas TPs attenuate this inhibitory effect of fluoride.
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Affiliation(s)
- Bing-Yun Li
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Yan-Hui Gao
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Jun-Rui Pei
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Yan-Mei Yang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Wei Zhang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Dian-Jun Sun
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
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7
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Imbrici P, Liantonio A, Camerino GM, De Bellis M, Camerino C, Mele A, Giustino A, Pierno S, De Luca A, Tricarico D, Desaphy JF, Conte D. Therapeutic Approaches to Genetic Ion Channelopathies and Perspectives in Drug Discovery. Front Pharmacol 2016; 7:121. [PMID: 27242528 PMCID: PMC4861771 DOI: 10.3389/fphar.2016.00121] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 04/25/2016] [Indexed: 12/21/2022] Open
Abstract
In the human genome more than 400 genes encode ion channels, which are transmembrane proteins mediating ion fluxes across membranes. Being expressed in all cell types, they are involved in almost all physiological processes, including sense perception, neurotransmission, muscle contraction, secretion, immune response, cell proliferation, and differentiation. Due to the widespread tissue distribution of ion channels and their physiological functions, mutations in genes encoding ion channel subunits, or their interacting proteins, are responsible for inherited ion channelopathies. These diseases can range from common to very rare disorders and their severity can be mild, disabling, or life-threatening. In spite of this, ion channels are the primary target of only about 5% of the marketed drugs suggesting their potential in drug discovery. The current review summarizes the therapeutic management of the principal ion channelopathies of central and peripheral nervous system, heart, kidney, bone, skeletal muscle and pancreas, resulting from mutations in calcium, sodium, potassium, and chloride ion channels. For most channelopathies the therapy is mainly empirical and symptomatic, often limited by lack of efficacy and tolerability for a significant number of patients. Other channelopathies can exploit ion channel targeted drugs, such as marketed sodium channel blockers. Developing new and more specific therapeutic approaches is therefore required. To this aim, a major advancement in the pharmacotherapy of channelopathies has been the discovery that ion channel mutations lead to change in biophysics that can in turn specifically modify the sensitivity to drugs: this opens the way to a pharmacogenetics strategy, allowing the development of a personalized therapy with increased efficacy and reduced side effects. In addition, the identification of disease modifiers in ion channelopathies appears an alternative strategy to discover novel druggable targets.
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Affiliation(s)
- Paola Imbrici
- 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
| | - Giulia M Camerino
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Michela De Bellis
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Claudia Camerino
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro" Bari, Italy
| | - Antonietta Mele
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Arcangela Giustino
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro" Bari, Italy
| | - Sabata Pierno
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Annamaria De Luca
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Domenico Tricarico
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Jean-Francois Desaphy
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro" Bari, Italy
| | - Diana Conte
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
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8
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Khantwal CM, Abraham SJ, Han W, Jiang T, Chavan TS, Cheng RC, Elvington SM, Liu CW, Mathews II, Stein RA, Mchaourab HS, Tajkhorshid E, Maduke M. Revealing an outward-facing open conformational state in a CLC Cl(-)/H(+) exchange transporter. eLife 2016; 5. [PMID: 26799336 PMCID: PMC4769167 DOI: 10.7554/elife.11189] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/14/2016] [Indexed: 11/22/2022] Open
Abstract
CLC secondary active transporters exchange Cl- for H+. Crystal structures have suggested that the conformational change from occluded to outward-facing states is unusually simple, involving only the rotation of a conserved glutamate (Gluex) upon its protonation. Using 19F NMR, we show that as [H+] is increased to protonate Gluex and enrich the outward-facing state, a residue ~20 Å away from Gluex, near the subunit interface, moves from buried to solvent-exposed. Consistent with functional relevance of this motion, constriction via inter-subunit cross-linking reduces transport. Molecular dynamics simulations indicate that the cross-link dampens extracellular gate-opening motions. In support of this model, mutations that decrease steric contact between Helix N (part of the extracellular gate) and Helix P (at the subunit interface) remove the inhibitory effect of the cross-link. Together, these results demonstrate the formation of a previously uncharacterized 'outward-facing open' state, and highlight the relevance of global structural changes in CLC function. DOI:http://dx.doi.org/10.7554/eLife.11189.001 Cells have transporter proteins on their surface to carry molecules in and out of the cell. For example, the CLC family of transporters move two chloride ions in one direction at the same time as moving one hydrogen ion in the opposite direction. To be able to move these ions in opposite directions, transporters have to cycle through a series of shapes in which the ions can only access alternate sides of the membrane. First, the transporter adopts an 'outward-facing' shape when the ions first bind to the transporter, then it switches into the 'occluded' shape to move the ions through the membrane. Finally, the transporter takes on the 'inward-facing' shape to release the ions on the other side of the membrane. However, structural studies of CLCs suggest that the structures of these proteins do not change much while they are moving ions, which suggests that they might work in a different way. Khantwal, Abraham et al. have now used techniques called “nuclear magnetic resonance” and "double electron-electron resonance" to investigate how a CLC from a bacterium moves ions. The experiments suggest that when the transporter adopts the outward-facing shape, points on the protein known as Y419 and D417 shift their positions. Chemically linking two regions of the CLC prevented this movement and inhibited the transport of chloride ions across the membrane. Khantwal, Abraham et al. then used a computer simulation to model how the protein changes shape in more detail. This model predicts that two regions of the transporter undergo major rearrangements resulting in a gate-opening motion that widens a passage to allow the chloride ions to bind to the protein. Khantwal, Abraham et al.’s findings will prompt future studies to reveal the other shapes and how CLCs transition between them. DOI:http://dx.doi.org/10.7554/eLife.11189.002
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Affiliation(s)
- Chandra M Khantwal
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Sherwin J Abraham
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Wei Han
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, United States.,College of Medicine, University of Illinois at Urbana-Champaign, Urbana, United States.,Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Tao Jiang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, United States.,College of Medicine, University of Illinois at Urbana-Champaign, Urbana, United States.,Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Tanmay S Chavan
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Ricky C Cheng
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Shelley M Elvington
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
| | - Corey W Liu
- Stanford Magnetic Resonance Laboratory, Stanford University School of Medicine, Stanford, United States
| | - Irimpan I Mathews
- Stanford Synchrotron Radiation Lightsource, Stanford University, Menlo Park, United States
| | - Richard A Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States
| | - Hassane S Mchaourab
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States
| | - Emad Tajkhorshid
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, United States.,College of Medicine, University of Illinois at Urbana-Champaign, Urbana, United States.,Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Merritt Maduke
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, United States
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9
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Chen M, Qiao H, Su Z, Li H, Ping Q, Zong L. Emerging therapeutic targets for osteoporosis treatment. Expert Opin Ther Targets 2014; 18:817-31. [PMID: 24766518 DOI: 10.1517/14728222.2014.912632] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION To date, osteoporosis still remains a major public health burden especially for the aging populations. Over the last few decades treatments for osteoporosis have largely focused on anti-resorptive agents represented by bisphosphonates and estrogen therapy that dominated the market. Unsatisfactory efficacy, non-specificity and long-term safety of current therapies necessitate the need for new targets effectively preventing and treating of osteoporosis. AREAS COVERED This review expatiates on the mechanism of osteoporosis occurrence and bone remodeling cycle in detail. New targets of antiresorptive and anabolic agents based on the functions of osteoblasts and osteoclasts as well as associated signaling pathways are outlined. EXPERT OPINION Advanced understanding in the fields of bone remodeling, functions of osteoblasts, osteoclasts and osteocytes associated with osteoporosis occurrence offers the emerging bone-resorptive or bone-formative targets. Currently, molecules involving RANK-RANKL-OPG system and Wnt/β-catenin signaling pathway act as the most promising targets.
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Affiliation(s)
- Minglei Chen
- China Pharmaceutical University, Key Lab of State Natural Medicine, Department of Pharmaceutics , Nanjing 210009 , PR China +86 25 83271092; +86 25 83271317 ; +86 25 83271092; +86 25 83271317 ; ;
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10
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Abstract
The lack of small-molecule inhibitors for anion-selective transporters and channels has impeded our understanding of the complex mechanisms that underlie ion passage. The ubiquitous CLC "Chloride Channel" family represents a unique target for biophysical and biochemical studies because its distinctive protein fold supports both passive chloride channels and secondary-active chloride-proton transporters. Here, we describe the synthesis and characterization of a specific small-molecule inhibitor directed against a CLC antiporter (ClC-ec1). This compound, 4,4'-octanamidostilbene-2,2'-disulfonate (OADS), inhibits ClC-ec1 with low micromolar affinity and has no specific effect on a CLC channel (ClC-1). Inhibition of ClC-ec1 occurs by binding to two distinct intracellular sites. The location of these sites and the lipid dependence of inhibition suggest potential mechanisms of action. This compound will empower research to elucidate differences between antiporter and channel mechanisms and to develop treatments for CLC-mediated disorders.
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11
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A novel missense mutation in the CLCN7 gene linked to benign autosomal dominant osteopetrosis: a case series. J Med Case Rep 2013; 7:7. [PMID: 23302420 PMCID: PMC3567968 DOI: 10.1186/1752-1947-7-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Accepted: 11/13/2012] [Indexed: 12/21/2022] Open
Abstract
Introduction Osteopetrosis is a rare inherited genetic disease characterized by sclerosis of the skeleton. The absence or malfunction of osteoclasts is found to be strongly associated with the disease evolution. Currently, four clinically distinct forms of the disease have been recognized: the infantile autosomal recessive osteopetrosis, the malignant and the intermediate forms, and autosomal dominant osteopetrosis, type I and type II forms. The autosomal recessive types are the most severe forms with symptoms in very early childhood, whereas the autosomal dominant classes exhibit a heterogeneous trait with milder symptoms, often at later childhood or adulthood. Case presentation Case 1 is the 12-year-old daughter (index patient) of an Iraqi-Kurdish family who, at the age of eight years, was diagnosed clinically to have mild autosomal dominant osteopetrosis. Presently, at 12-years old, she has severe complications due to the disease progression. In addition, the same family previously experienced the death of a female child in her late childhood. The deceased child had been misdiagnosed, at that time, with thalassemia major. In this report, we extended our investigation to identify the type of the inheritance patterns of osteopetrosis using molecular techniques, because consanguineous marriages exist within the family history. We have detected one heterozygous mutation in exon 15 of the Chloride Channel 7 gene in the index patient (Case 1), whereas other mutations were not detected in the associated genes TCIRG1, OSTM1, RANK, and RANKL. The missense mutation (CGG>TGG) located in exon 15 (c.1225C>T) of the Chloride Channel 7 gene changed the amino acid position 409 from arginine to tryptophan (p.R409W, c.1225C>T). Case 2 is the 16-year-old son (brother of the index patient) of the same family who was diagnosed clinically with mild autosomal dominant osteopetrosis. We have identified the same heterozygous mutation in exon 15 of the Chloride channel 7 gene in this patient (Case 2). The missense mutation (CGG>TGG) located in exon 15 (c.1225C>T) of the Chloride channel 7 gene changed the amino acid position 409 from arginine to tryptophan (p.R409W, c.1225C>T). In addition to the clinical diagnosis of both cases, the missense mutation we identified in one allele of the Chloride channel 7 gene could be linked to autosomal dominant osteopetrosis-II because the symptoms appear in late childhood or adolescence. Conclusion In this family, the molecular diagnosis was confirmed after identification of the same mutation in the older son (sibling). Furthermore, we detected that the father and his brother (the uncle) are carriers of the same mutation, whereas the mother and her sister (the aunt) do not carry any mutation of the Chloride channel 7 gene. Thus, the disease penetrance is at least 60% in the family. The mother and father are cousins and a further consanguineous marriage between the aunt and the uncle is not recommended because the dominant allele of the Chloride channel 7 gene will be transferred to the progeny. However, a similar risk is also expected following a marriage between the uncle and an unrelated woman. The p.R409W mutation in the Chloride channel 7 gene has not yet been described in the literature and it possibly has a dominant-negative impact on the protein.
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Khoontawad J, Laothong U, Roytrakul S, Pinlaor P, Mulvenna J, Wongkham C, Yongvanit P, Pairojkul C, Mairiang E, Sithithaworn P, Pinlaor S. Proteomic identification of plasma protein tyrosine phosphatase alpha and fibronectin associated with liver fluke, Opisthorchis viverrini, infection. PLoS One 2012; 7:e45460. [PMID: 23029023 PMCID: PMC3445495 DOI: 10.1371/journal.pone.0045460] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/22/2012] [Indexed: 12/02/2022] Open
Abstract
Opisthorchiasis caused by Opisthorchis viverrini induces periductal fibrosis via host immune/inflammatory responses. Plasma protein alteration during host-parasite interaction-mediated inflammation may provide potential diagnostic and/or prognostic biomarkers. To search for target protein changes in O. viverrini-infected hamsters, a 1-D PAGE gel band was trypsin-digested and analyzed by a LC-MS/MS-based proteomics approach in the plasma profile of infected hamsters, and applied to humans. Sixty seven proteins were selected for further analysis based on at least two unique tryptic peptides with protein ID score >10 and increased expression at least two times across time points. These proteins have not been previously identified in O. viverrini-associated infection. Among those, proteins involved in structural (19%), immune response (13%), cell cycle (10%) and transcription (10%) were highly expressed. Western blots revealed an expression level of protein tyrosine phosphatase alpha (PTPα) which reached a peak at 1 month and subsequently tended to decrease. Fibronectin significantly increased at 1 month and tended to increase with time, supporting proteomic analysis. PTPα was expressed in the cytoplasm of inflammatory cells, while fibronectin was observed mainly in the cytoplasm of fibroblasts and the extracellular matrix at periductal fibrosis areas. In addition, these protein levels significantly increased in the plasma of O. viverrini-infected patients compared to healthy individuals, and significantly decreased at 2-months post-treatment, indicating their potential as disease markers. In conclusion, our results suggest that plasma PTPα and fibronectin may be associated with opisthorchiasis and the hamster model provides the basis for development of novel diagnostic markers in the future.
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Affiliation(s)
- Jarinya Khoontawad
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Umawadee Laothong
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Sittiruk Roytrakul
- Proteomics Research Laboratory, Genome Institute Biotechnology, Pathumthani, Thailand
| | - Porntip Pinlaor
- Centre for Research and Development in Medical Diagnostic Laboratory, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Jason Mulvenna
- Department of Infectious Disease and Cancer, Faculty of Computational Biology, Queensland Institute of Medical Research, Brisbane, Queensland, Australia
| | - Chaisiri Wongkham
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Puangrat Yongvanit
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Chawalit Pairojkul
- Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Eimorn Mairiang
- Department of Radiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Paiboon Sithithaworn
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Somchai Pinlaor
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- * E-mail:
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Xue Y, Wang W, Mao T, Duan X. Report of two Chinese patients suffering from CLCN7-related osteopetrosis and root dysplasia. J Craniomaxillofac Surg 2011; 40:416-20. [PMID: 21962762 DOI: 10.1016/j.jcms.2011.07.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2011] [Revised: 07/27/2011] [Accepted: 07/30/2011] [Indexed: 12/15/2022] Open
Abstract
Osteopetrosis is a group of genetic bone disorders. There are three types of osteopetrosis: autosomal recessive osteopetrosis (ARO), autosomal dominant osteopetrosis type II (ADO II), and intermediate autosomal recessive osteopetrosis (IARO). The prevalence of ADO II is about 1:100,000, while no more than 20 cases of IARO have been reported worldwide. We present the first Chinese IARO patient with a novel homozygous variant in CLCN7 gene (p. Pro470Leu) and an ADO II patient with a heterozygous variant in CLCN7 gene (p. Arg286Trp). In addition to general osteosclerosis, the striking features of these two patients are unerupted teeth with root dysplasia. We speculate that ClC-7 in different tooth cells may contribute directly to the root development, the defect of ClC-7 may have a dose dependent effect on the phenotype of root dysplasia, and the tooth position may also affect the root phenotype with dysfunctional ClC-7.
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Affiliation(s)
- Yang Xue
- Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, Xi'an, Shaanxi 710032, PR China
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Antibodies against ClC7 inhibit extracellular acidification-induced Cl− currents and bone resorption activity in mouse osteoclasts. Naunyn Schmiedebergs Arch Pharmacol 2010; 383:79-90. [DOI: 10.1007/s00210-010-0576-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 10/24/2010] [Indexed: 01/20/2023]
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Schulz P, Werner J, Stauber T, Henriksen K, Fendler K. The G215R mutation in the Cl-/H+-antiporter ClC-7 found in ADO II osteopetrosis does not abolish function but causes a severe trafficking defect. PLoS One 2010; 5:e12585. [PMID: 20830208 PMCID: PMC2935355 DOI: 10.1371/journal.pone.0012585] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 08/15/2010] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND ClC-7 is a ubiquitous transporter which is broadly expressed in mammalian tissues. It is implied in the pathogenesis of lysosomal storage disease and osteopetrosis. Because of its endosomal/lysosomal localization it is still poorly characterized. METHODOLOGY/PRINCIPAL FINDINGS An electrophysiological characterization of rat ClC-7 using solid-supported membrane-based electrophysiology is presented. The measured currents show the characteristics of ClC-7 and confirm its function as a Cl(-)/H(+)-antiporter. We have used rat ClC-7 in CHO cells as a model system to investigate the functionality and cellular localization of the wt transporter and its variant G213R ClC-7 which is the analogue of human G215R ClC-7 responsible for autosomal dominant osteopetrosis type II. Our study shows that rat G213R ClC-7 is functional but has a localization defect in CHO cells which prevents it from being correctly targeted to the lysosomal membrane. The electrophysiological assay is tested as a tool for drug discovery. The assay is validated with a number of drug candidates. It is shown that ClC-7 is inhibited by DIDS, NPPB and NS5818 at micromolar concentrations. CONCLUSIONS/SIGNIFICANCE It is suggested that the scenario found in the CHO model system also applies to the human transporter and that mislocalization rather than impaired functionality of G215R ClC-7 is the primary cause of the related autosomal dominant osteopetrosis type II. Furthermore, the robust solid-supported membrane-based electrophysiological assay is proposed for rapid screening for potential ClC-7 inhibitors which are discussed for treatment of osteoporosis.
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Affiliation(s)
- Patrick Schulz
- Department of Biophysical Chemistry, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Johannes Werner
- Department of Biophysical Chemistry, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Tobias Stauber
- Leibniz-Institut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | | | - Klaus Fendler
- Department of Biophysical Chemistry, Max Planck Institute of Biophysics, Frankfurt, Germany
- * E-mail:
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