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Zeng W, Li C, Wu R, Yang X, Wang Q, Lin B, Wei Y, Li H, Shan G, Qu L, Cang C. Optogenetic manipulation of lysosomal physiology and autophagy-dependent clearance of amyloid beta. PLoS Biol 2024; 22:e3002591. [PMID: 38652732 DOI: 10.1371/journal.pbio.3002591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 03/17/2024] [Indexed: 04/25/2024] Open
Abstract
Lysosomes are degradation centers of cells and intracellular hubs of signal transduction, nutrient sensing, and autophagy regulation. Dysfunction of lysosomes contributes to a variety of diseases, such as lysosomal storage diseases (LSDs) and neurodegeneration, but the mechanisms are not well understood. Altering lysosomal activity and examining its impact on the occurrence and development of disease is an important strategy for studying lysosome-related diseases. However, methods to dynamically regulate lysosomal function in living cells or animals are still lacking. Here, we constructed lysosome-localized optogenetic actuators, named lyso-NpHR3.0, lyso-ArchT, and lyso-ChR2, to achieve optogenetic manipulation of lysosomes. These new actuators enable light-dependent control of lysosomal membrane potential, pH, hydrolase activity, degradation, and Ca2+ dynamics in living cells. Notably, lyso-ChR2 activation induces autophagy through the mTOR pathway, promotes Aβ clearance in an autophagy-dependent manner in cellular models, and alleviates Aβ-induced paralysis in the Caenorhabditis elegans model of Alzheimer's disease. Our lysosomal optogenetic actuators supplement the optogenetic toolbox and provide a method to dynamically regulate lysosomal physiology and function in living cells and animals.
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Affiliation(s)
- Wenping Zeng
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Canjun Li
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Institute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei, Anhui, China
| | - Ruikun Wu
- Department of Laboratory Medicine, The First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Xingguo Yang
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Qingyan Wang
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Bingqian Lin
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Yanan Wei
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Hao Li
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Ge Shan
- Department of Laboratory Medicine, The First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Lili Qu
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Chunlei Cang
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Institute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei, Anhui, China
- The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Neurodegenerative Disorder Research Center, University of Science and Technology of China, Hefei, Anhui, China
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2
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Castillo-Velasquez C, Matamala E, Becerra D, Orio P, Brauchi SE. Optical recordings of organellar membrane potentials and the components of membrane conductance in lysosomes. J Physiol 2024; 602:1637-1654. [PMID: 38625711 DOI: 10.1113/jp283825] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 03/20/2024] [Indexed: 04/17/2024] Open
Abstract
The eukaryotic cell is highly compartmentalized with organelles. Owing to their function in transporting metabolites, metabolic intermediates and byproducts of metabolic activity, organelles are important players in the orchestration of cellular function. Recent advances in optical methods for interrogating the different aspects of organellar activity promise to revolutionize our ability to dissect cellular processes with unprecedented detail. The transport activity of organelles is usually coupled to the transport of charged species; therefore, it is not only associated with the metabolic landscape but also entangled with membrane potentials. In this context, the targeted expression of fluorescent probes for interrogating organellar membrane potential (Ψorg) emerges as a powerful approach, offering less-invasive conditions and technical simplicity to interrogate cellular signalling and metabolism. Different research groups have made remarkable progress in adapting a variety of optical methods for measuring and monitoring Ψorg. These approaches include using potentiometric dyes, genetically encoded voltage indicators, hybrid fluorescence resonance energy transfer sensors and photoinduced electron transfer systems. These studies have provided consistent values for the resting potential of single-membrane organelles, such as lysosomes, the Golgi and the endoplasmic reticulum. We can foresee the use of dynamic measurements of Ψorg to study fundamental problems in organellar physiology that are linked to serious cellular disorders. Here, we present an overview of the available techniques, a survey of the resting membrane potential of internal membranes and, finally, an open-source mathematical model useful to interpret and interrogate membrane-bound structures of small volume by using the lysosome as an example.
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Affiliation(s)
- Cristian Castillo-Velasquez
- Department of Physiology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Valdivia, Chile
| | - Ella Matamala
- Department of Physiology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Valdivia, Chile
| | - Diego Becerra
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Instituto de Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Sebastian E Brauchi
- Department of Physiology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Valdivia, Chile
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3
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Braulke T, Carette JE, Palm W. Lysosomal enzyme trafficking: from molecular mechanisms to human diseases. Trends Cell Biol 2024; 34:198-210. [PMID: 37474375 DOI: 10.1016/j.tcb.2023.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/16/2023] [Accepted: 06/19/2023] [Indexed: 07/22/2023]
Abstract
Lysosomes degrade and recycle macromolecules that are delivered through the biosynthetic, endocytic, and autophagic routes. Hydrolysis of the different classes of macromolecules is catalyzed by about 70 soluble enzymes that are transported from the Golgi apparatus to lysosomes in a mannose 6-phosphate (M6P)-dependent process. The molecular machinery that generates M6P tags for receptor-mediated targeting of lysosomal enzymes was thought to be understood in detail. However, recent studies on the M6P pathway have identified a previously uncharacterized core component, yielded structural insights in known components, and uncovered functions in various human diseases. Here we review molecular mechanisms of lysosomal enzyme trafficking and discuss its relevance for rare lysosomal disorders, cancer, and viral infection.
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Affiliation(s)
- Thomas Braulke
- Department of Osteology and Biomechanics, Cell Biology of Rare Diseases, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Wilhelm Palm
- German Cancer Research Center (DKFZ), Heidelberg, Germany.
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4
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Li K, Guo Y, Wang Y, Zhu R, Chen W, Cheng T, Zhang X, Jia Y, Liu T, Zhang W, Jan LY, Jan YN. Drosophila TMEM63 and mouse TMEM63A are lysosomal mechanosensory ion channels. Nat Cell Biol 2024; 26:393-403. [PMID: 38388853 PMCID: PMC10940159 DOI: 10.1038/s41556-024-01353-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 01/10/2024] [Indexed: 02/24/2024]
Abstract
Cells sense physical forces and convert them into electrical or chemical signals, a process known as mechanotransduction. Whereas extensive studies focus on mechanotransduction at the plasma membrane, little is known about whether and how intracellular organelles sense mechanical force and the physiological functions of organellar mechanosensing. Here we identify the Drosophila TMEM63 (DmTMEM63) ion channel as an intrinsic mechanosensor of the lysosome, a major degradative organelle. Endogenous DmTMEM63 proteins localize to lysosomes, mediate lysosomal mechanosensitivity and modulate lysosomal morphology and function. Tmem63 mutant flies exhibit impaired lysosomal degradation, synaptic loss, progressive motor deficits and early death, with some of these mutant phenotypes recapitulating symptoms of TMEM63-associated human diseases. Importantly, mouse TMEM63A mediates lysosomal mechanosensitivity in Neuro-2a cells, indicative of functional conservation in mammals. Our findings reveal DmTMEM63 channel function in lysosomes and its physiological roles in vivo and provide a molecular basis to explore the mechanosensitive process in subcellular organelles.
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Affiliation(s)
- Kai Li
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Yanmeng Guo
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Yayu Wang
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Ruijun Zhu
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Wei Chen
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Tong Cheng
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Xiaofan Zhang
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Yinjun Jia
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
| | - Ting Liu
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
| | - Wei Zhang
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
| | - Lily Yeh Jan
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Yuh Nung Jan
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA.
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5
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Riederer E, Ren D. Lysosomal channels sensing forces. Nat Cell Biol 2024; 26:318-320. [PMID: 38388852 DOI: 10.1038/s41556-024-01347-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Affiliation(s)
- Erika Riederer
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
| | - Dejian Ren
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
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6
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Iyer H, Talbot WS. The Cl- transporter ClC-7 is essential for phagocytic clearance by microglia. J Cell Sci 2024; 137:jcs261616. [PMID: 38294065 PMCID: PMC10911276 DOI: 10.1242/jcs.261616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 01/15/2024] [Indexed: 02/01/2024] Open
Abstract
Microglia, professional phagocytic cells of the brain, rely upon the appropriate activation of lysosomes to execute their immune and clearance functions. Lysosomal activity is, in turn, modulated by a complex network of over 200 membrane and accessory proteins that relay extracellular cues to these key degradation centers. The ClC-7 chloride (Cl-)-proton (H+) antiporter (also known as CLCN7) is localized to the endolysosomal compartments and mutations in CLCN7 lead to osteopetrosis and neurodegeneration. Although the functions of ClC-7 have been extensively investigated in osteoclasts and neurons, its role in microglia in vivo remains largely unexamined. Here, we show that microglia and embryonic macrophages in zebrafish clcn7 mutants cannot effectively process extracellular debris in the form of apoptotic cells and β-amyloid. Despite these functional defects, microglia develop normally in clcn7 mutants and display normal expression of endosomal and lysosomal markers. We also find that mutants for ostm1, which encodes the β-subunit of ClC-7, have a phenotype that is strikingly similar to that of clcn7 mutants. Together, our observations uncover a previously unappreciated role of ClC-7 in microglia and contribute to the understanding of the neurodegenerative phenotypes that accompany mutations in this channel.
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Affiliation(s)
- Harini Iyer
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - William S. Talbot
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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7
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Gao J, Li H, Lv H, Cheng X. Mutation of TRPML1 Channel and Pathogenesis of Neurodegeneration in Haimeria. Mol Neurobiol 2023:10.1007/s12035-023-03874-y. [PMID: 38157120 DOI: 10.1007/s12035-023-03874-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/11/2023] [Indexed: 01/03/2024]
Abstract
Neurodegenerative diseases, a group of debilitating disorders, have garnered increasing attention due to their escalating prevalence, particularly among aging populations. Alzheimer's disease (AD) reigns as a prominent exemplar within this category, distinguished by its relentless progression of cognitive impairment and the accumulation of aberrant protein aggregates within the intricate landscape of the brain. While the intricate pathogenesis of neurodegenerative diseases has been the subject of extensive investigation, recent scientific inquiry has unveiled a novel player in this complex scenario-transient receptor potential mucolipin 1 (TRPML1) channels. This comprehensive review embarks on an exploration of the intricate interplay between TRPML1 channels and neurodegenerative diseases, with an explicit spotlight on Alzheimer's disease. It immerses itself in the intricate molecular mechanisms governing TRPML1 channel functionality and elucidates their profound implications for the well-being of neurons. Furthermore, the review ventures into the realm of therapeutic potential, pondering the possibilities and challenges associated with targeting TRPML1 channels as a promising avenue for the amelioration of neurodegenerative disorders. As we traverse this multifaceted terrain of neurodegeneration and the enigmatic role of TRPML1 channels, we embark on a journey that not only broadens our understanding of the intricate machinery governing neuronal health but also holds promise for the development of innovative therapeutic interventions in the relentless battle against neurodegenerative diseases.
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Affiliation(s)
- Junqing Gao
- Department of Neurology, Shaanxi Provincial People's Hospital, Shaanxi, Xi'an, 710068, China
| | - Huanhuan Li
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Shaanxi, Xi'an, 710038, China
| | - Hua Lv
- Department of Neurology, Shaanxi Provincial People's Hospital, Shaanxi, Xi'an, 710068, China
| | - Xiansong Cheng
- Department of Neurology, Shaanxi Provincial People's Hospital, Shaanxi, Xi'an, 710068, China.
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8
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Wu L, Lin Y, Song J, Li L, Rao X, Wan W, Wei G, Hua F, Ying J. TMEM175: A lysosomal ion channel associated with neurological diseases. Neurobiol Dis 2023; 185:106244. [PMID: 37524211 DOI: 10.1016/j.nbd.2023.106244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/09/2023] [Accepted: 07/28/2023] [Indexed: 08/02/2023] Open
Abstract
Lysosomes are acidic intracellular organelles with autophagic functions that are critical for protein degradation and mitochondrial homeostasis, while abnormalities in lysosomal physiological functions are closely associated with neurological disorders. Transmembrane protein 175 (TMEM175), an ion channel in the lysosomal membrane that is essential for maintaining lysosomal acidity, has been proven to coordinate with V-ATPase to modulate the luminal pH of the lysosome to assist the digestion of abnormal proteins and organelles. However, there is considerable controversy about the characteristics of TMEM175. In this review, we introduce the research progress on the structural, modulatory, and functional properties of TMEM175, followed by evidence of its relevance for neurological disorders. Finally, we discuss the potential value of TMEM175 as a therapeutic target in the hope of providing new directions for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Luojia Wu
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China; Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006 Nanchang City, Jiangxi Privince, China
| | - Yue Lin
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China; Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006 Nanchang City, Jiangxi Privince, China
| | - Jiali Song
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China; Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006 Nanchang City, Jiangxi Privince, China
| | - Longshan Li
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China; Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006 Nanchang City, Jiangxi Privince, China
| | - Xiuqin Rao
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China; Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006 Nanchang City, Jiangxi Privince, China
| | - Wei Wan
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China; Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006 Nanchang City, Jiangxi Privince, China
| | - Gen Wei
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China; Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006 Nanchang City, Jiangxi Privince, China
| | - Fuzhou Hua
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China; Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006 Nanchang City, Jiangxi Privince, China.
| | - Jun Ying
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China; Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006 Nanchang City, Jiangxi Privince, China.
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Bazzone A, Barthmes M, George C, Brinkwirth N, Zerlotti R, Prinz V, Cole K, Friis S, Dickson A, Rice S, Lim J, Fern Toh M, Mohammadi M, Pau D, Stone DJ, Renger JJ, Fertig N. A Comparative Study on the Lysosomal Cation Channel TMEM175 Using Automated Whole-Cell Patch-Clamp, Lysosomal Patch-Clamp, and Solid Supported Membrane-Based Electrophysiology: Functional Characterization and High-Throughput Screening Assay Development. Int J Mol Sci 2023; 24:12788. [PMID: 37628970 PMCID: PMC10454728 DOI: 10.3390/ijms241612788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/09/2023] [Accepted: 08/12/2023] [Indexed: 08/27/2023] Open
Abstract
The lysosomal cation channel TMEM175 is a Parkinson's disease-related protein and a promising drug target. Unlike whole-cell automated patch-clamp (APC), lysosomal patch-clamp (LPC) facilitates physiological conditions, but is not yet suitable for high-throughput screening (HTS) applications. Here, we apply solid supported membrane-based electrophysiology (SSME), which enables both direct access to lysosomes and high-throughput electrophysiological recordings. In SSME, ion translocation mediated by TMEM175 is stimulated using a concentration gradient at a resting potential of 0 mV. The concentration-dependent K+ response exhibited an I/c curve with two distinct slopes, indicating the existence of two conducting states. We measured H+ fluxes with a permeability ratio of PH/PK = 48,500, which matches literature findings from patch-clamp studies, validating the SSME approach. Additionally, TMEM175 displayed a high pH dependence. Decreasing cytosolic pH inhibited both K+ and H+ conductivity of TMEM175. Conversely, lysosomal pH and pH gradients did not have major effects on TMEM175. Finally, we developed HTS assays for drug screening and evaluated tool compounds (4-AP, Zn as inhibitors; DCPIB, arachidonic acid, SC-79 as enhancers) using SSME and APC. Additionally, we recorded EC50 data for eight blinded TMEM175 enhancers and compared the results across all three assay technologies, including LPC, discussing their advantages and disadvantages.
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Affiliation(s)
- Andre Bazzone
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Maria Barthmes
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Cecilia George
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Nina Brinkwirth
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Rocco Zerlotti
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
- RIGeL-Regensburg International Graduate School of Life Sciences, University of Regensburg, 93053 Regensburg, Germany
| | - Valentin Prinz
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Kim Cole
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Søren Friis
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Alexander Dickson
- SB Drug Discovery, West of Scotland Science Park, Glasgow G20 0XA, UK; (A.D.); (S.R.)
| | - Simon Rice
- SB Drug Discovery, West of Scotland Science Park, Glasgow G20 0XA, UK; (A.D.); (S.R.)
| | - Jongwon Lim
- Cerevel Therapeutics, 222 Jacobs St, Cambridge, MA 02141, USA; (J.L.); (M.F.T.); (D.J.S.); (J.J.R.)
| | - May Fern Toh
- Cerevel Therapeutics, 222 Jacobs St, Cambridge, MA 02141, USA; (J.L.); (M.F.T.); (D.J.S.); (J.J.R.)
| | | | - Davide Pau
- SB Drug Discovery, West of Scotland Science Park, Glasgow G20 0XA, UK; (A.D.); (S.R.)
| | - David J. Stone
- Cerevel Therapeutics, 222 Jacobs St, Cambridge, MA 02141, USA; (J.L.); (M.F.T.); (D.J.S.); (J.J.R.)
| | - John J. Renger
- Cerevel Therapeutics, 222 Jacobs St, Cambridge, MA 02141, USA; (J.L.); (M.F.T.); (D.J.S.); (J.J.R.)
| | - Niels Fertig
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
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10
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Tang T, Jian B, Liu Z. Transmembrane Protein 175, a Lysosomal Ion Channel Related to Parkinson's Disease. Biomolecules 2023; 13:biom13050802. [PMID: 37238672 DOI: 10.3390/biom13050802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/14/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
Lysosomes are membrane-bound organelles with an acidic lumen and are traditionally characterized as a recycling center in cells. Lysosomal ion channels are integral membrane proteins that form pores in lysosomal membranes and allow the influx and efflux of essential ions. Transmembrane protein 175 (TMEM175) is a unique lysosomal potassium channel that shares little sequence similarity with other potassium channels. It is found in bacteria, archaea, and animals. The prokaryotic TMEM175 consists of one six-transmembrane domain that adopts a tetrameric architecture, while the mammalian TMEM175 is comprised of two six-transmembrane domains that function as a dimer in lysosomal membranes. Previous studies have demonstrated that the lysosomal K+ conductance mediated by TMEM175 is critical for setting membrane potential, maintaining pH stability, and regulating lysosome-autophagosome fusion. AKT and B-cell lymphoma 2 regulate TMEM175's channel activity through direct binding. Two recent studies reported that the human TMEM175 is also a proton-selective channel under normal lysosomal pH (4.5-5.5) as the K+ permeation dramatically decreased at low pH while the H+ current through TMEM175 greatly increased. Genome-wide association studies and functional studies in mouse models have established that TMEM175 is implicated in the pathogenesis of Parkinson's disease, which sparks more research interests in this lysosomal channel.
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Affiliation(s)
- Tuoxian Tang
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Boshuo Jian
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Zhenjiang Liu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
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Rahman MA, Rahman MS, Parvez MAK, Kim B. The Emerging Role of Autophagy as a Target of Environmental Pollutants: An Update on Mechanisms. Toxics 2023; 11:toxics11020135. [PMID: 36851010 PMCID: PMC9965655 DOI: 10.3390/toxics11020135] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/09/2023] [Accepted: 01/28/2023] [Indexed: 06/09/2023]
Abstract
Autophagy is an evolutionarily conserved cellular system crucial for cellular homeostasis that protects cells from a broad range of internal and extracellular stresses. Autophagy decreases metabolic load and toxicity by removing damaged cellular components. Environmental contaminants, particularly industrial substances, can influence autophagic flux by enhancing it as a protective response, preventing it, or converting its protective function into a pro-cell death mechanism. Environmental toxic materials are also notorious for their tendency to bioaccumulate and induce pathophysiological vulnerability. Many environmental pollutants have been found to influence stress which increases autophagy. Increasing autophagy was recently shown to improve stress resistance and reduce genetic damage. Moreover, suppressing autophagy or depleting its resources either increases or decreases toxicity, depending on the circumstances. The essential process of selective autophagy is utilized by mammalian cells in order to eliminate particulate matter, nanoparticles, toxic metals, and smoke exposure without inflicting damage on cytosolic components. Moreover, cigarette smoke and aging are the chief causes of chronic obstructive pulmonary disease (COPD)-emphysema; however, the disease's molecular mechanism is poorly known. Therefore, understanding the impacts of environmental exposure via autophagy offers new approaches for risk assessment, protection, and preventative actions which will counter the harmful effects of environmental contaminants on human and animal health.
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Affiliation(s)
- Md. Ataur Rahman
- Department of Pathology, College of Korean Medicine, Kyung Hee University, 1-5 Hoegidong Dongdaemun-gu, Seoul 02447, Republic of Korea
- Korean Medicine-Based Drug Repositioning Cancer Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Md Saidur Rahman
- Department of Animal Science & Technology and BET Research Institute, Chung-Ang University, Anseong 17546, Republic of Korea
| | | | - Bonglee Kim
- Department of Pathology, College of Korean Medicine, Kyung Hee University, 1-5 Hoegidong Dongdaemun-gu, Seoul 02447, Republic of Korea
- Korean Medicine-Based Drug Repositioning Cancer Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
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Blaschke TF, Insel PA, Amara SG, Meyer UA. Introduction to the Theme "Development of New Drugs: Moving from the Bench to Bedside and Improved Patient Care". Annu Rev Pharmacol Toxicol 2023; 63:15-18. [PMID: 36270297 DOI: 10.1146/annurev-pharmtox-091222-022612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Investigations in pharmacology and toxicology range from molecular studies to clinical care. Studies in basic and clinical pharmacology and in preclinical and clinical toxicology are all essential in bringing new knowledge and new drugs into clinical use. The 30 reviews in Volume 63 of the Annual Review of Pharmacology and Toxicology explore topics across this spectrum. Examples include "Zebrafish as a Mainstream Model for In Vivo Systems Pharmacology and Toxicology" and "Artificial Intelligence and Machine Learning for Lead-to-Candidate Decision-Making and Beyond." Other reviews discuss components important for drug discovery and development and the use of pharmaceuticals in a variety of diseases. Air pollution continues to increase globally; accordingly, "Air Pollution-Related Neurotoxicity Across the Life Span" is a timely and forward-thinking review. Volume 63 also explores the use of contemporary technologies such as electronic health records, pharmacogenetics, and new drug delivery systems that help enhance and improve the utility of new therapies.
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Affiliation(s)
| | - Paul A Insel
- Departments of Pharmacology and Medicine, University of California, San Diego, La Jolla, California, USA
| | - Susan G Amara
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
| | - Urs A Meyer
- Biozentrum, University of Basel, Basel, Switzerland
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Chen CC. Electrophysiological Techniques on the Study of Endolysosomal Ion Channels. Handb Exp Pharmacol 2023; 278:217-233. [PMID: 36871125 DOI: 10.1007/164_2023_638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Endolysosomal ion channels are a group of ion channel proteins that are functionally expressed on the membrane of endolysosomal vesicles. The electrophysiological properties of these ion channels in the intracellular organelle membrane cannot be observed using conventional electrophysiological techniques. This section compiles the different electrophysiological techniques utilized in recent years to study endolysosomal ion channels and describes their methodological characteristics, emphasizing the most widely used technique for whole endolysosome recordings to date. This includes the use of different pharmacological tools and genetic tools for the application of patch-clamping techniques for specific stages of endolysosomes, allowing the recording of ion channel activity in different organelles, such as recycling endosomes, early endosomes, late endosomes, and lysosomes. These electrophysiological techniques are not only cutting-edge technologies that help to investigate the biophysical properties of known and unknown intracellular ion channels but also help us to investigate the physiopathological role of these ion channels in the distribution of dynamic vesicles and to identify new therapeutic targets for precision medicine and drug screening.
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Affiliation(s)
- Cheng-Chang Chen
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan.
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
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