1
|
Kim H, Choi S, Lee E, Koh W, Lee CJ. Tonic NMDA Receptor Currents in the Brain: Regulation and Cognitive Functions. Biol Psychiatry 2024; 96:164-175. [PMID: 38490367 DOI: 10.1016/j.biopsych.2024.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 02/20/2024] [Accepted: 03/04/2024] [Indexed: 03/17/2024]
Abstract
Synaptically localized NMDA receptors (NMDARs) play a crucial role in important cognitive functions by mediating synaptic transmission and plasticity. In contrast, a tonic NMDAR current, thought to be mediated by extrasynaptic NMDARs, has a less clear function. This review provides a comprehensive overview of tonic NMDAR currents, focusing on their roles in synaptic transmission/plasticity and their impact on cognitive functions and psychiatric disorders. We discuss the roles of 3 endogenous ligands (i.e., glutamate, glycine, and D-serine) and receptors in mediating tonic NMDAR currents and explore the diverse mechanisms that regulate tonic NMDAR currents. In light of recent controversies surrounding the source of D-serine, we highlight the recent findings suggesting that astrocytes release D-serine to modulate tonic NMDAR currents and control cognitive flexibility. Furthermore, we propose distinct roles of neuronal and astrocytic D-serine in different locations and their implications for synaptic regulation and cognitive functions. The potential roles of tonic NMDAR currents in various psychiatric disorders, such as schizophrenia and autism spectrum disorder, are discussed in the context of the NMDAR hypofunction hypothesis. By presenting the mechanisms by which various cells, particularly astrocytes, regulate tonic NMDAR currents, we aim to stimulate future research in NMDAR hypofunction- or hyperfunction-related psychiatric disorders. This review not only provides a better understanding of the complex interplay between tonic NMDAR currents and cognitive functions but also sheds light on its potential therapeutic target for the treatment of various psychiatric disorders.
Collapse
Affiliation(s)
- Hayoung Kim
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science, Daejeon, South Korea
| | - Sunyeong Choi
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science, Daejeon, South Korea
| | - Euisun Lee
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science, Daejeon, South Korea
| | - Wuhyun Koh
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science, Daejeon, South Korea.
| | - C Justin Lee
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science, Daejeon, South Korea.
| |
Collapse
|
2
|
Knecht DA, Zeziulia M, Bhavsar MB, Puchkov D, Maier H, Jentsch TJ. LRRC8/VRAC volume-regulated anion channels are crucial for hearing. J Biol Chem 2024; 300:107436. [PMID: 38838775 PMCID: PMC11260850 DOI: 10.1016/j.jbc.2024.107436] [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: 01/22/2024] [Revised: 05/09/2024] [Accepted: 05/23/2024] [Indexed: 06/07/2024] Open
Abstract
Hearing crucially depends on cochlear ion homeostasis as evident from deafness elicited by mutations in various genes encoding cation or anion channels and transporters. Ablation of ClC‑K/barttin chloride channels causes deafness by interfering with the positive electrical potential of the endolymph, but roles of other anion channels in the inner ear have not been studied. Here we report the intracochlear distribution of all five LRRC8 subunits of VRAC, a volume-regulated anion channel that transports chloride, metabolites, and drugs such as the ototoxic anti-cancer drug cisplatin, and explore its physiological role by ablating its subunits. Sensory hair cells express all LRRC8 isoforms, whereas only LRRC8A, D and E were found in the potassium-secreting epithelium of the stria vascularis. Cochlear disruption of the essential LRRC8A subunit, or combined ablation of LRRC8D and E, resulted in cochlear degeneration and congenital deafness of Lrrc8a-/- mice. It was associated with a progressive degeneration of the organ of Corti and its innervating spiral ganglion. Like disruption of ClC-K/barttin, loss of VRAC severely reduced the endocochlear potential. However, the mechanism underlying this reduction seems different. Disruption of VRAC, but not ClC-K/barttin, led to an almost complete loss of Kir4.1 (KCNJ10), a strial K+ channel crucial for the generation of the endocochlear potential. The strong downregulation of Kir4.1 might be secondary to a loss of VRAC-mediated transport of metabolites regulating inner ear redox potential such as glutathione. Our study extends the knowledge of the role of cochlear ion transport in hearing and ototoxicity.
Collapse
Affiliation(s)
- Deborah A Knecht
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | - Mariia Zeziulia
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany; Graduate Program of the Freie Universität Berlin, Berlin, Germany
| | - Mit B Bhavsar
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
| | - Dmytro Puchkov
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Hannes Maier
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany; Cluster of Excellence "Hearing4all", Hannover, Germany
| | - Thomas J Jentsch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany.
| |
Collapse
|
3
|
Carpanese V, Festa M, Prosdocimi E, Bachmann M, Sadeghi S, Bertelli S, Stein F, Velle A, Abdel-Salam MAL, Romualdi C, Pusch M, Checchetto V. Interactomic exploration of LRRC8A in volume-regulated anion channels. Cell Death Discov 2024; 10:299. [PMID: 38909013 PMCID: PMC11193767 DOI: 10.1038/s41420-024-02032-0] [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: 11/27/2023] [Revised: 05/08/2024] [Accepted: 05/16/2024] [Indexed: 06/24/2024] Open
Abstract
Ion channels are critical in enabling ion movement into and within cells and are important targets for pharmacological interventions in different human diseases. In addition to their ion transport abilities, ion channels interact with signalling and scaffolding proteins, which affects their function, cellular positioning, and links to intracellular signalling pathways. The study of "channelosomes" within cells has the potential to uncover their involvement in human diseases, although this field of research is still emerging. LRRC8A is the gene that encodes a crucial protein involved in the formation of volume-regulated anion channels (VRACs). Some studies suggest that LRRC8A could be a valuable prognostic tool in different types of cancer, serving as a biomarker for predicting patients' outcomes. LRRC8A expression levels might be linked to tumour progression, metastasis, and treatment response, although its implications in different cancer types can be varied. Here, publicly accessible databases of cancer patients were systematically analysed to determine if a correlation between VRAC channel expression and survival rate exists across distinct cancer types. Moreover, we re-evaluated the impact of LRRC8A on cellular proliferation and migration in colon cancer via HCT116 LRRC8A-KO cells, which is a current topic of debate in the literature. In addition, to investigate the role of LRRC8A in cellular signalling, we conducted biotin proximity-dependent identification (BioID) analysis, revealing a correlation between VRAC channels and cell-cell junctions, mechanisms that govern cellular calcium homeostasis, kinases, and GTPase signalling. Overall, this dataset improves our understanding of LRRC8A/VRAC and explores new research avenues while identifying promising therapeutic targets and promoting inventive methods for disease treatment.
Collapse
Affiliation(s)
| | - Margherita Festa
- DiBio, Unipd, via Ugo Bassi 58/B, 35131, Padova, Italy
- Institute of Biophysics, CNR, Via De Marini, 6 16149, Genova, Italy
| | | | - Magdalena Bachmann
- DiBio, Unipd, via Ugo Bassi 58/B, 35131, Padova, Italy
- Daba Farber Cancer Research Institute, Boston, MA, USA
| | - Soha Sadeghi
- DiBio, Unipd, via Ugo Bassi 58/B, 35131, Padova, Italy
| | - Sara Bertelli
- Institute of Biophysics, CNR, Via De Marini, 6, 16149, Genova, Italy
- Humboldt Universität Berlin, AG Zelluläre Biophysik, Dorotheenstr, 19-21 10099, Berlin, Germany
| | - Frank Stein
- Proteomics Core Facility, EMBL Heidelberg, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Angelo Velle
- DiBio, Unipd, via Ugo Bassi 58/B, 35131, Padova, Italy
| | - Mostafa A L Abdel-Salam
- DiBio, Unipd, via Ugo Bassi 58/B, 35131, Padova, Italy
- UPMC Hillman Cancer Center, Pittsburgh, PA, USA
| | - Chiara Romualdi
- DiBio, Unipd, via Ugo Bassi 58/B, 35131, Padova, Italy
- Padua Center for Network Medicine, University of Padua, Via F. Marzolo 8, 315126, Padova, Italy
| | - Michael Pusch
- Institute of Biophysics, CNR, Via De Marini, 6, 16149, Genova, Italy
- RAISE Ecosystem, Genova, Italy
| | | |
Collapse
|
4
|
Okada Y. Physiology of the volume-sensitive/regulatory anion channel VSOR/VRAC: part 2: its activation mechanisms and essential roles in organic signal release. J Physiol Sci 2024; 74:34. [PMID: 38877402 PMCID: PMC11177392 DOI: 10.1186/s12576-024-00926-3] [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: 05/05/2024] [Accepted: 06/01/2024] [Indexed: 06/16/2024]
Abstract
The volume-sensitive outwardly rectifying or volume-regulated anion channel, VSOR/VRAC, which was discovered in 1988, is expressed in most vertebrate cell types, and is essentially involved in cell volume regulation after swelling and in the induction of cell death. This series of review articles describes what is already known and what remains to be uncovered about the functional and molecular properties as well as the physiological and pathophysiological roles of VSOR/VRAC. This Part 2 review article describes, from the physiological and pathophysiological standpoints, first the pivotal roles of VSOR/VRAC in the release of autocrine/paracrine organic signal molecules, such as glutamate, ATP, glutathione, cGAMP, and itaconate, as well as second the swelling-independent and -dependent activation mechanisms of VSOR/VRAC. Since the pore size of VSOR/VRAC has now well been evaluated by electrophysiological and 3D-structural methods, the signal-releasing activity of VSOR/VRAC is here discussed by comparing the molecular sizes of these organic signals to the channel pore size. Swelling-independent activation mechanisms include a physicochemical one caused by the reduction of intracellular ionic strength and a biochemical one caused by oxidation due to stimulation by receptor agonists or apoptosis inducers. Because some organic substances released via VSOR/VRAC upon cell swelling can trigger or augment VSOR/VRAC activation in an autocrine fashion, swelling-dependent activation mechanisms are to be divided into two phases: the first phase induced by cell swelling per se and the second phase caused by receptor stimulation by released organic signals.
Collapse
Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences (NIPS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
- Department of Integrative Physiology, Graduate School of Medicine, Akita University, Akita, Japan.
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, Japan.
- Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan.
| |
Collapse
|
5
|
Beverley KM, Levitan I. Cholesterol regulation of mechanosensitive ion channels. Front Cell Dev Biol 2024; 12:1352259. [PMID: 38333595 PMCID: PMC10850386 DOI: 10.3389/fcell.2024.1352259] [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: 12/07/2023] [Accepted: 01/17/2024] [Indexed: 02/10/2024] Open
Abstract
The purpose of this review is to evaluate the role of cholesterol in regulating mechanosensitive ion channels. Ion channels discussed in this review are sensitive to two types of mechanical signals, fluid shear stress and/or membrane stretch. Cholesterol regulates the channels primarily in two ways: 1) indirectly through localizing the channels into cholesterol-rich membrane domains where they interact with accessory proteins and/or 2) direct binding of cholesterol to the channel at specified putative binding sites. Cholesterol may also regulate channel function via changes of the biophysical properties of the membrane bilayer. Changes in cholesterol affect both mechanosensitivity and basal channel function. We focus on four mechanosensitive ion channels in this review Piezo, Kir2, TRPV4, and VRAC channels. Piezo channels were shown to be regulated by auxiliary proteins that enhance channel function in high cholesterol domains. The direct binding mechanism was shown in Kir2.1 and TRPV4 where cholesterol inhibits channel function. Finally, cholesterol regulation of VRAC was attributed to changes in the physical properties of lipid bilayer. Additional studies should be performed to determine the physiological implications of these sterol effects in complex cellular environments.
Collapse
Affiliation(s)
- Katie M. Beverley
- Division of Pulmonary, Critical Care, Sleep, and Allergy, Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Irena Levitan
- Division of Pulmonary, Critical Care, Sleep, and Allergy, Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| |
Collapse
|
6
|
Okada Y. Physiology of the volume-sensitive/regulatory anion channel VSOR/VRAC. Part 1: from its discovery and phenotype characterization to the molecular entity identification. J Physiol Sci 2024; 74:3. [PMID: 38238667 PMCID: PMC10795261 DOI: 10.1186/s12576-023-00897-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 12/27/2023] [Indexed: 01/22/2024]
Abstract
The volume-sensitive outwardly rectifying or volume-regulated anion channel, VSOR/VRAC, which was discovered in 1988, is expressed in most vertebrate cell types and is essentially involved in cell volume regulation after swelling and in the induction of cell death. This series of review articles describes what is already known and what remains to be uncovered about the functional and molecular properties as well as the physiological and pathophysiological roles of VSOR/VRAC. This Part 1 review article describes, from the physiological standpoint, first its discovery and significance in cell volume regulation, second its phenotypical properties, and third its molecular identification. Although the pore-forming core molecules and the volume-sensing subcomponent of VSOR/VRAC were identified as LRRC8 members and TRPM7 in 2014 and 2021, respectively, it is stressed that the identification of the molecular entity of VSOR/VRAC is still not complete enough to explain the full set of phenotypical properties.
Collapse
Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
- Department of Integrative Physiology, Graduate School of Medicine, Akita University, Akita, Japan.
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, Japan.
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
- Cardiovascular Research Institute, Yokohama City University, Yokohama, Japan.
- Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan.
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
Tranter JD, Kumar A, Nair VK, Sah R. Mechanosensing in Metabolism. Compr Physiol 2023; 14:5269-5290. [PMID: 38158369 DOI: 10.1002/cphy.c230005] [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] [Indexed: 01/03/2024]
Abstract
Electrical mechanosensing is a process mediated by specialized ion channels, gated directly or indirectly by mechanical forces, which allows cells to detect and subsequently respond to mechanical stimuli. The activation of mechanosensitive (MS) ion channels, intrinsically gated by mechanical forces, or mechanoresponsive (MR) ion channels, indirectly gated by mechanical forces, results in electrical signaling across lipid bilayers, such as the plasma membrane. While the functions of mechanically gated channels within a sensory context (e.g., proprioception and touch) are well described, there is emerging data demonstrating functions beyond touch and proprioception, including mechanoregulation of intracellular signaling and cellular/systemic metabolism. Both MR and MS ion channel signaling have been shown to contribute to the regulation of metabolic dysfunction, including obesity, insulin resistance, impaired insulin secretion, and inflammation. This review summarizes our current understanding of the contributions of several MS/MR ion channels in cell types implicated in metabolic dysfunction, namely, adipocytes, pancreatic β-cells, hepatocytes, and skeletal muscle cells, and discusses MS/MR ion channels as possible therapeutic targets. © 2024 American Physiological Society. Compr Physiol 14:5269-5290, 2024.
Collapse
Affiliation(s)
- John D Tranter
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Ashutosh Kumar
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Vinayak K Nair
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Rajan Sah
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
- Center for Cardiovascular Research, Washington University, St. Louis, Missouri, USA
- St. Louis VA Medical Center, St. Louis, Missouri, USA
| |
Collapse
|
9
|
Solari E, Marcozzi C, Negrini D, Moriondo A. Fluid Osmolarity Modulates the Rate of Spontaneous Contraction of Lymphatic Vessels and Lymph Flow by Means of a Cooperation between TRPV and VRAC Channels. BIOLOGY 2023; 12:1039. [PMID: 37508468 PMCID: PMC10376700 DOI: 10.3390/biology12071039] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/13/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023]
Abstract
Lymphatic vessels are capable of sustaining lymph formation and propulsion via an intrinsic mechanism based on the spontaneous contraction of the lymphatic muscle in the wall of lymphatic collectors. Exposure to a hyper- or hypo-osmolar environment can deeply affect the intrinsic contraction rate and therefore alter lymph flow. In this work, we aimed at defining the putative receptors underlying such a response. Functional experiments were conducted in ex vivo rat diaphragmatic specimens containing spontaneously contracting lymphatic vessels that were exposed to either hyper- or hypo-osmolar solutions. Lymphatics were challenged with blockers to TRPV4, TRPV1, and VRAC channels, known to respond to changes in osmolarity and/or cell swelling and expressed by lymphatic vessels. Results show that the normal response to a hyperosmolar environment is a steady decrease in the contraction rate and lymph flow and can be prevented by blocking TRPV1 channels with capsazepine. The response to a hyposmolar environment consists of an early phase of an increase in the contraction rate, followed by a decrease. The early phase is abolished by blocking VRACs with DCPIB, while blocking TRPV4 mainly resulted in a delay of the early response. Overall, our data suggest that the cooperation of the three channels can shape the response of lymphatic vessels in terms of contraction frequency and lymph flow, with a prominent role of TRPV1 and VRACs.
Collapse
Affiliation(s)
- Eleonora Solari
- Department of Medicine and Technological Innovation (DIMIT), Università degli Studi dell'Insubria, 21100 Varese, Italy
| | - Cristiana Marcozzi
- Department of Medicine and Technological Innovation (DIMIT), Università degli Studi dell'Insubria, 21100 Varese, Italy
| | - Daniela Negrini
- Department of Medicine and Technological Innovation (DIMIT), Università degli Studi dell'Insubria, 21100 Varese, Italy
| | - Andrea Moriondo
- Department of Medicine and Technological Innovation (DIMIT), Università degli Studi dell'Insubria, 21100 Varese, Italy
| |
Collapse
|
10
|
Liu T, Li Y, Wang D, Stauber T, Zhao J. Trends in volume-regulated anion channel (VRAC) research: visualization and bibliometric analysis from 2014 to 2022. Front Pharmacol 2023; 14:1234885. [PMID: 37538172 PMCID: PMC10394876 DOI: 10.3389/fphar.2023.1234885] [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: 06/05/2023] [Accepted: 07/10/2023] [Indexed: 08/05/2023] Open
Abstract
Objective: In this study, we utilized bibliometric methods to assess the worldwide scientific output and identify hotspots related to the research on the volume-regulated anion channel (VRAC) from 2014 to 2022. Methods: From Web of Science, we obtained studies related to VRAC published from 2014 to 2022. To analyzed the data, we utilized VOSviewer, a tool for visualizing network, to create networks based on the collaboration between countries, institutions, and authors. Additionally, we performed an analysis of journal co-citation, document citation, and co-occurrence of keywords. Furthermore, we employed CiteSpace (6.1. R6 Advanced) to analyzed keywords and co-cited references with the strongest burst. Results: The final analysis included a total of 278 related articles and reviews, covering the period from 2014 to 2022. The United States emerged as the leading country contributing to this field, while the University of Copenhagen stood out as the most prominent institution. The author with most publications and most citations was Thomas J. Jentsch. Among the cited references, the article by Voss et al. published in Science (2014) gained significant attention for its identification of LRRC8 heteromers as a crucial component of the volume-regulated anion channel VRAC. Pflügers Archiv European Journal of Physiology and Journal of Physiology-London were the leading journals in terms of the quantity of associated articles and citations. Through the analysis of keyword co-occurrence, it was discovered that VRAC is involved in various physiological processes including cell growth, migration, apoptosis, swelling, and myogenesis, as well as anion and organic osmolyte transport including chloride, taurine, glutamate and ATP. VRAC is also associated with related ion channels such as TMEM16A, TMEM16F, pannexin, and CFTR, and associated with various diseases including epilepsy, leukodystrophy, atherosclerosis, hypertension, cerebral edema, stroke, and different types of cancer including gastric cancer, glioblastoma and hepatocellular carcinoma. Furthermore, VRAC is involved in anti-tumor drug resistance by regulating the uptake of platinum-based drugs and temozolomide. Additionally, VRAC has been studied in the context of pharmacology involving DCPIB and flavonoids. Conclusion: The aim of this bibliometric analysis is to provide an overall perspective for research on VRAC. VRAC has become a topic of increasing interest, and our analysis shows that it continues to be a prominent area. This study offers insights into the investigation of VRAC channel and may guide researchers in identifying new directions for future research.
Collapse
Affiliation(s)
- Tianbao Liu
- Key Laboratory of Endocrine Glucose & Lipids Metabolism and Brain Aging, Ministry of Education, Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong, China
- Shandong Institute of Endocrine and Metabolic Disease, Jinan, Shandong, China
| | - Yin Li
- Department of Oncology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong Provincial Hospital, Jinan, Shandong, China
| | - Dawei Wang
- Key Laboratory of Endocrine Glucose & Lipids Metabolism and Brain Aging, Ministry of Education, Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong, China
- Shandong Institute of Endocrine and Metabolic Disease, Jinan, Shandong, China
- Department of Endocrinology, Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China
| | - Tobias Stauber
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Jiajun Zhao
- Key Laboratory of Endocrine Glucose & Lipids Metabolism and Brain Aging, Ministry of Education, Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong, China
- Shandong Institute of Endocrine and Metabolic Disease, Jinan, Shandong, China
| |
Collapse
|
11
|
Ahn YH, Tang Y, Illes P. The neuroinflammatory astrocytic P2X7 receptor: Alzheimer's disease, ischemic brain injury, and epileptic state. Expert Opin Ther Targets 2023; 27:763-778. [PMID: 37712394 DOI: 10.1080/14728222.2023.2258281] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/04/2023] [Accepted: 09/08/2023] [Indexed: 09/16/2023]
Abstract
INTRODUCTION Astrocytes have previously been considered as cells supporting neuronal functions, but they are now recognized as active players in maintaining central nervous system (CNS) homeostasis. Astrocytes can communicate with other CNS cells, i.e. through the gliotransmitter ATP and P2X7 receptors (Rs). AREAS COVERED In this review, we will discuss how the P2X7R initiates the release of gliotransmitters and proinflammatory cytokines/chemokines, thereby establishing a dialog between astrocytes and neurons and, in addition, causing neuroinflammation. In astrocytes, dysregulation of P2X7Rs has been associated with neurodegenerative illnesses such as Alzheimer's disease (AD), as well as the consequences of cerebral ischemic injury and status epilepticus (SE). EXPERT OPINION Although all CNS cells are possible sources of ATP release, the targets of this ATP are primarily at microglial cells. However, astrocytes also contain ATP-sensitive P2X7Rs and have in addition the peculiar property over microglia to continuously interact with neurons via not only inflammatory mediators but also gliotransmitters, such as adenosine 5'-triphosphate (ATP), glutamate, γ-amino butyric acid (GABA), and D-serine. Cellular damage arising during AD, cerebral ischemia, and SE via P2X7R activation is superimposed upon the original disease, and their prevention by blood-brain barrier permeable pharmacological antagonists is a valid therapeutic option.
Collapse
Affiliation(s)
- Young Ha Ahn
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu, China
| | - Yong Tang
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu, China
- School of Acupuncture and Tuina, Chengdu University of TCM, Chengdu, China
| | - Peter Illes
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu, China
- Rudolf Boehm Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany
| |
Collapse
|
12
|
Stevanović KS, Čepkenović B, Križak S, Živić MŽ, Todorović NV. Osmotically Activated Anion Current of Phycomyces Blakesleeanus-Filamentous Fungi Counterpart to Vertebrate Volume Regulated Anion Current. J Fungi (Basel) 2023; 9:637. [PMID: 37367573 DOI: 10.3390/jof9060637] [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: 05/08/2023] [Revised: 05/21/2023] [Accepted: 05/26/2023] [Indexed: 06/28/2023] Open
Abstract
Studies of ion currents in filamentous fungi are a prerequisite for forming a complete understanding of their physiology. Cytoplasmic droplets (CDs), obtained from sporangiophores of Phycomyces blakesleeanus, are a model system that enables the characterization of ion currents in the native membrane, including the currents mediated by the channels not yet molecularly identified. Osmotically activated anionic current with outward rectification (ORIC) is a dominant current in the membrane of cytoplasmic droplets under the conditions of hypoosmotic stimulation. We have previously reported remarkable functional similarities of ORIC with the vertebrate volume regulated anionic current (VRAC), such as dose-dependent activation by osmotic difference, ion selectivity sequence, and time and voltage dependent profile of the current. Using the patch clamp method on the CD membrane, we further resolve VRAC-like ORIC characteristics in this paper. We examine the inhibition by extracellular ATP and carbenoxolone, the permeation of glutamate in presence of chloride, selectivity for nitrates, and activation by GTP, and we show its single channel behavior in excised membrane. We propose that ORIC is a functional counterpart of vertebrate VRAC in filamentous fungi, possibly with a similar essential role in anion efflux during cell volume regulation.
Collapse
Affiliation(s)
- Katarina S Stevanović
- Faculty of Biology, Institute of Physiology and Biochemistry, University of Belgrade, Studentski Trg 16, 11158 Belgrade, Serbia
| | - Bogdana Čepkenović
- Faculty of Biology, Institute of Physiology and Biochemistry, University of Belgrade, Studentski Trg 16, 11158 Belgrade, Serbia
| | - Strahinja Križak
- Institute of Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia
| | - Miroslav Ž Živić
- Faculty of Biology, Institute of Physiology and Biochemistry, University of Belgrade, Studentski Trg 16, 11158 Belgrade, Serbia
| | - Nataša V Todorović
- Institute of Biological Research "Siniša Stanković", National Institute of the Republic of Serbia, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| |
Collapse
|
13
|
Balkaya M, Dohare P, Chen S, Schober AL, Fidaleo AM, Nalwalk JW, Sah R, Mongin AA. Conditional deletion of LRRC8A in the brain reduces stroke damage independently of swelling-activated glutamate release. iScience 2023; 26:106669. [PMID: 37182109 PMCID: PMC10173736 DOI: 10.1016/j.isci.2023.106669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 03/03/2023] [Accepted: 04/11/2023] [Indexed: 05/16/2023] Open
Abstract
The ubiquitous volume-regulated anion channels (VRACs) facilitate cell volume control and contribute to many other physiological processes. Treatment with non-specific VRAC blockers or brain-specific deletion of the essential VRAC subunit LRRC8A is highly protective in rodent models of stroke. Here, we tested the widely accepted idea that the harmful effects of VRACs are mediated by release of the excitatory neurotransmitter glutamate. We produced conditional LRRC8A knockout either exclusively in astrocytes or in the majority of brain cells. Genetically modified mice were subjected to an experimental stroke (middle cerebral artery occlusion). The astrocytic LRRC8A knockout yielded no protection. Conversely, the brain-wide LRRC8A deletion strongly reduced cerebral infarction in both heterozygous (Het) and full KO mice. Yet, despite identical protection, Het mice had full swelling-activated glutamate release, whereas KO animals showed its virtual absence. These findings suggest that LRRC8A contributes to ischemic brain injury via a mechanism other than VRAC-mediated glutamate release.
Collapse
Affiliation(s)
- Mustafa Balkaya
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Preeti Dohare
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Sophie Chen
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Alexandra L. Schober
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Antonio M. Fidaleo
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Julia W. Nalwalk
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Rajan Sah
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Alexander A. Mongin
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
- Corresponding author
| |
Collapse
|
14
|
Dale N, Butler J, Dospinescu VM, Nijjar S. Channel-mediated ATP release in the nervous system. Neuropharmacology 2023; 227:109435. [PMID: 36690324 DOI: 10.1016/j.neuropharm.2023.109435] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/10/2023] [Accepted: 01/19/2023] [Indexed: 01/21/2023]
Abstract
ATP is well established as a transmitter and modulator in the peripheral and central nervous system. While conventional exocytotic release of ATP at synapses occurs, this transmitter is unusual in also being released into the extracellular space via large-pored plasma membrane channels. This review considers the channels that are known to be permeable to ATP and some of the functions of channel-mediated ATP release. While the possibility of ATP release via channels mediating volume transmission has been known for some time, localised ATP release via channels at specialised synapses made by taste cells to the afferent nerve has recently been documented in taste buds. This raises the prospect that "channel synapses" may occur in other contexts. However, volume transmission and channel synapses are not necessarily mutually exclusive. We suggest that certain glial cells in the brain stem and hypothalamus, which possess long processes and are known to release ATP, may be candidates for both modes of ATP release -channel-mediated volume transmission in the region of their somata and more localised transmission possibly via either conventional or channel synapses from their processes at distal targets. Finally, we consider the different characteristics of vesicular and channel synapses and suggest that channel synapses may be advantageous in requiring less energy than their conventional vesicular counterparts. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
Collapse
Affiliation(s)
- Nicholas Dale
- School of Life Sciences, University of Warwick, Coventry, CV4, AL, UK.
| | - Jack Butler
- School of Life Sciences, University of Warwick, Coventry, CV4, AL, UK
| | | | - Sarbjit Nijjar
- School of Life Sciences, University of Warwick, Coventry, CV4, AL, UK
| |
Collapse
|
15
|
Saito M, Tanaka C, Toyoda H, Kang Y. Subcellular Localization of Homomeric TASK3 Channels and Its Presumed Functional Significances in Trigeminal Motoneurons. Int J Mol Sci 2022; 24:ijms24010344. [PMID: 36613787 PMCID: PMC9820627 DOI: 10.3390/ijms24010344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/12/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
Somatic expressions of either heteromeric TASK1/3 or homomeric TASK1/1 channels have been reported in various neurons, while expression of homomeric TASK3/3 channels has been re-ported only in dendrites. However, it is not known why homomeric TASK3/3 channels are hardly seen in somata of CNS neurons. Given the absence of somatic TASK3/3 channels, it should be clarified why dendritic expression of TASK3/3 channels is inevitable and necessary and how differentially distributed TASK1/1 and TASK3/3 channels play roles in soma-to-dendritic integration. Here, we addressed these questions. We found that TASK3-transfected HEK293 cells showed decreases in cell volume after being transferred from the cultured medium to HEPES Ringer, suggesting that expressions of TASK3 channels in cell bodies cause an osmolarity problem. Using TASK1- and TASK3-transfected oocytes, we also found that cGMP application slightly suppressed TASK3 currents while it largely enhanced TASK1 currents, alleviating the difference between TASK1 and TASK3 currents at physiological pH. As larger motoneurons have extensive dendritic trees while smaller motoneurons have poor ones, cGMP could integrate Ia-EPSPs to recruit small and large motoneurons synchronously by differentially modulating TASKI and TASK3 channels which were complementary distributed in soma and dendrites of motoneurons in the dorsolateral part of the trigeminal motor nucleus.
Collapse
Affiliation(s)
- Mitsuru Saito
- Department of Oral Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544, Japan
| | - Chie Tanaka
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita 565-0871, Japan
| | - Hiroki Toyoda
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita 565-0871, Japan
- Correspondence: (H.T.); (Y.K.)
| | - Youngnam Kang
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita 565-0871, Japan
- Department of Behavioral Sciences, Osaka University Graduate School of Human Sciences, Suita 565-0871, Japan
- Correspondence: (H.T.); (Y.K.)
| |
Collapse
|
16
|
Serpe C, Michelucci A, Monaco L, Rinaldi A, De Luca M, Familiari P, Relucenti M, Di Pietro E, Di Castro MA, D’Agnano I, Catacuzzeno L, Limatola C, Catalano M. Astrocytes-Derived Small Extracellular Vesicles Hinder Glioma Growth. Biomedicines 2022; 10:biomedicines10112952. [PMID: 36428520 PMCID: PMC9688032 DOI: 10.3390/biomedicines10112952] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 11/07/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022] Open
Abstract
All cells are capable of secreting extracellular vesicles (EVs), which are not a means to eliminate unneeded cellular compounds but represent a process to exchange material (nucleic acids, lipids and proteins) between different cells. This also happens in the brain, where EVs permit the crosstalk between neuronal and non-neuronal cells, functional to homeostatic processes or cellular responses to pathological stimuli. In brain tumors, EVs are responsible for the bidirectional crosstalk between glioblastoma cells and healthy cells, and among them, astrocytes, that assume a pro-tumoral or antitumoral role depending on the stage of the tumor progression. In this work, we show that astrocyte-derived small EVs (sEVs) exert a defensive mechanism against tumor cell growth and invasion. The effect is mediated by astrocyte-derived EVs (ADEVs) through the transfer to tumor cells of factors that hinder glioma growth. We identified one of these factors, enriched in ADEVs, that is miR124. It reduced both the expression and function of the volume-regulated anion channel (VRAC), that, in turn, decreased the cell migration and invasion of murine glioma GL261 cells.
Collapse
Affiliation(s)
- Carmela Serpe
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
| | - Antonio Michelucci
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Lucia Monaco
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
| | - Arianna Rinaldi
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
| | - Mariassunta De Luca
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
| | - Pietro Familiari
- Division of Neurosurgery, Department of Human Neurosciences, Policlinico Umberto I, Sapienza University of Rome, 00185 Rome, Italy
| | - Michela Relucenti
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, Sapienza University, 00185 Rome, Italy
| | - Erika Di Pietro
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
| | | | - Igea D’Agnano
- Institute of Biomedical Technologies, CNR, 20054 Segrate, Italy
| | - Luigi Catacuzzeno
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Cristina Limatola
- Department of Physiology and Pharmacology, Laboratory Affiliated to Istituto Pasteur Italia Fondazione Cenci Bolognetti, Sapienza University, 00185 Rome, Italy
- Correspondence: (C.L.); (M.C.); Tel.: +39-06-49690243 (C.L.); +39-06-49910467 (M.C.)
| | - Myriam Catalano
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
- Correspondence: (C.L.); (M.C.); Tel.: +39-06-49690243 (C.L.); +39-06-49910467 (M.C.)
| |
Collapse
|
17
|
Shcheynikov N, Boggs K, Green A, Feranchak AP. Identification of the chloride channel, leucine-rich repeat-containing protein 8, subfamily a (LRRC8A), in mouse cholangiocytes. Hepatology 2022; 76:1248-1258. [PMID: 35445421 PMCID: PMC10126881 DOI: 10.1002/hep.32536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 12/08/2022]
Abstract
BACKGROUND AND AIMS Chloride (Cl- ) channels in the apical membrane of biliary epithelial cells (BECs), also known as cholangiocytes, provide the driving force for biliary secretion. Although two Cl- channels have been identified on a molecular basis, the Cystic Fibrosis Transmembrane Conductance Regulator and Transmembrane Member 16A, a third Cl- channel with unique biophysical properties has been described. Leucine-Rich Repeat-Containing Protein 8, subfamily A (LRRC8A) is a newly identified protein capable of transporting Cl- in other epithelium in response to cell swelling. The aim of the present study was to determine if LRRC8A represents the volume-regulated anion channel in mouse BECs. APPROACH AND RESULTS Studies were performed in mouse small (MSC) and large (MLC) cholangiocytes. Membrane Cl- currents were measured by whole-cell patch-clamp techniques and cell volume measurements were performed by calcein-AM fluorescence. Exposure of either MSC or MLC to hypotonicity (190 mOsm) rapidly increased cell volume and activated Cl- currents. Currents exhibited outward rectification, time-dependent inactivation at positive membrane potentials, and reversal potential at 0 mV (ECl ). Removal of extracellular Cl- or specific pharmacological inhibition of LRRC8A abolished currents. LRRC8A was detected in both MSC and MLC by reverse transcription polymerase chain reaction and confirmed by western blot. Transfection with LRRC8A small interfering RNA decreased protein levels by >70% and abolished volume-stimulated Cl- currents. CONCLUSION These results demonstrate that LRRC8A is functionally present in mouse BECs, contributes to volume-activated Cl- secretion, and, therefore, may be a target to modulate bile formation in the treatment of cholestatic liver disorders.
Collapse
Affiliation(s)
- Nikolay Shcheynikov
- Department of Pediatrics, University of Pittsburgh Medical Center Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kristy Boggs
- Department of Pediatrics, University of Pittsburgh Medical Center Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anthony Green
- Tissue and Research Pathology Core, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Andrew P Feranchak
- Department of Pediatrics, University of Pittsburgh Medical Center Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
18
|
Hou L, Liu Y, Sun C, Xu R, Cao G, Wang X. Novel Perspective of Cardiovascular Diseases: Volume-Regulatory Anion Channels in the Cell Membrane. MEMBRANES 2022; 12:membranes12070644. [PMID: 35877847 PMCID: PMC9324040 DOI: 10.3390/membranes12070644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/09/2022] [Accepted: 06/18/2022] [Indexed: 11/16/2022]
Abstract
Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide. Although there are established mechanisms and preventions for CVDs, they are not totally elucidative and effective. Emerging evidence suggests that the dysregulation of ion channels in the cell membranes underpins the dysfunction of the cardiovascular system. To date, a variety of cation channels have been widely recognized as important targets for the treatment of CVDs. As a critical component of the anion channels, the volume-regulated anion channel (VRAC) is involved in a series of cell functions by the volume regulation and maintenance of membrane homeostasis. It has been confirmed to play crucial roles in cell action potential generation, cell proliferation, differentiation and apoptosis, and the VRAC appears to be a major participant in metabolic processes during CVDs. This review summarizes the current evidence and progress concerning the VRAC, to determine the future directions and challenges for CVDs for both preventive and therapeutic purposes.
Collapse
|
19
|
Mecawi AS, Varanda WA, da Silva MP. Osmoregulation and the Hypothalamic Supraoptic Nucleus: From Genes to Functions. Front Physiol 2022; 13:887779. [PMID: 35685279 PMCID: PMC9171026 DOI: 10.3389/fphys.2022.887779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/18/2022] [Indexed: 11/13/2022] Open
Abstract
Due to the relatively high permeability to water of the plasma membrane, water tends to equilibrate its chemical potential gradient between the intra and extracellular compartments. Because of this, changes in osmolality of the extracellular fluid are accompanied by changes in the cell volume. Therefore, osmoregulatory mechanisms have evolved to keep the tonicity of the extracellular compartment within strict limits. This review focuses on the following aspects of osmoregulation: 1) the general problems in adjusting the "milieu interieur" to challenges imposed by water imbalance, with emphasis on conceptual aspects of osmosis and cell volume regulation; 2) osmosensation and the hypothalamic supraoptic nucleus (SON), starting with analysis of the electrophysiological responses of the magnocellular neurosecretory cells (MNCs) involved in the osmoreception phenomenon; 3) transcriptomic plasticity of SON during sustained hyperosmolality, to pinpoint the genes coding membrane channels and transporters already shown to participate in the osmosensation and new candidates that may have their role further investigated in this process, with emphasis on those expressed in the MNCs, discussing the relationships of hydration state, gene expression, and MNCs electrical activity; and 4) somatodendritic release of neuropeptides in relation to osmoregulation. Finally, we expect that by stressing the relationship between gene expression and the electrical activity of MNCs, studies about the newly discovered plastic-regulated genes that code channels and transporters in the SON may emerge.
Collapse
Affiliation(s)
- André Souza Mecawi
- Laboratory of Molecular Neuroendocrinology, Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Wamberto Antonio Varanda
- Department of Physiology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Melina Pires da Silva
- Laboratory of Cellular Neuroendocrinology, Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| |
Collapse
|
20
|
Sawicka M, Dutzler R. Regulators of cell volume: The structural and functional properties of anion channels of the LRRC8 family. Curr Opin Struct Biol 2022; 74:102382. [DOI: 10.1016/j.sbi.2022.102382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 11/03/2022]
|
21
|
Kasuya G, Nureki O. Recent Advances in the Structural Biology of the Volume-Regulated Anion Channel LRRC8. Front Pharmacol 2022; 13:896532. [PMID: 35645818 PMCID: PMC9130832 DOI: 10.3389/fphar.2022.896532] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/25/2022] [Indexed: 01/23/2023] Open
Abstract
Members of the leucine-rich repeat-containing 8 (LRRC8) protein family, composed of five LRRC8A-E isoforms, are pore-forming components of the volume-regulated anion channel (VRAC), which is activated by cell swelling and releases chloride ions (Cl−) or other osmolytes to counteract cell swelling. Although the LRRC8 protein family was identified as the molecular entity of VRAC only in 2014, due to recent advances in cryo-electron microscopy (cryo-EM), various LRRC8 structures, including homo-hexameric LRRC8A and LRRC8D structures, as well as inhibitor-bound and synthetic single-domain antibody-bound homo-hexameric LRRC8A structures, have been reported, thus extending our understanding of the molecular mechanisms of this protein family. In this review, we describe the important features of LRRC8 provided by these structures, particularly the overall architectures, and the suggested mechanisms underlying pore inhibition and allosteric modulation by targeting the intracellular leucine-rich repeat (LRR) domain.
Collapse
Affiliation(s)
- Go Kasuya
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University, Shimotsuke, Japan
- *Correspondence: Go Kasuya, ; Osamu Nureki,
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- *Correspondence: Go Kasuya, ; Osamu Nureki,
| |
Collapse
|
22
|
Ellingsrud AJ, Dukefoss DB, Enger R, Halnes G, Pettersen K, Rognes ME. Validating a Computational Framework for Ionic Electrodiffusion with Cortical Spreading Depression as a Case Study. eNeuro 2022; 9:ENEURO.0408-21.2022. [PMID: 35365505 PMCID: PMC9045477 DOI: 10.1523/eneuro.0408-21.2022] [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: 09/24/2021] [Revised: 02/21/2022] [Accepted: 03/12/2022] [Indexed: 11/21/2022] Open
Abstract
Cortical spreading depression (CSD) is a wave of pronounced depolarization of brain tissue accompanied by substantial shifts in ionic concentrations and cellular swelling. Here, we validate a computational framework for modeling electrical potentials, ionic movement, and cellular swelling in brain tissue during CSD. We consider different model variations representing wild-type (WT) or knock-out/knock-down mice and systematically compare the numerical results with reports from a selection of experimental studies. We find that the data for several CSD hallmarks obtained computationally, including wave propagation speed, direct current shift duration, peak in extracellular K+ concentration as well as a pronounced shrinkage of extracellular space (ECS) are well in line with what has previously been observed experimentally. Further, we assess how key model parameters including cellular diffusivity, structural ratios, membrane water and/or K+ permeabilities affect the set of CSD characteristics.
Collapse
Affiliation(s)
- Ada J Ellingsrud
- Department for Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo 0164, Norway
| | - Didrik B Dukefoss
- Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo 0317, Norway
| | - Rune Enger
- Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo 0317, Norway
| | - Geir Halnes
- CINPLA, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo 0316, Norway
- Institute of Physics, Faculty of Science and Technology, Norwegian University of Life Sciences, Ås 1432, Norway
| | - Klas Pettersen
- NORA, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo 0316, Norway
| | - Marie E Rognes
- Department for Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo 0164, Norway
- Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5020, Norway
| |
Collapse
|
23
|
Ion Channel Involvement in Tumor Drug Resistance. J Pers Med 2022; 12:jpm12020210. [PMID: 35207698 PMCID: PMC8878471 DOI: 10.3390/jpm12020210] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/28/2022] [Accepted: 02/02/2022] [Indexed: 11/30/2022] Open
Abstract
Over 90% of deaths in cancer patients are attributed to tumor drug resistance. Resistance to therapeutic agents can be due to an innate property of cancer cells or can be acquired during chemotherapy. In recent years, it has become increasingly clear that regulation of membrane ion channels is an important mechanism in the development of chemoresistance. Here, we review the contribution of ion channels in drug resistance of various types of cancers, evaluating their potential in clinical management. Several molecular mechanisms have been proposed, including evasion of apoptosis, cell cycle arrest, decreased drug accumulation in cancer cells, and activation of alternative escape pathways such as autophagy. Each of these mechanisms leads to a reduction of the therapeutic efficacy of administered drugs, causing more difficulty in cancer treatment. Thus, targeting ion channels might represent a good option for adjuvant therapies in order to counteract chemoresistance development.
Collapse
|
24
|
Kittl M, Winklmayr M, Preishuber-Pflügl J, Strobl V, Gaisberger M, Ritter M, Jakab M. Low pH Attenuates Apoptosis by Suppressing the Volume-Sensitive Outwardly Rectifying (VSOR) Chloride Current in Chondrocytes. Front Cell Dev Biol 2022; 9:804105. [PMID: 35186954 PMCID: PMC8847443 DOI: 10.3389/fcell.2021.804105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/31/2021] [Indexed: 11/25/2022] Open
Abstract
In a variety of physiological and pathophysiological conditions, cells are exposed to acidic environments. Severe synovial fluid acidification also occurs in a progressive state of osteoarthritis (OA) affecting articular chondrocytes. In prior studies extracellular acidification has been shown to protect cells from apoptosis but the underlying mechanisms remain elusive. In the present study, we demonstrate that the inhibition of Cl− currents plays a significant role in the antiapoptotic effect of acidification in human articular chondrocytes. Drug-induced apoptosis was analyzed after exposure to staurosporine by caspase 3/7 activity and by annexin-V/7-actinomycin D (7-AAD) staining, followed by flow cytometry. Cell viability was assessed by resazurin, CellTiter-Glo and CellTiter-Fluor assays. Cl− currents and the mean cell volume were determined using the whole cell patch clamp technique and the Coulter method, respectively. The results reveal that in C28/I2 cells extracellular acidification decreases caspase 3/7 activity, enhances cell viability following staurosporine treatment and gradually deactivates the volume-sensitive outwardly rectifying (VSOR) Cl− current. Furthermore, the regulatory volume decrease (RVD) as well as the apoptotic volume decrease (ADV), which represents an early event during apoptosis, were absent under acidic conditions after hypotonicity-induced cell swelling and staurosporine-induced apoptosis, respectively. Like acidosis, the VSOR Cl− current inhibitor DIDS rescued chondrocytes from apoptotic cell death and suppressed AVD after induction of apoptosis with staurosporine. Similar to acidosis and DIDS, the VSOR channel blockers NPPB, niflumic acid (NFA) and DCPIB attenuated the staurosporine-induced AVD. NPPB and NFA also suppressed staurosporine-induced caspase 3/7 activation, while DCPIB and Tamoxifen showed cytotoxic effects per se. From these data, we conclude that the deactivation of VSOR Cl− currents impairs cell volume regulation under acidic conditions, which is likely to play an important role in the survivability of human articular chondrocytes.
Collapse
Affiliation(s)
- Michael Kittl
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology—Salzburg, Paracelsus Medical University, Salzburg, Austria
- Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Salzburg, Austria
- *Correspondence: Michael Kittl,
| | - Martina Winklmayr
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology—Salzburg, Paracelsus Medical University, Salzburg, Austria
- Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Salzburg, Austria
| | - Julia Preishuber-Pflügl
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology—Salzburg, Paracelsus Medical University, Salzburg, Austria
- Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
| | - Victoria Strobl
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology—Salzburg, Paracelsus Medical University, Salzburg, Austria
- Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
| | - Martin Gaisberger
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology—Salzburg, Paracelsus Medical University, Salzburg, Austria
- Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Salzburg, Austria
- Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
| | - Markus Ritter
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology—Salzburg, Paracelsus Medical University, Salzburg, Austria
- Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Salzburg, Austria
- Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology, Pathophysiology and Biophysics—Nuremberg, Paracelsus Medical University, Nuremberg, Germany
| | - Martin Jakab
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology—Salzburg, Paracelsus Medical University, Salzburg, Austria
- Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Salzburg, Austria
| |
Collapse
|
25
|
Chen L, Chen Y, Xu Y, Shen SG, Dai J. Effect of Swell1 on regulating chondrocyte hypertrophy during the condylar osteochondral development process in mice. Biochem Biophys Res Commun 2022; 590:42-48. [PMID: 34968783 DOI: 10.1016/j.bbrc.2021.12.086] [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: 11/01/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 11/02/2022]
Abstract
Chondrocyte hypertrophy is a significant factor in cartilage development, yet the molecular mechanism for cell volume expand during the process is remains unclear. In the present study, the relationship between Swell1, a cell volume regulated anion channel, and chondrocyte hypertrophy was explored. The results reveal that the spatiotemporal expression of Swell1 was similar with the development process of hypertrophic chondrocytes in condyles. Through Col10a1 mediated knock out of Swell1 in hypertrophy chondrocytes, we found that there are less obvious boundary between different condylar cartilage layers in which increased hypertrophic chondrocytes were scattered in all three cartilage layers. The cortical bone mass and bone mineral density in the subchondral bone significantly increased. Additionally, knock out of Swell1 could increase the expression of OCN in the femur condyle. Based on the aforementioned findings, a conclusion could be drawn that Swell1 is a significant factor in chondrocyte hypertrophy during the condylar osteochondral development process, and there was some difference between the mandibular and femur condyles, which will provide some new clues for understanding the development of cartilage and related diseases.
Collapse
Affiliation(s)
- Long Chen
- Department of Oral and Cranio-maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China
| | - Yu Chen
- Department of Oral and Cranio-maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China
| | - Yanting Xu
- Department of Oral and Cranio-maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China
| | - Steve Gf Shen
- Department of Oral and Cranio-maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China; Shanghai University of Medicine & Health Sciences, Shanghai, China.
| | - Jiewen Dai
- Department of Oral and Cranio-maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China.
| |
Collapse
|
26
|
The Important Role of Ion Transport System in Cervical Cancer. Int J Mol Sci 2021; 23:ijms23010333. [PMID: 35008759 PMCID: PMC8745646 DOI: 10.3390/ijms23010333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 12/26/2021] [Accepted: 12/27/2021] [Indexed: 12/15/2022] Open
Abstract
Cervical cancer is a significant gynecological cancer and causes cancer-related deaths worldwide. Human papillomavirus (HPV) is implicated in the etiology of cervical malignancy. However, much evidence indicates that HPV infection is a necessary but not sufficient cause in cervical carcinogenesis. Therefore, the cellular pathophysiology of cervical cancer is worthy of study. This review summarizes the recent findings concerning the ion transport processes involved in cell volume regulation and intracellular Ca2+ homeostasis of epithelial cells and how these transport systems are themselves regulated by the tumor microenvironment. For cell volume regulation, we focused on the volume-sensitive Cl− channels and K+-Cl− cotransporter (KCC) family, important regulators for ionic and osmotic homeostasis of epithelial cells. Regarding intracellular Ca2+ homeostasis, the Ca2+ store sensor STIM molecules and plasma membrane Ca2+ channel Orai proteins, the predominant Ca2+ entry mechanism in epithelial cells, are discussed. Furthermore, we evaluate the potential of these membrane ion transport systems as diagnostic biomarkers and pharmacological interventions and highlight the challenges.
Collapse
|
27
|
Wilczyński B, Dąbrowska A, Saczko J, Kulbacka J. The Role of Chloride Channels in the Multidrug Resistance. MEMBRANES 2021; 12:38. [PMID: 35054564 PMCID: PMC8781147 DOI: 10.3390/membranes12010038] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/23/2021] [Indexed: 12/19/2022]
Abstract
Nowadays, one of medicine's main and most challenging aims is finding effective ways to treat cancer. Unfortunately, although there are numerous anti-cancerous drugs, such as cisplatin, more and more cancerous cells create drug resistance. Thus, it is equally important to find new medicines and research the drug resistance phenomenon and possibilities to avoid this mechanism. Ion channels, including chloride channels, play an important role in the drug resistance phenomenon. Our article focuses on the chloride channels, especially the volume-regulated channels (VRAC) and CLC chloride channels family. VRAC induces multidrug resistance (MDR) by causing apoptosis connected with apoptotic volume decrease (AVD) and VRAC are responsible for the transport of anti-cancerous drugs such as cisplatin. VRACs are a group of heterogenic complexes made from leucine-rich repetition with 8A (LRRC8A) and a subunit LRRC8B-E responsible for the properties. There are probably other subunits, which can create those channels, for example, TTYH1 and TTYH2. It is also known that the ClC family is involved in creating MDR in mainly two mechanisms-by changing the cell metabolism or acidification of the cell. The most researched chloride channel from this family is the CLC-3 channel. However, other channels are playing an important role in inducing MDR as well. In this paper, we review the role of chloride channels in MDR and establish the role of the channels in the MDR phenomenon.
Collapse
Affiliation(s)
- Bartosz Wilczyński
- Faculty of Medicine, Wroclaw Medical University, L. Pasteura 1, 50-367 Wroclaw, Poland; (B.W.); (A.D.)
| | - Alicja Dąbrowska
- Faculty of Medicine, Wroclaw Medical University, L. Pasteura 1, 50-367 Wroclaw, Poland; (B.W.); (A.D.)
| | - Jolanta Saczko
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland;
| | - Julita Kulbacka
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland;
| |
Collapse
|
28
|
Kovermann P, Kolobkova Y, Franzen A, Fahlke C. Mutations associated with epileptic encephalopathy modify EAAT2 anion channel function. Epilepsia 2021; 63:388-401. [PMID: 34961934 DOI: 10.1111/epi.17154] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/09/2021] [Accepted: 12/09/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Mutations in the gene solute carrier family member 1A2 (SLC1A2) encoding the excitatory amino acid transporter 2 (EAAT2) are associated with severe forms of epileptic encephalopathy. EAAT2 is expressed in glial cells and presynaptic nerve terminals and represents the main l-glutamate uptake carrier in the mammalian brain. It does not only function as a secondary active glutamate transporter, but also as an anion channel. How naturally occurring mutations affect these two transport functions of EAAT2 and how such alterations cause epilepsy is insufficiently understood. METHODS Here we studied the functional consequences of three disease-associated mutations, which predict amino acid exchanges p.Gly82Arg (G82R), p.Leu85Pro (L85P), and p.Pro289Arg (P289R), by heterologous expression in mammalian cells, biochemistry, confocal imaging, and whole-cell patch-clamp recordings of EAAT2 l-glutamate transport and anion current. RESULTS G82R and L85P exchange amino acid residues contribute to the formation of the EAAT anion pore. They enlarge the pore diameter sufficiently to permit the passage of l-glutamate and thus function as l-glutamate efflux pathways. The mutation P289R decreases l-glutamate uptake, but increases anion currents despite a lower membrane expression. SIGNIFICANCE l-glutamate permeability of the EAAT anion pore is an unexpected functional consequence of naturally occurring single amino acid substitutions. l-glutamate efflux through mutant EAAT2 anion channels will cause glutamate excitotoxicity and neuronal hyperexcitability in affected patients. Antagonists that selectively suppress the EAAT anion channel function could serve as therapeutic agents in the future.
Collapse
Affiliation(s)
- Peter Kovermann
- Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Institute of Biological Information Processing, Jülich, Germany
| | - Yulia Kolobkova
- Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Institute of Biological Information Processing, Jülich, Germany
| | - Arne Franzen
- Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Institute of Biological Information Processing, Jülich, Germany
| | - Christoph Fahlke
- Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Institute of Biological Information Processing, Jülich, Germany
| |
Collapse
|
29
|
Yurinskaya VE, Vereninov AA. Cation-Chloride Cotransporters, Na/K Pump, and Channels in Cell Water and Ion Regulation: In silico and Experimental Studies of the U937 Cells Under Stopping the Pump and During Regulatory Volume Decrease. Front Cell Dev Biol 2021; 9:736488. [PMID: 34869320 PMCID: PMC8635019 DOI: 10.3389/fcell.2021.736488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/15/2021] [Indexed: 11/13/2022] Open
Abstract
Cation-coupled chloride cotransporters play a key role in generating the Cl- electrochemical gradient on the cell membrane, which is important for regulation of many cellular processes. However, a quantitative analysis of the interplay between numerous membrane transporters and channels in maintaining cell ionic homeostasis is still undeveloped. Here, we demonstrate a recently developed approach on how to predict cell ionic homeostasis dynamics when stopping the sodium pump in human lymphoid cells U937. The results demonstrate the reliability of the approach and provide the first quantitative description of unidirectional monovalent ion fluxes through the plasma membrane of an animal cell, considering all the main types of cation-coupled chloride cotransporters operating in a system with the sodium pump and electroconductive K+, Na+, and Cl- channels. The same approach was used to study ionic and water balance changes associated with regulatory volume decrease (RVD), a well-known cellular response underlying the adaptation of animal cells to a hypoosmolar environment. A computational analysis of cell as an electrochemical system demonstrates that RVD may happen without any changes in the properties of membrane transporters and channels due to time-dependent changes in electrochemical ion gradients. The proposed approach is applicable when studying truly active regulatory processes mediated by the intracellular signaling network. The developed software can be useful for calculation of the balance of the unidirectional fluxes of monovalent ions across the cell membrane of various cells under various conditions.
Collapse
Affiliation(s)
- Valentina E Yurinskaya
- Laboratory of Cell Physiology, Institute of Cytology, Russian Academy of Sciences, St-Petersburg, Russia
| | - Alexey A Vereninov
- Laboratory of Cell Physiology, Institute of Cytology, Russian Academy of Sciences, St-Petersburg, Russia
| |
Collapse
|
30
|
Kolobkova Y, Pervaiz S, Stauber T. The expanding toolbox to study the LRRC8-formed volume-regulated anion channel VRAC. CURRENT TOPICS IN MEMBRANES 2021; 88:119-163. [PMID: 34862024 DOI: 10.1016/bs.ctm.2021.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The volume-regulated anion channel (VRAC) is activated upon cell swelling and facilitates the passive movement of anions across the plasma membrane in cells. VRAC function underlies many critical homeostatic processes in vertebrate cells. Among them are the regulation of cell volume and membrane potential, glutamate release and apoptosis. VRAC is also permeable for organic osmolytes and metabolites including some anti-cancer drugs and antibiotics. Therefore, a fundamental understanding of VRAC's structure-function relationships, its physiological roles, its utility for therapy of diseases, and the development of compounds modulating its activity are important research frontiers. Here, we describe approaches that have been applied to study VRAC since it was first described more than 30 years ago, providing an overview of the recent methodological progress. The diverse applications reflecting a compromise between the physiological situation, biochemical definition, and biophysical resolution range from the study of VRAC activity using a classic electrophysiology approach, to the measurement of osmolytes transport by various means and the investigation of its activation using a novel biophysical approach based on fluorescence resonance energy transfer.
Collapse
Affiliation(s)
- Yulia Kolobkova
- Department of Human Medicine and Institute for Molecular Medicine, MSH Medical School Hamburg, Germany
| | - Sumaira Pervaiz
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Tobias Stauber
- Department of Human Medicine and Institute for Molecular Medicine, MSH Medical School Hamburg, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany.
| |
Collapse
|
31
|
García-Rodríguez C, Bravo-Tobar ID, Duarte Y, Barrio LC, Sáez JC. Contribution of non-selective membrane channels and receptors in epilepsy. Pharmacol Ther 2021; 231:107980. [PMID: 34481811 DOI: 10.1016/j.pharmthera.2021.107980] [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: 06/09/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/14/2022]
Abstract
Overcoming refractory epilepsy's resistance to the combination of antiepileptic drugs (AED), mitigating side effects, and preventing sudden unexpected death in epilepsy are critical goals for therapy of this disorder. Current therapeutic strategies are based primarily on neurocentric mechanisms, overlooking the participation of astrocytes and microglia in the pathophysiology of epilepsy. This review is focused on a set of non-selective membrane channels (permeable to ions and small molecules), including channels and ionotropic receptors of neurons, astrocytes, and microglia, such as: the hemichannels formed by Cx43 and Panx1; the purinergic P2X7 receptors; the transient receptor potential vanilloid (TRPV1 and TRPV4) channels; calcium homeostasis modulators (CALHMs); transient receptor potential canonical (TRPC) channels; transient receptor potential melastatin (TRPM) channels; voltage-dependent anion channels (VDACs) and volume-regulated anion channels (VRACs), which all have in common being activated by epileptic activity and the capacity to exacerbate seizure intensity. Specifically, we highlight evidence for the activation of these channels/receptors during epilepsy including neuroinflammation and oxidative stress, discuss signaling pathways and feedback mechanisms, and propose the functions of each of them in acute and chronic epilepsy. Studying the role of these non-selective membrane channels in epilepsy and identifying appropriate blockers for one or more of them could provide complementary therapies to better alleviate the disease.
Collapse
Affiliation(s)
- Claudia García-Rodríguez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile.
| | - Iván D Bravo-Tobar
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile
| | - Yorley Duarte
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Luis C Barrio
- Hospital Ramon y Cajal-IRYCIS, Centro de Tecnología Biomédica de la Universidad Politécnica, Madrid, Spain
| | - Juan C Sáez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile.
| |
Collapse
|
32
|
Wilson CS, Dohare P, Orbeta S, Nalwalk JW, Huang Y, Ferland RJ, Sah R, Scimemi A, Mongin AA. Late adolescence mortality in mice with brain-specific deletion of the volume-regulated anion channel subunit LRRC8A. FASEB J 2021; 35:e21869. [PMID: 34469026 PMCID: PMC8639177 DOI: 10.1096/fj.202002745r] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 07/27/2021] [Accepted: 08/09/2021] [Indexed: 11/11/2022]
Abstract
The leucine-rich repeat-containing family 8 member A (LRRC8A) is an essential subunit of the volume-regulated anion channel (VRAC). VRAC is critical for cell volume control, but its broader physiological functions remain under investigation. Recent studies in the field indicate that Lrrc8a disruption in the brain astrocytes reduces neuronal excitability, impairs synaptic plasticity and memory, and protects against cerebral ischemia. In the present work, we generated brain-wide conditional LRRC8A knockout mice (LRRC8A bKO) using NestinCre -driven Lrrc8aflox/flox excision in neurons, astrocytes, and oligodendroglia. LRRC8A bKO animals were born close to the expected Mendelian ratio and developed without overt histological abnormalities, but, surprisingly, all died between 5 and 9 weeks of age with a seizure phenotype, which was confirmed by video and EEG recordings. Brain slice electrophysiology detected changes in the excitability of pyramidal cells and modified GABAergic inputs in the hippocampal CA1 region of LRRC8A bKO. LRRC8A-null hippocampi showed increased immunoreactivity of the astrocytic marker GFAP, indicating reactive astrogliosis. We also found decreased whole-brain protein levels of the GABA transporter GAT-1, the glutamate transporter GLT-1, and the astrocytic enzyme glutamine synthetase. Complementary HPLC assays identified reduction in the tissue levels of the glutamate and GABA precursor glutamine. Together, these findings suggest that VRAC provides vital control of brain excitability in mouse adolescence. VRAC deletion leads to a lethal phenotype involving progressive astrogliosis and dysregulation of astrocytic uptake and supply of amino acid neurotransmitters and their precursors.
Collapse
Affiliation(s)
- Corinne S Wilson
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Preeti Dohare
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Shaina Orbeta
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Julia W Nalwalk
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Yunfei Huang
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Russell J Ferland
- Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, Biddeford, Maine, USA
| | - Rajan Sah
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Annalisa Scimemi
- Department of Biology, University at Albany, State University of New York, Albany, New York, USA
| | - Alexander A Mongin
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| |
Collapse
|
33
|
Sphingosine-1-Phosphate Induces ATP Release via Volume-Regulated Anion Channels in Breast Cell Lines. Life (Basel) 2021; 11:life11080851. [PMID: 34440595 PMCID: PMC8401269 DOI: 10.3390/life11080851] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 12/25/2022] Open
Abstract
High interstitial level of ATP and its lysate adenosine in the cancer microenvironment are considered a halo mark of cancer. Adenosine acts as a strong immune suppressor. However, the source of ATP release is unclear. We clarified the release of ATP via volume-regulated anion channels (VRACs) in breast cell lines using an ATP luminescence imaging system. We detected a slowly rising diffuse pattern of ATP release that was only observed in undifferentiated cells, not in differentiated primary cultured cells. This was confirmed by suppression with DCPIB, a blocker of VRACs, and shRNA for LRRC8A, an indispensable subunit of VRACs. We herein demonstrated that the inflammatory mediator sphingosine-1-phosphate (S1P), which exists abundantly in the cancer microenvironment, induced a diffuse pattern of ATP release isovolumetrically. The response was dose-dependent and suppressed by the knock-down of LRRC8A. It was also suppressed by blockers of S1P receptor 1 and 2 (W146 and JTE013, respectively). RTqPCR demonstrated the prominent presence of S1PR1 and S1PR2 mRNAs. We discussed the roles of S1P-induced ATP release in the cancer microenvironment.
Collapse
|
34
|
Yurinskaya V, Aksenov N, Moshkov A, Goryachaya T, Shemery A, Vereninov A. Flow fluorometry quantification of anion channel VRAC subunit LRRC8A at the membrane of living U937 cells. Channels (Austin) 2021; 14:45-52. [PMID: 32075501 PMCID: PMC7039630 DOI: 10.1080/19336950.2020.1730535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Assessing the expression of channels on the cell membrane is a necessary step in studying the functioning of ion channels in living cells. We explore, first, if endogenous VRAC can be assayed using flow cytometry and a commercially available antibody against an extracellular loop of the LRRC8A, also known as SWELL1, subunit of the VRAC channel. The second goal is to determine if an increase in the number of VRAC channels at the cell membrane is responsible for an increase in chloride permeability of the membrane in two well-known cases: during staurosporine (STS)-induced apoptosis and after water balance disturbance caused by hypotonic medium. Human suspension lymphoid cells U937 were used as they are suitable for flow fluorometry and because we have recently studied their membrane chloride permeability during apoptosis. We found that surface expression of endogenous LRRC8A subunits can be quantified in living U937 cells using flow fluorometry with the Alomone Lab antibody. Further, we revealed that treatment of cells for 1 hour using STS or a hypotonic solution did not change the number of LRRC8A subunits to the extent that would correspond to changes in the membrane chloride permeability determined by ion content analysis. This indicates that prolonged increase in chloride permeability of the cell membrane during apoptotic cell shrinkage or cell volume regulation under hypotonicity in U937 cells occurs without altering cell surface expression of VRAC.
Collapse
Affiliation(s)
| | - Nikolay Aksenov
- Institute of Cytology, Russian Academy of Sciences, St-Petersburg, Russia
| | - Alexey Moshkov
- Institute of Cytology, Russian Academy of Sciences, St-Petersburg, Russia
| | - Tatyana Goryachaya
- Institute of Cytology, Russian Academy of Sciences, St-Petersburg, Russia
| | - Ashley Shemery
- School of Biomedical Sciences, Kent State University, Kent, OH, USA
| | - Alexey Vereninov
- Institute of Cytology, Russian Academy of Sciences, St-Petersburg, Russia
| |
Collapse
|
35
|
van Putten MJ, Fahlke C, Kafitz KW, Hofmeijer J, Rose CR. Dysregulation of Astrocyte Ion Homeostasis and Its Relevance for Stroke-Induced Brain Damage. Int J Mol Sci 2021; 22:5679. [PMID: 34073593 PMCID: PMC8198632 DOI: 10.3390/ijms22115679] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/21/2021] [Accepted: 05/22/2021] [Indexed: 12/14/2022] Open
Abstract
Ischemic stroke is a leading cause of mortality and chronic disability. Either recovery or progression towards irreversible failure of neurons and astrocytes occurs within minutes to days, depending on remaining perfusion levels. Initial damage arises from energy depletion resulting in a failure to maintain homeostasis and ion gradients between extra- and intracellular spaces. Astrocytes play a key role in these processes and are thus central players in the dynamics towards recovery or progression of stroke-induced brain damage. Here, we present a synopsis of the pivotal functions of astrocytes at the tripartite synapse, which form the basis of physiological brain functioning. We summarize the evidence of astrocytic failure and its consequences under ischemic conditions. Special emphasis is put on the homeostasis and stroke-induced dysregulation of the major monovalent ions, namely Na+, K+, H+, and Cl-, and their involvement in maintenance of cellular volume and generation of cerebral edema.
Collapse
Affiliation(s)
- Michel J.A.M. van Putten
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, The Netherlands; (M.J.A.M.v.P.); (J.H.)
| | - Christoph Fahlke
- Institut für Biologische Informationsprozesse, Molekular-und Zellphysiologie (IBI-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Karl W. Kafitz
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| | - Jeannette Hofmeijer
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, The Netherlands; (M.J.A.M.v.P.); (J.H.)
| | - Christine R. Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| |
Collapse
|
36
|
TRPM7 is an essential regulator for volume-sensitive outwardly rectifying anion channel. Commun Biol 2021; 4:599. [PMID: 34017036 PMCID: PMC8137958 DOI: 10.1038/s42003-021-02127-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 04/20/2021] [Indexed: 02/03/2023] Open
Abstract
Animal cells can regulate their volume after swelling by the regulatory volume decrease (RVD) mechanism. In epithelial cells, RVD is attained through KCl release mediated via volume-sensitive outwardly rectifying Cl- channels (VSOR) and Ca2+-activated K+ channels. Swelling-induced activation of TRPM7 cation channels leads to Ca2+ influx, thereby stimulating the K+ channels. Here, we examined whether TRPM7 plays any role in VSOR activation. When TRPM7 was knocked down in human HeLa cells or knocked out in chicken DT40 cells, not only TRPM7 activity and RVD efficacy but also VSOR activity were suppressed. Heterologous expression of TRPM7 in TRPM7-deficient DT40 cells rescued both VSOR activity and RVD, accompanied by an increase in the expression of LRRC8A, a core molecule of VSOR. TRPM7 exerts the facilitating action on VSOR activity first by enhancing molecular expression of LRRC8A mRNA through the mediation of steady-state Ca2+ influx and second by stabilizing the plasmalemmal expression of LRRC8A protein through the interaction between LRRC8A and the C-terminal domain of TRPM7. Therefore, TRPM7 functions as an essential regulator of VSOR activity and LRRC8A expression.
Collapse
|
37
|
Deng Z, Lin Z, Zhong Q, Lu M, Fang H, Liu J, Duan L, Chen L, Wang L, Wang D, Li W. Interleukin 1 beta-induced chloride currents are important in osteoarthritis onset: an in vitro study. Acta Biochim Biophys Sin (Shanghai) 2021; 53:400-409. [PMID: 33677475 PMCID: PMC7996641 DOI: 10.1093/abbs/gmab010] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Indexed: 12/14/2022] Open
Abstract
Persistent hypotonic and inflammatory conditions in the joint cavity can lead to the loss of cartilage matrix and cell death, which are the important mechanisms of osteoarthritis (OA) onset. Previous studies have confirmed that the existence of a hypotonic environment is a red flag for inflammation, as hypotonic environment induces the opening of the chloride channel of the cell and promotes chloride ion efflux, which prompts the cell volume to increase. Chloride channels play an important role in the regulation of mineralization and chondrocyte death. Here, we reported that OA chondrocytes showed a significant increase of cell death rate and the imbalance of cartilage matrix catabolism. We found that the distribution of skeleton protein F-actin was disordered. In addition, the volume-sensitive chloride current of OA chondrocytes decreased significantly with the increase of the expression levels of inflammation-related proteins caspase-1, caspase-3, and NLRP3. Moreover, interleukin-1β (IL-1β) showed a potential to activate the chloride current of normal chondrocytes. These results indicate that IL-1β-induced chloride channel opening in chondrocytes may be closely related to the occurrence of OA. This chloride channel opening process may therefore be a potential target for the treatment of OA.
Collapse
Affiliation(s)
- Zhiqin Deng
- Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Hand and Foot Surgery Department, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen 518000, China
| | - Zicong Lin
- Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Hand and Foot Surgery Department, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen 518000, China
| | - Qing Zhong
- Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Hand and Foot Surgery Department, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen 518000, China
| | - Minqiang Lu
- Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Hand and Foot Surgery Department, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen 518000, China
| | - Huankun Fang
- Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Hand and Foot Surgery Department, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen 518000, China
| | - Jianquan Liu
- Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Hand and Foot Surgery Department, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen 518000, China
| | - Li Duan
- Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Hand and Foot Surgery Department, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen 518000, China
| | - Lixin Chen
- Department of Pharmacology, Medical College, Jinan University, Guangzhou 510632, China
| | - Liwei Wang
- Department of Physiology, Medical College, Jinan University, Guangzhou 510632, China
- International School, Jinan University, Guangzhou 510632, China
| | - Daping Wang
- Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Hand and Foot Surgery Department, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen 518000, China
| | - Wencui Li
- Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Hand and Foot Surgery Department, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen 518000, China
| |
Collapse
|
38
|
Okada Y, Sabirov RZ, Sato-Numata K, Numata T. Cell Death Induction and Protection by Activation of Ubiquitously Expressed Anion/Cation Channels. Part 1: Roles of VSOR/VRAC in Cell Volume Regulation, Release of Double-Edged Signals and Apoptotic/Necrotic Cell Death. Front Cell Dev Biol 2021; 8:614040. [PMID: 33511120 PMCID: PMC7835517 DOI: 10.3389/fcell.2020.614040] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/15/2020] [Indexed: 12/18/2022] Open
Abstract
Cell volume regulation (CVR) is essential for survival and functions of animal cells. Actually, normotonic cell shrinkage and swelling are coupled to apoptotic and necrotic cell death and thus called the apoptotic volume decrease (AVD) and the necrotic volume increase (NVI), respectively. A number of ubiquitously expressed anion and cation channels are involved not only in CVD but also in cell death induction. This series of review articles address the question how cell death is induced or protected with using ubiquitously expressed ion channels such as swelling-activated anion channels, acid-activated anion channels and several types of TRP cation channels including TRPM2 and TRPM7. The Part 1 focuses on the roles of the volume-sensitive outwardly rectifying anion channels (VSOR), also called the volume-regulated anion channel (VRAC), which is activated by cell swelling or reactive oxygen species (ROS) in a manner dependent on intracellular ATP. First we describe phenotypical properties, the molecular identity, and physical pore dimensions of VSOR/VRAC. Second, we highlight the roles of VSOR/VRAC in the release of organic signaling molecules, such as glutamate, glutathione, ATP and cGAMP, that play roles as double-edged swords in cell survival. Third, we discuss how VSOR/VRAC is involved in CVR and cell volume dysregulation as well as in the induction of or protection from apoptosis, necrosis and regulated necrosis under pathophysiological conditions.
Collapse
Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences, Okazaki, Japan
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, Japan
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Ravshan Z. Sabirov
- Laboratory of Molecular Physiology, Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Kaori Sato-Numata
- Japan Society for the Promotion of Science, Tokyo, Japan
- Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan
| | - Tomohiro Numata
- Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan
| |
Collapse
|
39
|
Costa R, Remigante A, Civello DA, Bernardinelli E, Szabó Z, Morabito R, Marino A, Sarikas A, Patsch W, Paulmichl M, Janáky T, Miseta A, Nagy T, Dossena S. O-GlcNAcylation Suppresses the Ion Current IClswell by Preventing the Binding of the Protein ICln to α-Integrin. Front Cell Dev Biol 2020; 8:607080. [PMID: 33330510 PMCID: PMC7717961 DOI: 10.3389/fcell.2020.607080] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 10/23/2020] [Indexed: 12/30/2022] Open
Abstract
O-GlcNAcylation is a post-translational modification of proteins that controls a variety of cellular processes, is chronically elevated in diabetes mellitus, and may contribute to the progression of diabetic complications, including diabetic nephropathy. Our previous work showed that increases in the O-GlcNAcylation of cellular proteins impair the homeostatic reaction of the regulatory volume decrease (RVD) after cell swelling by an unknown mechanism. The activation of the swelling-induced chloride current IClswell is a key step in RVD, and ICln, a ubiquitous protein involved in the activation of IClswell, is O-GlcNAcylated. Here, we show that experimentally increased O-GlcNAcylation of cellular proteins inhibited the endogenous as well as the ICln-induced IClswell current and prevented RVD in a human renal cell line, while decreases in O-GlcNAcylation augmented the current magnitude. In parallel, increases or decreases in O-GlcNAcylation, respectively, weakened or stabilized the binding of ICln to the intracellular domain of α-integrin, a process that is essential for the activation of IClswell. Mutation of the putative YinOYang site at Ser67 rendered the ICln-induced IClswell current unresponsive to O-GlcNAc variations, and the ICln interaction with α-integrin insensitive to O-GlcNAcylation. In addition, exposure of cells to a hypotonic solution reduced the O-GlcNAcylation of cellular proteins. Together, these findings show that O-GlcNAcylation affects RVD by influencing IClswell and further indicate that hypotonicity may activate IClswell by reducing the O-GlcNAcylation of ICln at Ser67, therefore permitting its binding to α-integrin. We propose that disturbances in the regulation of cellular volume may contribute to disease in settings of chronically elevated O-GlcNAcylation, including diabetic nephropathy.
Collapse
Affiliation(s)
- Roberta Costa
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
| | - Alessia Remigante
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria.,Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Davide A Civello
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
| | - Emanuele Bernardinelli
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
| | - Zoltán Szabó
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Rossana Morabito
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Angela Marino
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Antonio Sarikas
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
| | - Wolfgang Patsch
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
| | - Markus Paulmichl
- Department of Personalized Medicine, Humanomed, Klagenfurt, Austria
| | - Tamás Janáky
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Attila Miseta
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary
| | - Tamás Nagy
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary
| | - Silvia Dossena
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
| |
Collapse
|
40
|
Centeio R, Ousingsawat J, Schreiber R, Kunzelmann K. Ca 2+ Dependence of Volume-Regulated VRAC/LRRC8 and TMEM16A Cl - Channels. Front Cell Dev Biol 2020; 8:596879. [PMID: 33335902 PMCID: PMC7736618 DOI: 10.3389/fcell.2020.596879] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/04/2020] [Indexed: 12/31/2022] Open
Abstract
All vertebrate cells activate Cl- currents (ICl ,swell) when swollen by hypotonic bath solution. The volume-regulated anion channel VRAC has now been identified as LRRC8/SWELL1. However, apart from VRAC, the Ca2+-activated Cl- channel (CaCC) TMEM16A and the phospholipid scramblase and ion channel TMEM16F were suggested to contribute to cell swelling-activated whole-cell currents. Cell swelling was shown to induce Ca2+ release from the endoplasmic reticulum and to cause subsequent Ca2+ influx. It is suggested that TMEM16A/F support intracellular Ca2+ signaling and thus Ca2+-dependent activation of VRAC. In the present study, we tried to clarify the contribution of TMEM16A to ICl ,swell. In HEK293 cells coexpressing LRRC8A and LRRC8C, we found that activation of ICl ,swell by hypotonic bath solution (Hypo; 200 mosm/l) was Ca2+ dependent. TMEM16A augmented the activation of LRRC8A/C by enhancing swelling-induced local intracellular Ca2+ concentrations. In HT29 cells, knockdown of endogenous TMEM16A attenuated ICl ,swell and changed time-independent swelling-activated currents to VRAC-typical time-dependent currents. Activation of ICl ,swell by Hypo was attenuated by blocking receptors for inositol trisphosphate and ryanodine (IP3R; RyR), as well as by inhibiting Ca2+ influx. The data suggest that TMEM16A contributes directly to ICl ,swell as it is activated through swelling-induced Ca2+ increase. As activation of VRAC is shown to be Ca2+-dependent, TMEM16A augments VRAC currents by facilitating Hypo-induced Ca2+ increase in submembraneous signaling compartments by means of ER tethering.
Collapse
Affiliation(s)
| | | | | | - Karl Kunzelmann
- Physiological Institute, University of Regensburg, Regensburg, Germany
| |
Collapse
|
41
|
Zhang N, Deng Z, Li W, Zou Y, Xiong J, Duan L, Wang D. Expression of LRRC8A is elevated in the cytoplasm of osteosarcoma tissues: An immunohistochemical study with tissue microarrays. Exp Ther Med 2020; 21:71. [PMID: 33365071 PMCID: PMC7716646 DOI: 10.3892/etm.2020.9503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/28/2020] [Indexed: 01/18/2023] Open
Abstract
The purpose of the present study was to investigate the expression profile of leucine-rich repeat-containing protein 8A (LRRC8A) in osteosarcoma and normal cortical bone, as well as its association with sex, age and tumor malignancy. Immunohistochemical staining of osteosarcoma tissue microarrays (TMAs) was performed to determine the protein expression of LRRC8A and compare them among different subgroups. The expression of LRRC8A in the nuclei and cytoplasm of U2OS tumor cells and MC3T3-E1 osteoblast-like cells was determined using reverse transcription-quantitative PCR. Of all samples of the TMA for patients with osteosarcoma that were tested, 94% featured high cytoplasmic expression of LRRC8A, while in all normal bone tissue control groups, the gene was mainly expressed in the nucleus. In MC3T3-E1 osteoblasts, the expression of LRRC8A at the RNA level was mainly in the cytoplasm. The difference in expression of LRRC8A between microarrays and osteoblasts was statistically significant. In U2OS osteosarcoma cells, LRRC8A mRNA was concentrated in the nuclei and cytoplasm. In osteosarcoma, the expression level of LRRC8A was not significantly associated with sex or age. In conclusion, LRRC8A was highly expressed in the cytoplasm of osteosarcoma cells and the degree of expression may be associated with the degree of tumor malignancy.
Collapse
Affiliation(s)
- Ningfeng Zhang
- Key Laboratory of Tissue Engineering, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong 518000, P.R. China
| | - Zhiqin Deng
- Key Laboratory of Tissue Engineering, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong 518000, P.R. China
| | - Wencui Li
- Key Laboratory of Tissue Engineering, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong 518000, P.R. China
| | - Yan Zou
- Key Laboratory of Tissue Engineering, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong 518000, P.R. China
| | - Jianyi Xiong
- Key Laboratory of Tissue Engineering, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong 518000, P.R. China
| | - Li Duan
- Key Laboratory of Tissue Engineering, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong 518000, P.R. China
| | - Daping Wang
- Key Laboratory of Tissue Engineering, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong 518000, P.R. China
| |
Collapse
|
42
|
Bortner CD, Cidlowski JA. Ions, the Movement of Water and the Apoptotic Volume Decrease. Front Cell Dev Biol 2020; 8:611211. [PMID: 33324655 PMCID: PMC7723978 DOI: 10.3389/fcell.2020.611211] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/04/2020] [Indexed: 12/20/2022] Open
Abstract
The movement of water across the cell membrane is a natural biological process that occurs during growth, cell division, and cell death. Many cells are known to regulate changes in their cell volume through inherent compensatory regulatory mechanisms. Cells can sense an increase or decrease in their cell volume, and compensate through mechanisms known as a regulatory volume increase (RVI) or decrease (RVD) response, respectively. The transport of sodium, potassium along with other ions and osmolytes allows the movement of water in and out of the cell. These compensatory volume regulatory mechanisms maintain a cell at near constant volume. A hallmark of the physiological cell death process known as apoptosis is the loss of cell volume or cell shrinkage. This loss of cell volume is in stark contrast to what occurs during the accidental cell death process known as necrosis. During necrosis, cells swell or gain water, eventually resulting in cell lysis. Thus, whether a cell gains or loses water after injury is a defining feature of the specific mode of cell death. Cell shrinkage or the loss of cell volume during apoptosis has been termed apoptotic volume decrease or AVD. Over the years, this distinguishing feature of apoptosis has been largely ignored and thought to be a passive occurrence or simply a consequence of the cell death process. However, studies on AVD have defined an underlying movement of ions that result in not only the loss of cell volume, but also the activation and execution of the apoptotic process. This review explores the role ions play in controlling not only the movement of water, but the regulation of apoptosis. We will focus on what is known about specific ion channels and transporters identified to be involved in AVD, and how the movement of ions and water change the intracellular environment leading to stages of cell shrinkage and associated apoptotic characteristics. Finally, we will discuss these concepts as they apply to different cell types such as neurons, cardiomyocytes, and corneal epithelial cells.
Collapse
Affiliation(s)
- Carl D. Bortner
- Signal Transduction Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
| | - John A. Cidlowski
- Signal Transduction Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
| |
Collapse
|
43
|
Kittl M, Winklmayr M, Helm K, Lettner J, Gaisberger M, Ritter M, Jakab M. Acid- and Volume-Sensitive Chloride Currents in Human Chondrocytes. Front Cell Dev Biol 2020; 8:583131. [PMID: 33282866 PMCID: PMC7691427 DOI: 10.3389/fcell.2020.583131] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/13/2020] [Indexed: 12/18/2022] Open
Abstract
Chondrocytes face extreme alterations of extracellular osmolarity and pH, which force them to appropriately regulate their cell volume (CV) and cellular pH. Perturbations of these mechanisms lead to chondrocyte death and ultimately to osteoarthritis (OA), the most common chronic joint diseases worldwide. OA hallmarks are altered cartilage hydration and severe fluid acidification. Impaired CV regulation and acidotoxicity contribute to disease progression and volume-sensitive anion channels are upregulated in OA. This study assessed the effect of hypotonicity and extracellular acidification on chondrocyte Cl– conductances and CV regulation. Cl– currents and membrane potentials were measured in human C28/I2 cells and primary human chondrocytes using the patch clamp technique. Intracellular pH was assessed by BCECF fluorescence, CV measurements were performed using the Coulter method, and cell viability/cell death by a resazurin assay. Hypotonic cell swelling caused activation of a volume-sensitive outwardly rectifying (VSOR) Cl– current followed by a regulatory volume decrease (RVD), which was attenuated by the Cl– channel blocker DCPIB. Extracellular, but not intracellular acidification to pH ≤ 5.0 elicited an acid-sensitive outwardly rectifying (ASOR) Cl– conductance. Activation of either current depolarized the cell membrane potential. Under simultaneous hypotonic and acidic stimulation, VSOR and ASOR currents transiently coactivated, giving rise to a mixed current phenotype. Over time the VSOR current gradually vanished and the residual conductance showed a pure ASOR current phenotype. Extracellular acidification caused an isotonic CV gain and a complete suppression of RVD under hypotonic conditions. The results suggest that deactivation of the VSOR current under acidic conditions impairs CV regulation in chondrocytes, which is likely to compromise chondrocyte viability.
Collapse
Affiliation(s)
- Michael Kittl
- Institute of Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria
| | - Martina Winklmayr
- Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Paracelsus Medical University, Salzburg, Austria
| | - Katharina Helm
- Institute of Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria
| | - Johannes Lettner
- Institute of Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria
| | - Martin Gaisberger
- Institute of Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria.,Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Paracelsus Medical University, Salzburg, Austria.,Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
| | - Markus Ritter
- Institute of Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria.,Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Paracelsus Medical University, Salzburg, Austria.,Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
| | - Martin Jakab
- Institute of Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria
| |
Collapse
|
44
|
Yurinskaya VE, Vereninov IA, Vereninov AA. Balance of Na +, K +, and Cl - Unidirectional Fluxes in Normal and Apoptotic U937 Cells Computed With All Main Types of Cotransporters. Front Cell Dev Biol 2020; 8:591872. [PMID: 33240889 PMCID: PMC7677585 DOI: 10.3389/fcell.2020.591872] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 09/30/2020] [Indexed: 12/30/2022] Open
Abstract
Fluxes of monovalent ions through the multiple pathways of the plasma membrane are highly interdependent, and their assessment by direct measurement is difficult or even impossible. Computation of the entire flux balance helps to identify partial flows and study the functional expression of individual transporters. Our previous computation of unidirectional fluxes in real cells ignored the ubiquitous cotransporters NKCC and KCC. Here, we present an analysis of the entire balance of unidirectional Na+, K+, and Cl- fluxes through the plasma membrane in human lymphoid U937 cells, taking into account not only the Na/K pump and electroconductive channels but all major types of cotransporters NC, NKCC, and KCC. Our calculations use flux equations based on the fundamental principles of macroscopic electroneutrality of the system, water balance, and the generally accepted thermodynamic dependence of ion fluxes on the driving force, and they do not depend on hypotheses about the molecular structure of the channel and transporters. A complete list of the major inward and outward Na+, K+, and Cl- fluxes is obtained for human lymphoid U937 cells at rest and during changes in the ion and water balance for the first 4 h of staurosporine-induced apoptosis. It is shown how the problem of the inevitable multiplicity of solutions to the flux equations, which arises with an increase in the number of ion pathways, can be solved in real cases by analyzing the ratio of ouabain-sensitive and ouabain-resistant parts of K+ (Rb+) influx (OSOR) and using additional experimental data on the effects of specific inhibitors. It is found that dynamics of changes in the membrane channels and transporters underlying apoptotic changes in the content of ions and water in cells, calculated without taking into account the KCC and NKCC cotransporters, differs only in details from that calculated for cells with KCC and NKCC. The developed approach to the assessment of unidirectional fluxes may be useful for understanding functional expression of ion channels and transporters in other cells under various conditions. Attached software allows reproduction of all calculated data under presented conditions and to study the effects of the condition variation.
Collapse
Affiliation(s)
- Valentina E Yurinskaya
- Laboratory of Cell Physiology, Institute of Cytology, Russian Academy of Sciences, St-Petersburg, Russia
| | - Igor A Vereninov
- Peter the Great St-Petersburg Polytechnic University, St-Petersburg, Russia
| | - Alexey A Vereninov
- Laboratory of Cell Physiology, Institute of Cytology, Russian Academy of Sciences, St-Petersburg, Russia
| |
Collapse
|
45
|
Shimizu T, Fujii T, Sakai H. The Relationship Between Actin Cytoskeleton and Membrane Transporters in Cisplatin Resistance of Cancer Cells. Front Cell Dev Biol 2020; 8:597835. [PMID: 33195280 PMCID: PMC7655133 DOI: 10.3389/fcell.2020.597835] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 10/05/2020] [Indexed: 12/13/2022] Open
Abstract
Cisplatin [cis-diamminedichloroplatinum (II)] is a platinum-based anticancer drug widely used for the treatment of various cancers. It forms interstrand and intrastrand cross-linking with DNA and block DNA replication, resulting in apoptosis. On the other hand, intrinsic and acquired cisplatin resistance restricts its therapeutic effects. Although some studies suggest that dramatic epigenetic alternations are involved in the resistance triggered by cisplatin, the mechanism is complicated and remains poorly understood. Recent studies reported that cytoskeletal structures regulate cisplatin sensitivity and that activities of membrane transporters contribute to the development of resistance to cisplatin. Therefore, we focus on the roles of actin filaments and membrane transporters in cisplatin-induced apoptosis. In this review, we summarize the relationship between actin cytoskeleton and membrane transporters in the cisplatin resistance of cancer cells.
Collapse
Affiliation(s)
- Takahiro Shimizu
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Takuto Fujii
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Hideki Sakai
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| |
Collapse
|
46
|
Kumar A, Xie L, Ta CM, Hinton AO, Gunasekar SK, Minerath RA, Shen K, Maurer JM, Grueter CE, Abel ED, Meyer G, Sah R. SWELL1 regulates skeletal muscle cell size, intracellular signaling, adiposity and glucose metabolism. eLife 2020; 9:58941. [PMID: 32930093 PMCID: PMC7541086 DOI: 10.7554/elife.58941] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/07/2020] [Indexed: 12/26/2022] Open
Abstract
Maintenance of skeletal muscle is beneficial in obesity and Type 2 diabetes. Mechanical stimulation can regulate skeletal muscle differentiation, growth and metabolism; however, the molecular mechanosensor remains unknown. Here, we show that SWELL1 (Lrrc8a) functionally encodes a swell-activated anion channel that regulates PI3K-AKT, ERK1/2, mTOR signaling, muscle differentiation, myoblast fusion, cellular oxygen consumption, and glycolysis in skeletal muscle cells. LRRC8A over-expression in Lrrc8a KO myotubes boosts PI3K-AKT-mTOR signaling to supra-normal levels and fully rescues myotube formation. Skeletal muscle-targeted Lrrc8a KO mice have smaller myofibers, generate less force ex vivo, and exhibit reduced exercise endurance, associated with increased adiposity under basal conditions, and glucose intolerance and insulin resistance when raised on a high-fat diet, compared to wild-type (WT) mice. These results reveal that the LRRC8 complex regulates insulin-PI3K-AKT-mTOR signaling in skeletal muscle to influence skeletal muscle differentiation in vitro and skeletal myofiber size, muscle function, adiposity and systemic metabolism in vivo.
Collapse
Affiliation(s)
- Ashutosh Kumar
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, United States
| | - Litao Xie
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, United States
| | - Chau My Ta
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, United States
| | - Antentor O Hinton
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, United States.,Division of Endocrinology and Metabolism, Iowa City, United States
| | - Susheel K Gunasekar
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, United States
| | - Rachel A Minerath
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, United States.,Division of Cardiology, University of Iowa, Iowa City, United States
| | - Karen Shen
- Program in Physical Therapy and Departments of Neurology, Biomedical Engineering and Orthopedic Surgery, Washington University in St. Louis, St. Louis, United States
| | - Joshua M Maurer
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, United States
| | - Chad E Grueter
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, United States.,Division of Cardiology, University of Iowa, Iowa City, United States
| | - E Dale Abel
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, United States.,Division of Endocrinology and Metabolism, Iowa City, United States
| | - Gretchen Meyer
- Program in Physical Therapy and Departments of Neurology, Biomedical Engineering and Orthopedic Surgery, Washington University in St. Louis, St. Louis, United States
| | - Rajan Sah
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, United States
| |
Collapse
|
47
|
Chen BY, Huang CC, Lv XF, Zheng HQ, Zhang YJ, Sun L, Wang GL, Ma MM, Guan YY. SGK1 mediates the hypotonic protective effect against H 2O 2-induced apoptosis of rat basilar artery smooth muscle cells by inhibiting the FOXO3a/Bim signaling pathway. Acta Pharmacol Sin 2020; 41:1073-1084. [PMID: 32139897 PMCID: PMC7470837 DOI: 10.1038/s41401-020-0357-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/01/2020] [Indexed: 01/31/2023] Open
Abstract
Serum- and glucocorticoid-inducible kinease-1 (SGK1) is a serine/threonine kinase regulated by hypotonic stimuli, which is involved in regulation of cell cycle and apoptosis. Our previous study shows that activation of volume-regulated Cl- channels (VRCCs) protects rat basilar artery smooth muscle cells (BASMCs) against hydrogen peroxide (H2O2)-induced apoptosis. In the present study, we investigated whether SGK1 was involved in the protective effect of VRCCs in BASMCs. We showed that hypotonic challenge significantly reduced H2O2-induced apoptosis, and increased SGK1 phosphorylation, but did not affect SGK1 protein expression. The protective effect of hypotonic challenge against H2O2-induced apoptosis was mediated through inhibiting mitochondria-dependent apoptotic pathway, evidenced by increased Bcl-2/Bax ratio, stabilizing mitochondrial membrane potential (MMP), decreased cytochrome c release from the mitochondria to the cytoplasm, and inhibition of the activation of caspase-9 and caspase-3. These protective effects of hypotonic challenge against H2O2-induced apoptosis was diminished and enhanced, respectively, by SGK1 knockdown and overexpression. We further revealed that SGK1 activation significantly increased forkhead box O3a (FOXO3a) phosphorylation, and then inhibited the translocation of FOXO3a into nucleus and the subsequent expression of Bcl-2 interacting mediator of cell death (Bim). In conclusion, SGK1 mediates the protective effect of VRCCs against H2O2-induced apoptosis in BASMCs via inhibiting FOXO3a/Bim signaling pathway. Our results provide compelling evidences that SGK1 is a critical link between VRCCs and apoptosis, and shed a new light on the treatment of vascular apoptosis-associated diseases, such as vascular remodeling, angiogenesis, and atherosclerosis.
Collapse
|
48
|
Nakamura R, Numata T, Kasuya G, Yokoyama T, Nishizawa T, Kusakizako T, Kato T, Hagino T, Dohmae N, Inoue M, Watanabe K, Ichijo H, Kikkawa M, Shirouzu M, Jentsch TJ, Ishitani R, Okada Y, Nureki O. Cryo-EM structure of the volume-regulated anion channel LRRC8D isoform identifies features important for substrate permeation. Commun Biol 2020; 3:240. [PMID: 32415200 PMCID: PMC7229184 DOI: 10.1038/s42003-020-0951-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/17/2020] [Indexed: 11/10/2022] Open
Abstract
Members of the leucine-rich repeat-containing 8 (LRRC8) protein family, composed of the five LRRC8A-E isoforms, are pore-forming components of the volume-regulated anion channel (VRAC). LRRC8A and at least one of the other LRRC8 isoforms assemble into heteromers to generate VRAC transport activities. Despite the availability of the LRRC8A structures, the structural basis of how LRRC8 isoforms other than LRRC8A contribute to the functional diversity of VRAC has remained elusive. Here, we present the structure of the human LRRC8D isoform, which enables the permeation of organic substrates through VRAC. The LRRC8D homo-hexamer structure displays a two-fold symmetric arrangement, and together with a structure-based electrophysiological analysis, revealed two key features. The pore constriction on the extracellular side is wider than that in the LRRC8A structures, which may explain the increased permeability of organic substrates. Furthermore, an N-terminal helix protrudes into the pore from the intracellular side and may be critical for gating.
Collapse
Affiliation(s)
- Ryoki Nakamura
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Tomohiro Numata
- Department of Physiology, Graduate School of Medical Sciences, Fukuoka University, 7-45-1 Nanakuma, Johnan-ku, Fukuoka, Japan
| | - Go Kasuya
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, Japan.
| | - Takeshi Yokoyama
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa, Japan
| | - Tomohiro Nishizawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Tsukasa Kusakizako
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Takafumi Kato
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Tatsuya Hagino
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan
| | - Masato Inoue
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Kengo Watanabe
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Hidenori Ichijo
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Masahide Kikkawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Mikako Shirouzu
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa, Japan
| | - Thomas J Jentsch
- Physiology and Pathology of Ion Transport, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin, D-13125, Berlin, Germany
| | - Ryuichiro Ishitani
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Yasunobu Okada
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
- Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki, Japan.
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
| |
Collapse
|
49
|
Shimizu T, Fujii T, Ohtake H, Tomii T, Takahashi R, Kawashima K, Sakai H. Impaired actin filaments decrease cisplatin sensitivity via dysfunction of volume-sensitive Cl - channels in human epidermoid carcinoma cells. J Cell Physiol 2020; 235:9589-9600. [PMID: 32372464 DOI: 10.1002/jcp.29767] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 04/27/2020] [Accepted: 04/27/2020] [Indexed: 01/20/2023]
Abstract
Cisplatin is a widely used platinum-based anticancer drug in the chemotherapy of numerous human cancers. However, cancer cells acquire resistance to cisplatin. So far, functional loss of volume-sensitive outwardly rectifying (VSOR) Cl- channels has been reported to contribute to cisplatin resistance of cancer cells. Here, we analyzed protein expression patterns of human epidermoid carcinoma KB cells and its cisplatin-resistant KCP-4 cells. Intriguingly, KB cells exhibited higher β-actin expression and clearer actin filaments than KCP-4 cells. The β-actin knockdown in KB cells decreased VSOR Cl- currents and inhibited the regulatory volume decrease (RVD) process after cell swelling. Consistently, KB cells treated with cytochalasin D, which depolymerizes actin filaments, showed smaller VSOR Cl- currents and slower RVD. Cytochalasin D also inhibited cisplatin-triggered apoptosis in KB cells. These results suggest that the disruption of actin filaments cause the dysfunction of VSOR Cl- channels, which elicits resistance to cisplatin in human epidermoid carcinoma cells.
Collapse
Affiliation(s)
- Takahiro Shimizu
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Takuto Fujii
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Hironao Ohtake
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Toshie Tomii
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Ryuta Takahashi
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Kentaro Kawashima
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Hideki Sakai
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| |
Collapse
|
50
|
Zhou C, Chen X, Planells-Cases R, Chu J, Wang L, Cao L, Li Z, López-Cayuqueo KI, Xie Y, Ye S, Wang X, Ullrich F, Ma S, Fang Y, Zhang X, Qian Z, Liang X, Cai SQ, Jiang Z, Zhou D, Leng Q, Xiao TS, Lan K, Yang J, Li H, Peng C, Qiu Z, Jentsch TJ, Xiao H. Transfer of cGAMP into Bystander Cells via LRRC8 Volume-Regulated Anion Channels Augments STING-Mediated Interferon Responses and Anti-viral Immunity. Immunity 2020; 52:767-781.e6. [PMID: 32277911 DOI: 10.1016/j.immuni.2020.03.016] [Citation(s) in RCA: 160] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/24/2020] [Accepted: 03/24/2020] [Indexed: 12/12/2022]
Abstract
The enzyme cyclic GMP-AMP synthase (cGAS) senses cytosolic DNA in infected and malignant cells and catalyzes the formation of 2'3'cGMP-AMP (cGAMP), which in turn triggers interferon (IFN) production via the STING pathway. Here, we examined the contribution of anion channels to cGAMP transfer and anti-viral defense. A candidate screen revealed that inhibition of volume-regulated anion channels (VRACs) increased propagation of the DNA virus HSV-1 but not the RNA virus VSV. Chemical blockade or genetic ablation of LRRC8A/SWELL1, a VRAC subunit, resulted in defective IFN responses to HSV-1. Biochemical and electrophysiological analyses revealed that LRRC8A/LRRC8E-containing VRACs transport cGAMP and cyclic dinucleotides across the plasma membrane. Enhancing VRAC activity by hypotonic cell swelling, cisplatin, GTPγS, or the cytokines TNF or interleukin-1 increased STING-dependent IFN response to extracellular but not intracellular cGAMP. Lrrc8e-/- mice exhibited impaired IFN responses and compromised immunity to HSV-1. Our findings suggest that cell-to-cell transmission of cGAMP via LRRC8/VRAC channels is central to effective anti-viral immunity.
Collapse
Affiliation(s)
- Chun Zhou
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, CAS Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xia Chen
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, CAS Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China; College of Life Sciences, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Rosa Planells-Cases
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin, D-13125 Berlin, Germany
| | - Jiachen Chu
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Li Wang
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, CAS Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Limin Cao
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, CAS Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhihong Li
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Science, Shanghai 201210, China; Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China
| | - Karen I López-Cayuqueo
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin, D-13125 Berlin, Germany
| | - Yadong Xie
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, CAS Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Shiwei Ye
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiang Wang
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Florian Ullrich
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin, D-13125 Berlin, Germany
| | - Shixin Ma
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, CAS Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yiyuan Fang
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiaoming Zhang
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhikang Qian
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiaozheng Liang
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Shi-Qing Cai
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhengfan Jiang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Dongming Zhou
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Qibin Leng
- Affiliated Cancer Hospital & Institute of Guangzhou Medical University, State Key Laboratory of Respiratory Diseases, Guangzhou Medical University, Guangzhou, Guangdong 510180, China
| | - Tsan S Xiao
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Ke Lan
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Jinbo Yang
- College of Life Sciences, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Huabin Li
- Center for Allergic and Inflammatory Diseases & Department of Otolaryngology, Head and Neck Surgery, Affiliated Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai 200031, China
| | - Chao Peng
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Science, Shanghai 201210, China; Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China
| | - Zhaozhu Qiu
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Thomas J Jentsch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin, D-13125 Berlin, Germany; NeuroCure Cluster of Excellence, Charité University Medicine, D-10117 Berlin, Germany.
| | - Hui Xiao
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, CAS Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
| |
Collapse
|