1
|
Battaglia M, Rossignol O, Lorenzo LE, Deguire J, Godin AG, D’Amato FR, De Koninck Y. Enhanced harm detection following maternal separation: Transgenerational transmission and reversibility by inhaled amiloride. SCIENCE ADVANCES 2023; 9:eadi8750. [PMID: 37792939 PMCID: PMC10550232 DOI: 10.1126/sciadv.adi8750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 09/01/2023] [Indexed: 10/06/2023]
Abstract
Early-life adversities are associated with altered defensive responses. Here, we demonstrate that the repeated cross-fostering (RCF) paradigm of early maternal separation is associated with enhancements of distinct homeostatic reactions: hyperventilation in response to hypercapnia and nociceptive sensitivity, among the first generation of RCF-exposed animals, as well as among two successive generations of their normally reared offspring, through matrilineal transmission. Parallel enhancements of acid-sensing ion channel 1 (ASIC1), ASIC2, and ASIC3 messenger RNA transcripts were detected transgenerationally in central neurons, in the medulla oblongata, and in periaqueductal gray matter of RCF-lineage animals. A single, nebulized dose of the ASIC-antagonist amiloride renormalized respiratory and nociceptive responsiveness across the entire RCF lineage. These findings reveal how, following an early-life adversity, a biological memory reducible to a molecular sensor unfolds, shaping adaptation mechanisms over three generations. Our findings are entwined with multiple correlates of human anxiety and pain conditions and suggest nebulized amiloride as a therapeutic avenue.
Collapse
Affiliation(s)
- Marco Battaglia
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Child Youth and Emerging Adult Programme, Centre for Addiction and Mental Health, Toronto, ON, Canada
- CERVO Brain Research Centre, Québec Mental Health Institute, Québec City, QC, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, QC, Canada
| | - Orlane Rossignol
- CERVO Brain Research Centre, Québec Mental Health Institute, Québec City, QC, Canada
| | - Louis-Etienne Lorenzo
- CERVO Brain Research Centre, Québec Mental Health Institute, Québec City, QC, Canada
| | - Jasmin Deguire
- CERVO Brain Research Centre, Québec Mental Health Institute, Québec City, QC, Canada
| | - Antoine G. Godin
- CERVO Brain Research Centre, Québec Mental Health Institute, Québec City, QC, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, QC, Canada
| | - Francesca R. D’Amato
- Institute of Biochemistry and Cell Biology, National Research Council, Rome, Italy
| | - Yves De Koninck
- CERVO Brain Research Centre, Québec Mental Health Institute, Québec City, QC, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, QC, Canada
| |
Collapse
|
2
|
Pissas KP, Schilling M, Tian Y, Gründer S. Functional characterization of acid-sensing ion channels in the cerebellum-originating medulloblastoma cell line DAOY and in cerebellar granule neurons. Pflugers Arch 2023; 475:1073-1087. [PMID: 37474775 PMCID: PMC10409673 DOI: 10.1007/s00424-023-02839-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 07/03/2023] [Accepted: 07/09/2023] [Indexed: 07/22/2023]
Abstract
Acid-sensing ion channels (ASICs) are Na+ channels that are almost ubiquitously expressed in neurons of the brain. Functional ASIC1a is also expressed in glioblastoma stem cells, where it might sense the acidic tumor microenvironment. Prolonged acidosis induces cell death in neurons and reduces tumor sphere formation in glioblastoma via activation of ASIC1a. It is currently unknown whether ASICs are expressed and involved in acid-induced cell death in other types of brain tumors. In this study, we investigated ASICs in medulloblastoma, using two established cell lines, DAOY and UW228, as in vitro models. In addition, we characterized ASICs in the most numerous neuron of the brain, the cerebellar granule cell, which shares the progenitor cell with some forms of medulloblastoma. We report compelling evidence using RT-qPCR, western blot and whole-cell patch clamp that DAOY and cerebellar granule cells, but not UW228 cells, functionally express homomeric ASIC1a. Additionally, Ca2+-imaging revealed that extracellular acidification elevated intracellular Ca2+-levels in DAOY cells independently of ASICs. Finally, we show that overexpression of RIPK3, a key component of the necroptosis pathway, renders DAOY cells susceptible to acid-induced cell death via activation of ASIC1a. Our data support the idea that ASIC1a is an important acid sensor in brain tumors and that its activation has potential to induce cell death in tumor cells.
Collapse
Affiliation(s)
| | - Maria Schilling
- Institute of Physiology, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Yuemin Tian
- Institute of Physiology, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Stefan Gründer
- Institute of Physiology, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany.
| |
Collapse
|
3
|
Díaz M, Pereda de Pablo D, Valdés‐Baizabal C, Santos G, Marin R. Molecular and biophysical features of hippocampal "lipid rafts aging" are modified by dietary n-3 long-chain polyunsaturated fatty acids. Aging Cell 2023; 22:e13867. [PMID: 37254617 PMCID: PMC10410061 DOI: 10.1111/acel.13867] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/25/2023] [Accepted: 04/29/2023] [Indexed: 06/01/2023] Open
Abstract
"Lipid raft aging" in nerve cells represents an early event in the development of aging-related neurodegenerative diseases, such as Alzheimer's disease. Lipid rafts are key elements in synaptic plasticity, and their modification with aging alters interactions and distribution of signaling molecules, such as glutamate receptors and ion channels involved in memory formation, eventually leading to cognitive decline. In the present study, we have analyzed, in vivo, the effects of dietary supplementation of n-3 LCPUFA on the lipid structure, membrane microviscosity, domain organization, and partitioning of ionotropic and metabotropic glutamate receptors in hippocampal lipid raffs in female mice. The results revealed several lipid signatures of "lipid rafts aging" in old mice fed control diets, consisting in depletion of n-3 LCPUFA, membrane unsaturation, along with increased levels of saturates, plasmalogens, and sterol esters, as well as altered lipid relevant indexes. These changes were paralleled by increased microviscosity and changes in the raft/non-raft (R/NR) distribution of AMPA-R and mGluR5. Administration of the n-3 LCPUFA diet caused the partial reversion of fatty acid alterations found in aged mice and returned membrane microviscosity to values found in young animals. Paralleling these findings, lipid rafts accumulated mGluR5, NMDA-R, and ASIC2, and increased their R/NR proportions, which collectively indicate changes in synaptic plasticity. Unexpectedly, this diet also modified the lipidome and dimension of lipid rafts, as well as the domain redistribution of glutamate receptors and acid-sensing ion channels involved in hippocampal synaptic plasticity, likely modulating functionality of lipid rafts in memory formation and reluctance to age-associated cognitive decline.
Collapse
Affiliation(s)
- Mario Díaz
- Department of Physics, Faculty of SciencesUniversity of La LagunaTenerifeSpain
- Instituto Universitario de Neurociencias (IUNE)TenerifeSpain
- Laboratory of Membrane Physiology and Biophysics, School of SciencesUniversity of La LagunaTenerifeSpain
| | - Daniel Pereda de Pablo
- Laboratory of Cellular NeurobiologyDepartment of Basic Medical Sciences, Faculty of Health SciencesUniversity of La LagunaTenerifeSpain
| | - Catalina Valdés‐Baizabal
- Laboratory of Cellular NeurobiologyDepartment of Basic Medical Sciences, Faculty of Health SciencesUniversity of La LagunaTenerifeSpain
| | - Guido Santos
- Department of Biochemistry, Microbiology, Cellular Biology and Genetics, School of SciencesUniversity of La LagunaTenerifeSpain
| | - Raquel Marin
- Laboratory of Cellular NeurobiologyDepartment of Basic Medical Sciences, Faculty of Health SciencesUniversity of La LagunaTenerifeSpain
- Associate Research Unit ULL‐CSIC “Membrane Physiology and Biophysics in Neurodegenerative and Cancer Diseases”TenerifeSpain
| |
Collapse
|
4
|
Fischer L, Schmidt A, Dopychai A, Joussen S, Joeres N, Oslender-Bujotzek A, Schmalzing G, Gründer S. Physiologically relevant acid-sensing ion channel (ASIC) 2a/3 heteromers have a 1:2 stoichiometry. Commun Biol 2023; 6:701. [PMID: 37422581 PMCID: PMC10329638 DOI: 10.1038/s42003-023-05087-4] [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: 09/12/2022] [Accepted: 06/29/2023] [Indexed: 07/10/2023] Open
Abstract
Acid-sensing ion channels (ASICs) sense extracellular protons and are involved in synaptic transmission and pain sensation. ASIC1a and ASIC3 are the ASIC subunits with the highest proton sensitivity. ASIC2a in contrast has low proton sensitivity but increases the variability of ASICs by forming heteromers with ASIC1a or ASIC3. ASICs are trimers and for the ASIC1a/2a heteromer it has been shown that subunits randomly assemble with a flexible 1:2/2:1 stoichiometry. Both heteromers have almost identical proton sensitivity intermediate between ASIC1a and ASIC2a. Here, we investigated the stoichiometry of the ASIC2a/3 heteromer. Using electrophysiology, we extensively characterized, first, cells expressing ASIC2a and ASIC3 at different ratios, second, concatemeric channels with a fixed subunit stoichiometry, and, third, channels containing loss-of-functions mutations in specific subunits. Our results conclusively show that only ASIC2a/3 heteromers with a 1:2 stoichiometry had a proton-sensitivity intermediate between ASIC2a and ASIC3. In contrast, the proton sensitivity of ASIC2a/3 heteromers with a 2:1 stoichiometry was strongly acid-shifted by more than one pH unit, which suggests that they are not physiologically relevant. Together, our results reveal that the proton sensitivity of the two ASIC2a/3 heteromers is clearly different and that ASIC3 and ASIC1a make remarkably different contributions to heteromers with ASIC2a.
Collapse
Affiliation(s)
- Leon Fischer
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074, Aachen, Germany
- Department of Anesthesiology, Technical University Dresden, Dresden, Germany
| | - Axel Schmidt
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074, Aachen, Germany
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, Bonn, Germany
| | - Anke Dopychai
- Institute of Clinical Pharmacology, RWTH Aachen University, Wendlingweg, D-52074, Aachen, Germany
| | - Sylvia Joussen
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074, Aachen, Germany
| | - Niko Joeres
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074, Aachen, Germany
- Department of Nephrology and Clinical Immunology, RWTH Aachen University, Pauwelsstrasse 30, D-52074, Aachen, Germany
| | | | - Günther Schmalzing
- Institute of Clinical Pharmacology, RWTH Aachen University, Wendlingweg, D-52074, Aachen, Germany
| | - Stefan Gründer
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074, Aachen, Germany.
| |
Collapse
|
5
|
Hung CH, Chin Y, Fong YO, Lee CH, Han DS, Lin JH, Sun WH, Chen CC. Acidosis-related pain and its receptors as targets for chronic pain. Pharmacol Ther 2023; 247:108444. [PMID: 37210007 DOI: 10.1016/j.pharmthera.2023.108444] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/24/2023] [Accepted: 05/15/2023] [Indexed: 05/22/2023]
Abstract
Sensing acidosis is an important somatosensory function in responses to ischemia, inflammation, and metabolic alteration. Accumulating evidence has shown that acidosis is an effective factor for pain induction and that many intractable chronic pain diseases are associated with acidosis signaling. Various receptors have been known to detect extracellular acidosis and all express in the somatosensory neurons, such as acid sensing ion channels (ASIC), transient receptor potential (TRP) channels and proton-sensing G-protein coupled receptors. In addition to sense noxious acidic stimulation, these proton-sensing receptors also play a vital role in pain processing. For example, ASICs and TRPs are involved in not only nociceptive activation but also anti-nociceptive effects as well as some other non-nociceptive pathways. Herein, we review recent progress in probing the roles of proton-sensing receptors in preclinical pain research and their clinical relevance. We also propose a new concept of sngception to address the specific somatosensory function of acid sensation. This review aims to connect these acid-sensing receptors with basic pain research and clinical pain diseases, thus helping with better understanding the acid-related pain pathogenesis and their potential therapeutic roles via the mechanism of acid-mediated antinociception.
Collapse
Affiliation(s)
- Chih-Hsien Hung
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yin Chin
- Department of Life Science & Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-On Fong
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Cheng-Han Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
| | - Der-Shen Han
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Bei-Hu Branch, Taipei, Taiwan
| | - Jiann-Her Lin
- Neuroscience Research Center, Taipei Medical University, Taipei, Taiwan; Department of Neurosurgery, Taipei Medical University Hospital, Taipei, Taiwan
| | - Wei-Hsin Sun
- Department of Life Science & Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chih-Cheng Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; Neuroscience Research Center, Taipei Medical University, Taipei, Taiwan; Neuroscience Program of Academia Sinica, Academia Sinica, Taipei, Taiwan.
| |
Collapse
|
6
|
Gladkikh IN, Klimovich AA, Kalina RS, Kozhevnikova YV, Khasanov TA, Osmakov DI, Koshelev SG, Monastyrnaya MM, Andreev YA, Leychenko EV, Kozlov SA. Anxiolytic, Analgesic and Anti-Inflammatory Effects of Peptides Hmg 1b-2 and Hmg 1b-4 from the Sea Anemone Heteractis magnifica. Toxins (Basel) 2023; 15:toxins15050341. [PMID: 37235375 DOI: 10.3390/toxins15050341] [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: 04/06/2023] [Revised: 05/05/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
Acid-sensing ion channels (ASICs) have been known as sensors of a local pH change within both physiological and pathological conditions. ASIC-targeting peptide toxins could be potent molecular tools for ASIC-manipulating in vitro, and for pathology treatment in animal test studies. Two sea anemone toxins, native Hmg 1b-2 and recombinant Hmg 1b-4, both related to APETx-like peptides, inhibited the transient current component of human ASIC3-Δ20 expressed in Xenopus laevis oocytes, but only Hmg 1b-2 inhibited the rat ASIC3 transient current. The Hmg 1b-4 action on rASIC3 as a potentiator was confirmed once again. Both peptides are non-toxic molecules for rodents. In open field and elevated plus maze tests, Hmg 1b-2 had more of an excitatory effect and Hmg 1b-4 had more of an anxiolytic effect on mouse behavior. The analgesic activity of peptides was similar and comparable to diclofenac activity in an acid-induced muscle pain model. In models of acute local inflammation induced by λ-carrageenan or complete Freund's adjuvant, Hmg 1b-4 had more pronounced and statistically significant anti-inflammatory effects than Hmg 1b-2. It exceeded the effect of diclofenac and, at a dose of 0.1 mg/kg, reduced the volume of the paw almost to the initial volume. Our data highlight the importance of a comprehensive study of novel ASIC-targeting ligands, and in particular, peptide toxins, and present the slightly different biological activity of the two similar toxins.
Collapse
Affiliation(s)
- Irina N Gladkikh
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok, Russia
| | - Anna A Klimovich
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok, Russia
| | - Rimma S Kalina
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok, Russia
| | - Yulia V Kozhevnikova
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok, Russia
| | - Timur A Khasanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Dmitry I Osmakov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Sergey G Koshelev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Margarita M Monastyrnaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok, Russia
| | - Yaroslav A Andreev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Elena V Leychenko
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok, Russia
| | - Sergey A Kozlov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| |
Collapse
|
7
|
Harmata GIS, Chan AC, Merfeld MJ, Taugher-Hebl RJ, Harijan AK, Hardie JB, Fan R, Long JD, Wang GZ, Dlouhy BJ, Bera AK, Narayanan NS, Wemmie JA. Intoxicating effects of alcohol depend on acid-sensing ion channels. Neuropsychopharmacology 2023; 48:806-815. [PMID: 36243771 PMCID: PMC10066229 DOI: 10.1038/s41386-022-01473-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/06/2022] [Accepted: 09/23/2022] [Indexed: 11/09/2022]
Abstract
Persons at risk for developing alcohol use disorder (AUD) differ in their sensitivity to acute alcohol intoxication. Alcohol effects are complex and thought to depend on multiple mechanisms. Here, we explored whether acid-sensing ion channels (ASICs) might play a role. We tested ASIC function in transfected CHO cells and amygdala principal neurons, and found alcohol potentiated currents mediated by ASIC1A homomeric channels, but not ASIC1A/2 A heteromeric channels. Supporting a role for ASIC1A in the intoxicating effects of alcohol in vivo, we observed marked alcohol-induced changes on local field potentials in basolateral amygdala, which differed significantly in Asic1a-/- mice, particularly in the gamma, delta, and theta frequency ranges. Altered electrophysiological responses to alcohol in mice lacking ASIC1A, were accompanied by changes in multiple behavioral measures. Alcohol administration during amygdala-dependent fear conditioning dramatically diminished context and cue-evoked memory on subsequent days after the alcohol had cleared. There was a significant alcohol by genotype interaction. Context- and cue-evoked memory were notably worse in Asic1a-/- mice. We further examined acute stimulating and sedating effects of alcohol on locomotor activity, loss of righting reflex, and in an acute intoxication severity scale. We found loss of ASIC1A increased the stimulating effects of alcohol and reduced the sedating effects compared to wild-type mice, despite similar blood alcohol levels. Together these observations suggest a novel role for ASIC1A in the acute intoxicating effects of alcohol in mice. They further suggest that ASICs might contribute to intoxicating effects of alcohol and AUD in humans.
Collapse
Affiliation(s)
- Gail I S Harmata
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa, USA
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Department of Neurosurgery, University of Iowa, Iowa City, IA, USA
- Pharmacological Sciences Predoctoral Research Training Program, Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
- Department of Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Aubrey C Chan
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa, USA
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Department of Veterans Affairs Medical Center, Iowa City, IA, USA
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Madison J Merfeld
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Department of Neurosurgery, University of Iowa, Iowa City, IA, USA
- Department of Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Rebecca J Taugher-Hebl
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Department of Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Anjit K Harijan
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - Jason B Hardie
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Department of Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Rong Fan
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Department of Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Jeffrey D Long
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
- Department of Biostatistics, University of Iowa, Iowa City, IA, USA
| | - Grace Z Wang
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Department of Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Brian J Dlouhy
- Department of Neurosurgery, University of Iowa, Iowa City, IA, USA
| | - Amal K Bera
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - Nandakumar S Narayanan
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Department of Neurology, University of Iowa, Iowa City, IA, USA
| | - John A Wemmie
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa, USA.
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA.
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA.
- Department of Neurosurgery, University of Iowa, Iowa City, IA, USA.
- Department of Veterans Affairs Medical Center, Iowa City, IA, USA.
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.
- Roy J. Carver Chair of Psychiatry and Neuroscience, University of Iowa, Iowa City, IA, USA.
| |
Collapse
|
8
|
Fuller MJ, Gupta SC, Fan R, Taugher-Hebl RJ, Wang GZ, Andrys NRR, Bera AK, Radley JJ, Wemmie JA. Investigating role of ASIC2 in synaptic and behavioral responses to drugs of abuse. Front Mol Biosci 2023; 10:1118754. [PMID: 36793786 PMCID: PMC9923001 DOI: 10.3389/fmolb.2023.1118754] [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: 12/07/2022] [Accepted: 01/19/2023] [Indexed: 01/31/2023] Open
Abstract
Drugs of abuse produce rearrangements at glutamatergic synapses thought to contribute to drug-reinforced behaviors. Acid-Sensing Ion Channels (ASICs) have been suggested to oppose these effects, largely due to observations in mice lacking the ASIC1A subunit. However, the ASIC2A and ASIC2B subunits are known to interact with ASIC1A, and their potential roles in drugs of abuse have not yet been investigated. Therefore, we tested the effects of disrupting ASIC2 subunits in mice exposed to drugs of abuse. We found conditioned place preference (CPP) to both cocaine and morphine were increased in Asic2 -/- mice, which is similar to what was observed in Asic1a -/- mice. Because nucleus accumbens core (NAcc) is an important site of ASIC1A action, we examined expression of ASIC2 subunits there. By western blot ASIC2A was readily detected in wild-type mice, while ASIC2B was not, suggesting ASIC2A is the predominant subunit in nucleus accumbens core. An adeno-associated virus vector (AAV) was used to drive recombinant ASIC2A expression in nucleus accumbens core of Asic2 -/- mice, resulting in near normal protein levels. Moreover, recombinant ASIC2A integrated with endogenous ASIC1A subunits to form functional channels in medium spiny neurons (MSNs). However, unlike ASIC1A, region-restricted restoration of ASIC2A in nucleus accumbens core was not sufficient to affect cocaine or morphine conditioned place preference, suggesting effects of ASIC2 differ from those of ASIC1A. Supporting this contrast, we found that AMPA receptor subunit composition and the ratio of AMPA receptor-mediated current to NMDA receptor-mediated current (AMPAR/NMDAR) were normal in Asic2 -/- mice and responded to cocaine withdrawal similarly to wild-type animals. However, disruption of ASIC2 significantly altered dendritic spine morphology, and these effects differed from those reported previously in mice lacking ASIC1A. We conclude that ASIC2 plays an important role in drug-reinforced behavior, and that its mechanisms of action may differ from ASIC1A.
Collapse
Affiliation(s)
- Margaret J. Fuller
- Department of Psychiatry, University of Iowa, Iowa City, IA, United States
- Department of Veterans Affairs Medical Center, Iowa City, IA, United States
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, United States
- Medical Scientist Training Program, University of Iowa, Iowa City, IA, United States
| | - Subhash C. Gupta
- Department of Psychiatry, University of Iowa, Iowa City, IA, United States
- Department of Veterans Affairs Medical Center, Iowa City, IA, United States
| | - Rong Fan
- Department of Psychiatry, University of Iowa, Iowa City, IA, United States
- Department of Veterans Affairs Medical Center, Iowa City, IA, United States
| | - Rebecca J. Taugher-Hebl
- Department of Psychiatry, University of Iowa, Iowa City, IA, United States
- Department of Veterans Affairs Medical Center, Iowa City, IA, United States
| | - Grace Z. Wang
- Department of Psychiatry, University of Iowa, Iowa City, IA, United States
- Department of Veterans Affairs Medical Center, Iowa City, IA, United States
| | - Noah R. R. Andrys
- Department of Psychiatry, University of Iowa, Iowa City, IA, United States
- Department of Veterans Affairs Medical Center, Iowa City, IA, United States
| | - Amal K. Bera
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - Jason J. Radley
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, United States
| | - John A. Wemmie
- Department of Psychiatry, University of Iowa, Iowa City, IA, United States
- Department of Veterans Affairs Medical Center, Iowa City, IA, United States
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, United States
- Medical Scientist Training Program, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, United States
- Department of Neurosurgery, University of Iowa, Iowa City, IA, United States
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA, United States
| |
Collapse
|
9
|
Cortés Franco KD, Brakmann IC, Feoktistova M, Panayotova-Dimitrova D, Gründer S, Tian Y. Aggressive migration in acidic pH of a glioblastoma cancer stem cell line in vitro is independent of ASIC and K Ca3.1 ion channels, but involves phosphoinositide 3-kinase. Pflugers Arch 2023; 475:405-416. [PMID: 36522586 PMCID: PMC9908655 DOI: 10.1007/s00424-022-02781-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022]
Abstract
The microenvironment of proliferative and aggressive tumours, such as the brain tumour glioblastoma multiforme (GBM), is often acidic, hypoxic, and nutrient deficient. Acid-sensing ion channels (ASICs) are proton-sensitive Na+ channels that have been proposed to play a role in pH sensing and in modulation of cancer cell migration. We previously reported that primary glioblastoma stem cells (GSCs), which grow as multicellular tumour spheroids, express functional ASIC1a and ASIC3, whereas ASIC2a is downregulated in GSCs. Using a 2.5D migration assay, here we report that acidic pH dramatically increased migration of GSCs of the pro-neural subtype. Pharmacological blockade as well as CRISPR-Cas9-mediated gene knock-out of ASIC1a or stable overexpression of ASIC2a, however, revealed that neither ASIC1a nor ASIC3, nor downregulation of ASIC2a, mediated the aggressive migration at acidic pH. Therefore, we tested the role of two other proteins previously implicated in cancer cell migration: the Ca2+-activated K+ channel KCa3.1 (KCNN4) and phosphoinositide 3-kinase (PI3K). While pharmacological blockade of KCa3.1 did also not affect migration, blockade of PI3K decreased migration at acidic pH to control levels. In summary, our study reveals a strongly enhanced migration of GSCs at acidic pH in vitro and identifies PI3K as an important mediator of this effect.
Collapse
Affiliation(s)
| | - Ilka C Brakmann
- Institute of Physiology, RWTH Aachen University, Pauwelsstraße 30, D-52074, Aachen, Germany
| | - Maria Feoktistova
- Department of Dermatology, RWTH Aachen University, Pauwelsstraße 30, D-52074, Aachen, Germany
| | | | - Stefan Gründer
- Institute of Physiology, RWTH Aachen University, Pauwelsstraße 30, D-52074, Aachen, Germany.
| | - Yuemin Tian
- Institute of Physiology, RWTH Aachen University, Pauwelsstraße 30, D-52074, Aachen, Germany
| |
Collapse
|
10
|
Zhigulin AS, Tikhonov DB, Barygin OI. Mechanisms of acid-sensing ion channels inhibition by nafamostat, sepimostat and diminazene. Eur J Pharmacol 2022; 938:175394. [PMID: 36403685 DOI: 10.1016/j.ejphar.2022.175394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 10/27/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022]
Abstract
Acid-sensing ion channels (ASICs) are blocked by many cationic compounds. Mechanisms of action, which may include pore block, modulation of activation and desensitization, need systematic analysis to allow predictable design of new potent and selective drugs. In this work, we studied the action of the serine protease inhibitors nafamostat, sepimostat, gabexate and camostat, on native ASICs in rat giant striatal interneurons and recombinant ASIC1a and ASIC2a channels, and compared it to that of well-known small molecule ASIC blocker diminazene. All these compounds have positively charged amidine and/or guanidine groups in their structure. Nafamostat, sepimostat and diminazene inhibited pH 6.5-induced currents in rat striatal interneurons at -80 mV holding voltage with IC50 values of 0.78 ± 0.12 μM, 2.4 ± 0.3 μM and 0.40 ± 0.09 μM, respectively, whereas camostat and gabexate were practically ineffective. The inhibition by nafamostat, sepimostat and diminazene was voltage-dependent evidencing binding in the channel pore. They were not trapped in the closed channels, suggesting "foot-in-the-door" mechanism of action. The inhibitory activity of nafamostat, sepimostat and diminazene was similar in experiments on native ASICs and recombinant ASIC1a channels, while all of them were drastically less active against ASIC2a channels. According to our molecular modeling, three active compounds bind in the channel pore between Glu 433 and Ala 444 in a similar way. In view of the relative safety of nafamostat for clinical use in humans, it can be considered as a potential candidate for the treatment of pathophysiological conditions linked to ASICs disfunction, including inflammatory pain and ischemic stroke.
Collapse
Affiliation(s)
- Arseniy S Zhigulin
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
| | - Denis B Tikhonov
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
| | - Oleg I Barygin
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia.
| |
Collapse
|
11
|
Dynamic Distribution of ASIC1a Channels and Other Proteins within Cells Detected through Fractionation. MEMBRANES 2022; 12:membranes12040389. [PMID: 35448360 PMCID: PMC9027401 DOI: 10.3390/membranes12040389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/21/2022] [Accepted: 03/25/2022] [Indexed: 02/06/2023]
Abstract
Proteins in eukaryotic cells reside in different cell compartments. Many studies require the specific localization of proteins and the detection of any dynamic changes in intracellular protein distribution. There are several methods available for this purpose that rely on the fractionation of the different cell compartments. Fractionation protocols have evolved since the first use of a centrifuge to isolate organelles. In this study, we described a simple method that involves the use of a tabletop centrifuge and different detergents to obtain cell fractions enriched in cytosolic (Cyt), plasma membrane (PM), membranous organelle (MO), and nuclear (Nu) proteins and identify the proteins in each fraction. This method serves to identify transmembrane proteins such as channel subunits as well as PM-embedded or weakly associated proteins. This protocol uses a minute amount of cell material and typical equipment present in laboratories, and it takes approximately 3 h. The process was validated using endogenous and exogenous proteins expressed in the HEK293T cell line that were targeted to each compartment. Using a specific stimulus as a trigger, we showed and quantified the shuttling of a protein channel (ASIC1a, acid sensing ion channel) from the MO fraction to the PM fraction and the shuttling of a kinase from a cytosolic location to a nuclear location.
Collapse
|
12
|
Sivils A, Yang F, Wang JQ, Chu XP. Acid-Sensing Ion Channel 2: Function and Modulation. MEMBRANES 2022; 12:membranes12020113. [PMID: 35207035 PMCID: PMC8880099 DOI: 10.3390/membranes12020113] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 01/08/2023]
Abstract
Acid-sensing ion channels (ASICs) have an important influence on human physiology and pathology. They are members of the degenerin/epithelial sodium channel family. Four genes encode at least six subunits, which combine to form a variety of homotrimers and heterotrimers. Of these, ASIC1a homotrimers and ASIC1a/2 heterotrimers are most widely expressed in the central nervous system (CNS). Investigations into the function of ASIC1a in the CNS have revealed a wealth of information, culminating in multiple contemporary reviews. The lesser-studied ASIC2 subunits are in need of examination. This review will focus on ASIC2 in health and disease, with discussions of its role in modulating ASIC function, synaptic targeting, cardiovascular responses, and pharmacology, while exploring evidence of its influence in pathologies such as ischemic brain injury, multiple sclerosis, epilepsy, migraines, drug addiction, etc. This information substantiates the ASIC2 protein as a potential therapeutic target for various neurological, psychological, and cerebrovascular diseases.
Collapse
Affiliation(s)
| | | | | | - Xiang-Ping Chu
- Correspondence: ; Tel.: +1-816-235-2248; Fax: +1-816-235-6517
| |
Collapse
|
13
|
Salinas Castellanos LC, Uchitel OD, Weissmann C. Signaling Pathways in Proton and Non-proton ASIC1a Activation. Front Cell Neurosci 2021; 15:735414. [PMID: 34675777 PMCID: PMC8523820 DOI: 10.3389/fncel.2021.735414] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/09/2021] [Indexed: 11/13/2022] Open
Abstract
Acid-sensing ion channels (ASICs) regulate synaptic activities and play important roles in neurodegenerative diseases as well as pain conditions. Classically, ASICs are described as transiently activated by a reduced pH, followed by desensitization; the activation allows sodium influx, and in the case of ASIC1a-composed channels, also calcium to some degree. Several factors are emerging and extensively analyzed as modulators, activating, inhibiting, and potentiating specific channel subunits. However, the signaling pathways triggered by channel activation are only starting to be revealed.The channel has been recently shown to be activated through a mechanism other than proton-mediated. Indeed, the large extracellular loop of these channels opens the possibility that other non-proton ligands might exist. One such molecule discovered was a toxin present in the Texas coral snake venom. The finding was associated with the activation of the channel at neutral pH via the toxin and causing intense and unremitting pain.By using different pharmacological tools, we analyzed the downstream signaling pathway triggered either by the proton and non-proton activation for human, mouse, and rat ASIC1a-composed channels in in vitro models. We show that for all species analyzed, the non-protonic mode of activation determines the activation of the ERK signaling cascade at a higher level and duration compared to the proton mode.This study adds to the growing evidence of the important role ASIC1a channels play in different physiological and pathological conditions and also hints at a possible pathological mechanism for a sustained effect.
Collapse
Affiliation(s)
| | | | - Carina Weissmann
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE—UBA CONICET), Facultad de Ciencias, Exactas y Naturales de la Universidad de Buenos Aires, Buenos Aires, Argentina
| |
Collapse
|
14
|
Zhu Y, Warrenfelt CIC, Flannery JC, Lindgren CA. Extracellular Protons Mediate Presynaptic Homeostatic Potentiation at the Mouse Neuromuscular Junction. Neuroscience 2021; 467:188-200. [PMID: 34215419 DOI: 10.1016/j.neuroscience.2021.01.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 01/22/2021] [Accepted: 01/28/2021] [Indexed: 01/27/2023]
Abstract
At the vertebrate neuromuscular junction (NMJ), presynaptic homeostatic potentiation (PHP) refers to the upregulation of neurotransmitter release via an increase in quantal content (QC) when the postsynaptic nicotinic acetylcholine receptors (nAChRs) are partially blocked. The mechanism of PHP has not been completely worked out. In particular, the identity of the presumed retrograde signal is still a mystery. We investigated the role of acid-sensing ion channels (ASICs) and extracellular protons in mediating PHP at the mouse NMJ. We found that blocking AISCs using benzamil, psalmotoxin-1 (PcTx1), or mambalgin-3 (Mamb3) prevented PHP. Likewise, extracellular acidification from pH 7.4 to 7.2 triggered a significant, reversable increase in QC and this increase could be prevented by PcTx1. Interestingly, an acidic saline (pH 7.2) also precluded the subsequent induction of PHP. Using immunofluorescence we observed ASIC2a and ASIC1 subunits at the NMJ. Our results indicate that protons and ASIC channels are involved in activating PHP at the mouse NMJ. We speculate that the partial blockade of nAChRs leads to a modest decrease in the pH of the synaptic cleft (∼0.2 pH units) and this activates ASIC channels on the presynaptic nerve terminal.
Collapse
Affiliation(s)
- Yiyang Zhu
- Department of Biology, Grinnell College, Grinnell, IA 50112, USA
| | | | - Jill C Flannery
- Department of Biology, Grinnell College, Grinnell, IA 50112, USA
| | - Clark A Lindgren
- Department of Biology, Grinnell College, Grinnell, IA 50112, USA.
| |
Collapse
|
15
|
Ruan N, Tribble J, Peterson AM, Jiang Q, Wang JQ, Chu XP. Acid-Sensing Ion Channels and Mechanosensation. Int J Mol Sci 2021; 22:ijms22094810. [PMID: 34062742 PMCID: PMC8125064 DOI: 10.3390/ijms22094810] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 12/16/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are mainly proton-gated cation channels that are activated by pH drops and nonproton ligands. They are part of the degenerin/epithelial sodium channel superfamily due to their sodium permeability. Predominantly expressed in the central nervous system, ASICs are involved in synaptic plasticity, learning/memory, and fear conditioning. These channels have also been implicated in multiple disease conditions, including ischemic brain injury, multiple sclerosis, Alzheimer’s disease, and drug addiction. Recent research has illustrated the involvement of ASICs in mechanosensation. Mechanosensation is a form of signal transduction in which mechanical forces are converted into neuronal signals. Specific mechanosensitive functions have been elucidated in functional ASIC1a, ASIC1b, ASIC2a, and ASIC3. The implications of mechanosensation in ASICs indicate their subsequent involvement in functions such as maintaining blood pressure, modulating the gastrointestinal function, and bladder micturition, and contributing to nociception. The underlying mechanism of ASIC mechanosensation is the tether-gate model, which uses a gating-spring mechanism to activate ASIC responses. Further understanding of the mechanism of ASICs will help in treatments for ASIC-related pathologies. Along with the well-known chemosensitive functions of ASICs, emerging evidence has revealed that mechanosensitive functions of ASICs are important for maintaining homeostasis and contribute to various disease conditions.
Collapse
|
16
|
Xu Y, Chen F. Factors and Molecular Mechanisms Influencing the Protein Synthesis, Degradation and Membrane Trafficking of ASIC1a. Front Cell Dev Biol 2020; 8:596304. [PMID: 33195276 PMCID: PMC7644914 DOI: 10.3389/fcell.2020.596304] [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: 08/19/2020] [Accepted: 10/05/2020] [Indexed: 12/31/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are members of the degenerin/epithelial sodium channel superfamily. They are extracellular pH sensors that are activated by protons. Among all ASICs, ASIC1a is one of the most intensively studied isoforms because of its unique ability to be permeable to Ca2+. In addition, it is considered to contribute to various pathophysiological conditions. As a membrane proton receptor, the number of ASIC1a present on the cell surface determines its physiological and pathological functions, and this number partially depends on protein synthesis, degradation, and membrane trafficking processes. Recently, several studies have shown that various factors affect these processes. Therefore, this review elucidated the major factors and underlying molecular mechanisms affecting ASIC1a protein expression and membrane trafficking.
Collapse
Affiliation(s)
- Yayun Xu
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, China.,The Key Laboratory of Major Autoimmune Diseases of Anhui Province, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China.,The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, China
| | - Feihu Chen
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, China.,The Key Laboratory of Major Autoimmune Diseases of Anhui Province, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China.,The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, China
| |
Collapse
|
17
|
Histidine Residues Are Responsible for Bidirectional Effects of Zinc on Acid-Sensing Ion Channel 1a/3 Heteromeric Channels. Biomolecules 2020; 10:biom10091264. [PMID: 32887365 PMCID: PMC7565092 DOI: 10.3390/biom10091264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/26/2020] [Accepted: 08/31/2020] [Indexed: 12/16/2022] Open
Abstract
Acid-sensing ion channel (ASIC) subunits 1a and 3 are highly expressed in central and peripheral sensory neurons, respectively. Endogenous biomolecule zinc plays a critical role in physiological and pathophysiological conditions. Here, we found that currents recorded from heterologously expressed ASIC1a/3 channels using the whole-cell patch-clamp technique were regulated by zinc with dual effects. Co-application of zinc dose-dependently potentiated both peak amplitude and the sustained component of heteromeric ASIC1a/3 currents; pretreatment with zinc between 3 to 100 µM exerted the same potentiation as co-application. However, pretreatment with zinc induced a significant inhibition of heteromeric ASIC1a/3 channels when zinc concentrations were over 250 µM. The potentiation of heteromeric ASIC1a/3 channels by zinc was pH dependent, as zinc shifted the pH dependence of ASIC1a/3 currents from a pH50 of 6.54 to 6.77; whereas the inhibition of ASIC1a/3 currents by zinc was also pH dependent. Furthermore, we systematically mutated histidine residues in the extracellular domain of ASIC1a or ASIC3 and found that histidine residues 72 and 73 in both ASIC1a and ASIC3, and histidine residue 83 in the ASIC3 were responsible for bidirectional effects on heteromeric ASIC1a/3 channels by zinc. These findings suggest that histidine residues in the extracellular domain of heteromeric ASIC1a/3 channels are critical for zinc-mediated effects.
Collapse
|
18
|
Osmakov DI, Khasanov TA, Andreev YA, Lyukmanova EN, Kozlov SA. Animal, Herb, and Microbial Toxins for Structural and Pharmacological Study of Acid-Sensing Ion Channels. Front Pharmacol 2020; 11:991. [PMID: 32733241 PMCID: PMC7360831 DOI: 10.3389/fphar.2020.00991] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/19/2020] [Indexed: 12/22/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are of the most sensitive molecular sensors of extracellular pH change in mammals. Six isoforms of these channels are widely represented in membranes of neuronal and non-neuronal cells, where these molecules are involved in different important regulatory functions, such as synaptic plasticity, learning, memory, and nociception, as well as in various pathological states. Structural and functional studies of both wild-type and mutant ASICs are essential for human care and medicine for the efficient treatment of socially significant diseases and ensure a comfortable standard of life. Ligands of ASICs serve as indispensable tools for these studies. Such bioactive compounds can be synthesized artificially. However, to date, the search for such molecules has been most effective amongst natural sources, such as animal venoms or plants and microbial extracts. In this review, we provide a detailed and comprehensive structural and functional description of natural compounds acting on ASICs, as well as the latest information on structural aspects of their interaction with the channels. Many of the examples provided in the review demonstrate the undoubted fundamental and practical successes of using natural toxins. Without toxins, it would not be possible to obtain data on the mechanisms of ASICs' functioning, provide detailed study of their pharmacological properties, or assess the contribution of the channels to development of different pathologies. The selectivity to different isoforms and variety in the channel modulation mode allow for the appraisal of prospective candidates for the development of new drugs.
Collapse
Affiliation(s)
- Dmitry I. Osmakov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Timur A. Khasanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
| | - Yaroslav A. Andreev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Ekaterina N. Lyukmanova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
| | - Sergey A. Kozlov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
| |
Collapse
|
19
|
Acid-Sensing Ion Channels Contribute to Type III Adenylyl Cyclase-Independent Acid Sensing of Mouse Olfactory Sensory Neurons. Mol Neurobiol 2020; 57:3042-3056. [PMID: 32458389 DOI: 10.1007/s12035-020-01943-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 05/13/2020] [Indexed: 10/24/2022]
Abstract
Acids can disturb the ecosystem of wild animals through altering their olfaction and olfaction-related survival behaviors. It is known that the main olfactory epithelia (MOE) of mammals rely on odorant receptors and type III adenylyl cyclase (AC3) to detect general odorants. However, it is unknown how the olfactory system sense protons or acidic odorants. Here, we show that while the MOE of AC3 knockout (KO) mice failed to respond to an odor mix in electro-olfactogram (EOG) recordings, it retained a small fraction of acid-evoked EOG responses. The acetic acid-induced EOG responses in wild-type (WT) MOE can be dissected into two components: the big component dependent on the AC3-mediated cAMP pathway and the much smaller component not. The small acid-evoked EOG response of the AC3 KOs was blocked by diminazene, an inhibitor of acid-sensing ion channels (ASICs), but not by forskolin/IBMX that desensitize the cAMP pathway. AC3 KO mice lost their sensitivity to detect pungent odorants but maintained sniffing behavior to acetic acid. Immunofluorescence staining demonstrated that ASIC1 proteins were highly expressed in olfactory sensory neurons (OSNs), mostly enriched in the knobs, dendrites, and somata, but not in olfactory cilia. Real-time polymerase chain reaction further detected the mRNA expression of ASIC1a, ASIC2b, and ASIC3 in the MOE. Additionally, mice exhibited reduced preference to attractive objects when placed in an environment with acidic volatiles. Together, we conclude that the mouse olfactory system has a non-conventional, likely ASIC-mediated ionotropic mechanism for acid sensing.
Collapse
|
20
|
APETx-Like Peptides from the Sea Anemone Heteractis crispa, Diverse in Their Effect on ASIC1a and ASIC3 Ion Channels. Toxins (Basel) 2020; 12:toxins12040266. [PMID: 32326130 PMCID: PMC7232172 DOI: 10.3390/toxins12040266] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/17/2020] [Accepted: 04/18/2020] [Indexed: 12/23/2022] Open
Abstract
Currently, five peptide modulators of acid-sensing ion channels (ASICs) attributed to structural class 1b of sea anemone toxins have been described. The APETx2 toxin is the first and most potent ASIC3 inhibitor, so its homologs from sea anemones are known as the APETx-like peptides. We have discovered that two APETx-like peptides from the sea anemone Heteractis crispa, Hcr 1b-3 and Hcr 1b-4, demonstrate different effects on rASIC1a and rASIC3 currents. While Hcr 1b-3 inhibits both investigated ASIC subtypes with IC50 4.95 ± 0.19 μM for rASIC1a and 17 ± 5.8 μM for rASIC3, Hcr 1b-4 has been found to be the first potentiator of ASIC3, simultaneously inhibiting rASIC1a at similar concentrations: EC50 1.53 ± 0.07 μM and IC50 1.25 ± 0.04 μM. The closest homologs, APETx2, Hcr 1b-1, and Hcr 1b-2, previously demonstrated the ability to inhibit hASIC3 with IC50 63 nM, 5.5, and 15.9 μM, respectively, while Hcr 1b-2 also inhibited rASIC1a with IC50 4.8 ± 0.3 μM. Computer modeling allowed us to describe the peculiarities of Hcr 1b-2 and Hcr 1b-4 interfaces with the rASIC1a channel and the stabilization of the expanded acidic pocket resulting from peptides binding which traps the rASIC1a channel in the closed state.
Collapse
|
21
|
Bencheva LI, De Matteo M, Ferrante L, Ferrara M, Prandi A, Randazzo P, Ronzoni S, Sinisi R, Seneci P, Summa V, Gallo M, Veneziano M, Cellucci A, Mazzocchi N, Menegon A, Di Fabio R. Identification of Isoform 2 Acid-Sensing Ion Channel Inhibitors as Tool Compounds for Target Validation Studies in CNS. ACS Med Chem Lett 2019; 10:627-632. [PMID: 30996808 DOI: 10.1021/acsmedchemlett.8b00591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/07/2019] [Indexed: 01/21/2023] Open
Abstract
Acid-sensing ion channels (ASICs) are a family of ion channels permeable to cations and largely responsible for the onset of acid-evoked ion currents both in neurons and in different types of cancer cells, thus representing a potential target for drug discovery. Owing to the limited attention ASIC2 has received so far, an exploratory program was initiated to identify ASIC2 inhibitors using diminazene, a known pan-ASIC inhibitor, as a chemical starting point for structural elaboration. The performed exploration enabled the identification of a novel series of ASIC2 inhibitors. In particular, compound 2u is a brain penetrant ASIC2 inhibitor endowed with an optimal pharmacokinetic profile. This compound may represent a useful tool to validate in animal models in vivo the role of ASIC2 in different neurodegenerative central nervous system pathologies.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Pierfausto Seneci
- Promidis, Via Olgettina 60, 20132 Milan, Italy
- Chemistry Department, Università degli Studi di Milano, Via Golgi 19, I-20133 Milan, Italy
| | - Vincenzo Summa
- IRBM Science Park, Via Pontina Km 30.600, 00070 Pomezia, Rome, Italy
| | - Mariana Gallo
- IRBM Science Park, Via Pontina Km 30.600, 00070 Pomezia, Rome, Italy
| | - Maria Veneziano
- IRBM Science Park, Via Pontina Km 30.600, 00070 Pomezia, Rome, Italy
| | | | - Nausicaa Mazzocchi
- San Raffaele Scientific Institute, Experimental Imaging Center, ALEMBIC, Advanced Light and Electron Microscopy BioImaging Center, Via Olgettina 60, 20132 Milan, Italy
| | - Andrea Menegon
- San Raffaele Scientific Institute, Experimental Imaging Center, ALEMBIC, Advanced Light and Electron Microscopy BioImaging Center, Via Olgettina 60, 20132 Milan, Italy
| | - Romano Di Fabio
- Promidis, Via Olgettina 60, 20132 Milan, Italy
- IRBM Science Park, Via Pontina Km 30.600, 00070 Pomezia, Rome, Italy
| |
Collapse
|
22
|
Membrane potential changes occurring upon acidification influence the binding of small-molecule inhibitors to ASIC1a. Neuropharmacology 2019; 148:366-376. [DOI: 10.1016/j.neuropharm.2019.01.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/10/2019] [Accepted: 01/31/2019] [Indexed: 12/23/2022]
|
23
|
Ma CL, Sun H, Yang L, Wang XT, Gao S, Chen XW, Ma ZY, Wang GH, Shi Z, Zheng QY. Acid-Sensing Ion Channel 1a Modulates NMDA Receptor Function Through Targeting NR1/NR2A/NR2B Triheteromeric Receptors. Neuroscience 2019; 406:389-404. [PMID: 30926548 DOI: 10.1016/j.neuroscience.2019.03.044] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/18/2019] [Accepted: 03/19/2019] [Indexed: 02/02/2023]
Abstract
The over-activation of N-methyl-D-aspartate receptors (NMDARs) is the main cause of neuronal death in brain ischemia. Both the NMDAR and the Acid-sensing ion channel 1a (ASIC1a) are present in the postsynaptic membrane of the central nervous system (CNS) and participate in physiological and pathological processes. However, the specific role played by ASIC1a in these processes remains elusive. We hypothesize that NMDARs are the primary mediators of normal synaptic transmission and excitatory neuronal death, while ASIC1a plays a modulatory role in facilitating NMDAR function. Using various experimental approaches including patch-clamp recordings on hippocampal slices and CHO cells, primary cultures of hippocampal neurons, calcium imaging, Western blot, cDNA transfection studies, and transient middle cerebral artery occlusion (tMCAO) mouse models, we demonstrate that stimulation of ASIC1a facilitates NMDAR function and inhibition of ASIC1a suppresses NMDAR over-activation. One of our key findings is that activation of ASIC1a selectively facilitates the NR1/NR2A/NR2B triheteromeric subtype of NMDAR currents. In accordance, inhibition of ASIC1a profoundly reduced the NMDAR-mediated EPSCs in older mouse brains, which are known to express much higher levels of triheteromeric NMDARs than younger brains. Furthermore, brain infarct sizes were reduced by a greater degree in older mice compared to younger ones when ASIC1a activity was suppressed. These data suggest that ASIC1a activity selectively enhances the function of triheteromeric NMDARs and exacerbates ischemic neuronal death especially in older animal brains. We propose ASIC1a as a novel therapeutic target for preventing and reducing the detrimental effect of brain ischemia in humans.
Collapse
Affiliation(s)
- Chun-Lei Ma
- Department of Physiology, Binzhou Medical University, Yantai Campus, 346 Guanhai Road, Laishan District, Yantai, Shandong, China.
| | - Hui Sun
- Department of Physiology, Binzhou Medical University, Yantai Campus, 346 Guanhai Road, Laishan District, Yantai, Shandong, China
| | - Liu Yang
- Department of Physiology, Binzhou Medical University, Yantai Campus, 346 Guanhai Road, Laishan District, Yantai, Shandong, China
| | - Xing-Tao Wang
- Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China
| | - Su Gao
- Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China
| | - Xiao-Wen Chen
- Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China
| | - Zhi-Yuan Ma
- School of Public Economics and Administration, Shanghai Finance and Economics University, Shanghai, China
| | - Gui-Hua Wang
- Department of Physiology, Binzhou Medical University, Yantai Campus, 346 Guanhai Road, Laishan District, Yantai, Shandong, China
| | - Zhen Shi
- Department of Physiology, Binzhou Medical University, Yantai Campus, 346 Guanhai Road, Laishan District, Yantai, Shandong, China
| | - Qing-Yin Zheng
- Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China
| |
Collapse
|
24
|
Fazia T, Pastorino R, Notartomaso S, Busceti C, Imbriglio T, Cannella M, Gentilini D, Morani G, Ticca A, Bitti P, Berzuini C, Dalmay T, Battaglia G, Bernardinelli L. Acid sensing ion channel 2: A new potential player in the pathophysiology of multiple sclerosis. Eur J Neurosci 2019; 49:1233-1243. [PMID: 30549327 PMCID: PMC6618268 DOI: 10.1111/ejn.14302] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 11/12/2018] [Accepted: 11/23/2018] [Indexed: 12/20/2022]
Abstract
Acid‐sensing ion channels (ASICs) are proton‐gated channels involved in multiple biological functions such as: pain modulation, mechanosensation, neurotransmission, and neurodegeneration. Earlier, we described the genetic association, within the Nuoro population, between Multiple Sclerosis (MS) and rs28936, located in ASIC2 3′UTR. Here we investigated the potential involvement of ASIC2 in MS inflammatory process. We induced experimental autoimmune encephalomyelitis (EAE) in wild‐type (WT), knockout Asic1−/− and Asic2−/− mice and observed a significant reduction of clinical score in Asic1−/− mice and a significant reduction in the clinical score in Asic2−/− mice in a limited time window (i.e., at days 20–23 after immunization). Immunohistochemistry confirmed the reduction in adaptive immune cell infiltrates in the spinal cord of EAE Asic1−/− mice. Analysis of mechanical allodynia, showed a significant higher pain threshold in Asic2−/− mice under physiological conditions, before immunization, as compared to WT mice and Asic1−/−. A significant reduction in pain threshold was observed in all three strains of mice after immunization. More importantly, analysis of human autoptic brain tissue in MS and control samples showed an increase of ASIC2 mRNA in MS samples. Subsequently, in vitro luciferase reporter gene assays, showed that ASIC2 expression is under possible miRNA regulation, in a rs28936 allele‐specific manner. Taken together, these findings suggest a potential role of ASIC2 in the pathophysiology of MS.
Collapse
Affiliation(s)
- Teresa Fazia
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Roberta Pastorino
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | | | | | - Tiziana Imbriglio
- I.R.C.C.S. Neuromed, Pozzilli, Italy.,Department of Physiology and Pharmacology, University Sapienza, Roma, Italy
| | | | - Davide Gentilini
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.,Unità di Bioinformatica e Statistica Genomica, Istituto Auxologico Italiano IRCCS, Cusano Milanino, Milano, Italy
| | - Gabriele Morani
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Anna Ticca
- Azienda Tutela Salute Sardegna, ASSL Nuoro, Neurologia e Stroke Unit, Ospedale "San Francesco", Nuoro, Italy
| | - Pierpaolo Bitti
- Azienda Tutela Salute Sardegna, ASSL Nuoro, Immunoematologia e Medicina Trasfusionale, Ospedale "San Francesco", Nuoro, Italy
| | - Carlo Berzuini
- Centre for Biostatistics, University of Manchester, Manchester, UK
| | - Tamas Dalmay
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | | | - Luisa Bernardinelli
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| |
Collapse
|
25
|
Soto E, Ortega-Ramírez A, Vega R. Protons as Messengers of Intercellular Communication in the Nervous System. Front Cell Neurosci 2018; 12:342. [PMID: 30364044 PMCID: PMC6191491 DOI: 10.3389/fncel.2018.00342] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/14/2018] [Indexed: 12/18/2022] Open
Abstract
In this review, evidence demonstrating that protons (H+) constitute a complex, regulated intercellular signaling mechanisms are presented. Given that pH is a strictly regulated variable in multicellular organisms, localized extracellular pH changes may constitute significant signals of cellular processes that occur in a cell or a group of cells. Several studies have demonstrated that the low pH of synaptic vesicles implies that neurotransmitter release is always accompanied by the co-release of H+ into the synaptic cleft, leading to transient extracellular pH shifts. Also, evidence has accumulated indicating that extracellular H+ concentration regulation is complex and implies a source of protons in a network of transporters, ion exchangers, and buffer capacity of the media that may finally establish the extracellular proton concentration. The activation of membrane transporters, increased production of CO2 and of metabolites, such as lactate, produce significant extracellular pH shifts in nano- and micro-domains in the central nervous system (CNS), constituting a reliable signal for intercellular communication. The acid sensing ion channels (ASIC) function as specific signal sensors of proton signaling mechanism, detecting subtle variations of extracellular H+ in a range varying from pH 5 to 8. The main question in relation to this signaling system is whether it is only synaptically restricted, or a volume modulator of neuron excitability. This signaling system may have evolved from a metabolic activity detection mechanism to a highly localized extracellular proton dependent communication mechanism. In this study, evidence showing the mechanisms of regulation of extracellular pH shifts and of the ASICs and its function in modulating the excitability in various systems is reviewed, including data and its role in synaptic neurotransmission, volume transmission and even segregated neurotransmission, leading to a reliable extracellular signaling mechanism.
Collapse
Affiliation(s)
- Enrique Soto
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | | | - Rosario Vega
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| |
Collapse
|
26
|
Dual actions of Psalmotoxin at ASIC1a and ASIC2a heteromeric channels (ASIC1a/2a). Sci Rep 2018; 8:7179. [PMID: 29739981 PMCID: PMC5940917 DOI: 10.1038/s41598-018-25386-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/20/2018] [Indexed: 02/06/2023] Open
Abstract
Acid-Sensing Ion Channels (ASICs) are gated by extracellular protons and play important roles in physiological and pathological states, such as pain and stroke. ASIC1a and ASIC2a, two of the most highly expressed subunits in the brain, form functional homo- and hetero-meric (ASIC1a/2a) channels. The function of ASIC1a has been widely studied using psalmotoxin (PcTx1), a venom-derived peptide, as an ASIC1a-selective antagonist. Here, using whole-cell patch clamp, we show that PcTx1 has dual actions at ASIC1a/2a. It can either inhibit or potentiate the heteromeric channel, depending on the conditioning and stimulating pHs. Potent inhibition occurs only at conditioning pHs that begin to desensitize the channel (IC50 = 2.9 nM at pH7.0, a threshold pH for desensitization of ASIC1a/2a). By contrast, potent potentiation can occur at the physiological pH in both CHO cells (EC50 = 56.1 nM) and cortical neurons (threshold concentration < 10 nM). PcTx1 potentiates ASIC1a/2a by increasing the apparent affinity of channel activation for protons. As such, potentiation is the strongest at moderate pHs, diminishing with increasing proton concentrations. Our findings identify PcTx1 as a valuable tool for studying ASIC1a/2a function and contribute significantly to the understanding of the diverse and complex pharmacology of PcTx1.
Collapse
|
27
|
Stephan G, Huang L, Tang Y, Vilotti S, Fabbretti E, Yu Y, Nörenberg W, Franke H, Gölöncsér F, Sperlágh B, Dopychai A, Hausmann R, Schmalzing G, Rubini P, Illes P. The ASIC3/P2X3 cognate receptor is a pain-relevant and ligand-gated cationic channel. Nat Commun 2018; 9:1354. [PMID: 29636447 PMCID: PMC5893604 DOI: 10.1038/s41467-018-03728-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 03/09/2018] [Indexed: 12/21/2022] Open
Abstract
Two subclasses of acid-sensing ion channels (ASIC3) and of ATP-sensitive P2X receptors (P2X3Rs) show a partially overlapping expression in sensory neurons. Here we report that both recombinant and native receptors interact with each other in multiple ways. Current measurements with the patch-clamp technique prove that ASIC3 stimulation strongly inhibits the P2X3R current partly by a Ca2+-dependent mechanism. The proton-binding site is critical for this effect and the two receptor channels appear to switch their ionic permeabilities during activation. Co-immunoprecipation proves the close association of the two protein structures. BN-PAGE and SDS-PAGE analysis is also best reconciled with the view that ASIC3 and P2X3Rs form a multiprotein structure. Finally, in vivo measurements in rats reveal the summation of pH and purinergically induced pain. In conclusion, the receptor subunits do not appear to form a heteromeric channel, but tightly associate with each other to form a protein complex, mediating unidirectional inhibition. Two subclasses of ligand-gated ion channels (ASIC3 and P2X3) are both present at sensory neurons and might be therefore subject to receptor crosstalk. Here authors use electrophysiology, biochemistry and co-immunoprecipitation to show that the two ion channels interact and affect P2X3 currents.
Collapse
Affiliation(s)
- Gabriele Stephan
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, University of Leipzig, Leipzig, 04107, Germany
| | - Lumei Huang
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, University of Leipzig, Leipzig, 04107, Germany.,Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
| | - Yong Tang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
| | - Sandra Vilotti
- Neurobiology Sector, International School for Advanced Studies, Trieste, 34136, Italy
| | - Elsa Fabbretti
- Department of Life Sciences, University of Trieste, Trieste, 34127, Italy
| | - Ye Yu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai, 100025, China
| | - Wolfgang Nörenberg
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, University of Leipzig, Leipzig, 04107, Germany
| | - Heike Franke
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, University of Leipzig, Leipzig, 04107, Germany
| | - Flóra Gölöncsér
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, 1043, Hungary.,János Szentágothai School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, 1043, Hungary
| | - Beáta Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, 1043, Hungary
| | - Anke Dopychai
- Molecular Pharmacology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, 52072, Germany
| | - Ralf Hausmann
- Molecular Pharmacology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, 52072, Germany
| | - Günther Schmalzing
- Molecular Pharmacology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, 52072, Germany
| | - Patrizia Rubini
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, University of Leipzig, Leipzig, 04107, Germany
| | - Peter Illes
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, University of Leipzig, Leipzig, 04107, Germany.
| |
Collapse
|
28
|
Xu Y, Jiang YQ, Li C, He M, Rusyniak WG, Annamdevula N, Ochoa J, Leavesley SJ, Xu J, Rich TC, Lin MT, Zha XM. Human ASIC1a mediates stronger acid-induced responses as compared with mouse ASIC1a. FASEB J 2018; 32:3832-3843. [PMID: 29447005 DOI: 10.1096/fj.201701367r] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Acid-sensing ion channels (ASICs) are the major proton receptor in the brain and a key mediator of acidosis-induced neuronal injuries in disease. Most of published data on ASIC function came from studies performed in mice, and relatively little is known about potential differences between human and mouse ASICs (hASIC and mASIC, respectively). This information is critical for us to better interpret the functional importance of ASICs in human disease. Here, we examined the expression of ASICs in acutely resected human cortical tissue. Compared with mouse cortex, human cortical tissue showed a similar ratio of ASIC1a:ASIC2a expression, had reduced ASIC2b level, and exhibited a higher membrane:total ratio of ASIC1a. We further investigated the mechanism for higher surface trafficking of hASIC1a in heterologous cells. A single amino acid at position 285 was critical for increased N-glycosylation and surface expression of hASIC1a. Consistent with the changes in trafficking and current, cells expressing hASIC1a or mASIC1a S285P mutant had a higher acid-activated calcium increase and exhibited worsened acidotoxicity. These data suggest that ASICs are likely to have a larger impact on acidosis-induced neuronal injuries in humans than mice, and this effect is, at least in part, a result of more efficient trafficking of hASIC1a.-Xu, Y., Jiang, Y.-Q., Li, C., He, M., Rusyniak, W. G., Annamdevula, N., Ochoa, J., Leavesley, S. J., Xu, J., Rich, T. C., Lin, M. T., Zha, X.-M. Human ASIC1a mediates stronger acid-induced responses as compared with mouse ASIC1a.
Collapse
Affiliation(s)
- Yuanyuan Xu
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Neuropharmacology and Drug Discovery, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Yu-Qing Jiang
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,The Third Hospital of Hebei Medical University, ShiJiaZhuang, China
| | - Ce Li
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Mindi He
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - W George Rusyniak
- Department of Neurosurgery, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Naga Annamdevula
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Juan Ochoa
- Department of Neurology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Silas J Leavesley
- Chemical and Biomolecular Engineering, College of Engineering, University of South Alabama, Mobile, Alabama, USA
| | - Jiangping Xu
- Department of Neuropharmacology and Drug Discovery, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Thomas C Rich
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Mike T Lin
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Xiang-Ming Zha
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| |
Collapse
|
29
|
Jiang YQ, Zha XM. miR-149 reduces while let-7 elevates ASIC1a expression in vitro. INTERNATIONAL JOURNAL OF PHYSIOLOGY, PATHOPHYSIOLOGY AND PHARMACOLOGY 2017; 9:147-152. [PMID: 29209451 PMCID: PMC5698691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 10/26/2017] [Indexed: 06/07/2023]
Abstract
Acid-sensing ion channel 1a (ASIC1a) is the key subunit that determines acid-activated currents in neurons. ASIC1a is important for neural plasticity, learning, and for multiple neurological diseases, including stroke, multiple sclerosis, and traumatic injuries. These findings underline the importance for better defining mechanisms that regulate ASIC1a expression. During the past decade, microRNA has emerged as one important group of regulatory molecules in controlling protein expression. However, little is known about whether microRNA regulates ASIC1a. Here, we assessed several microRNAs that have predicted targeting sequences in the 3' untranslated region (UTR) of mouse ASIC1a. Our results indicated that miR-144 and -149 reduced ASIC1a expression while Let-7 increased ASIC1a protein levels. miR-30c, -98, -125, -182* had no significant effect. Since a reduction in ASIC1a expression may have translational potentials in treating neuronal injury, we further asked whether the effect of miR-144 and miR-149, both reduced ASIC1a expression, was through specific targeting of the predicted sites on ASIC1a. We mutated the targeting sequence of miR-144 and miR-149 in ASIC1a UTR. The effect of miR-149 was abolished in the corresponding mutation. In contrast, miR-144 still reduced ASIC1a level when its predicted target sequence was mutated. This result indicates that miR-149 targets the 3'UTR of ASIC1a and reduces its expression.
Collapse
Affiliation(s)
- Yu-Qing Jiang
- Department of Physiology and Cell Biology, University of South Alabama College of MedicineMobile, AL 36688, USA
- The Third Hospital of Hebei Medical University139 Ziqiang Road, Shijiazhuang 050051, Hebei Province, China
| | - Xiang-Ming Zha
- Department of Physiology and Cell Biology, University of South Alabama College of MedicineMobile, AL 36688, USA
| |
Collapse
|
30
|
Mukhopadhyay M, Singh A, Sachchidanand S, Bera AK. Quercetin inhibits acid-sensing ion channels through a putative binding site in the central vestibular region. Neuroscience 2017; 348:264-272. [PMID: 28237818 DOI: 10.1016/j.neuroscience.2017.02.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 02/02/2017] [Accepted: 02/13/2017] [Indexed: 12/20/2022]
Abstract
Acid-sensing ion channels (ASICs) are associated with many pathophysiological processes, such as neuronal death during ischemic stroke, epileptic seizure and nociception. However, there is a dearth of ASIC-specific therapeutic blockers. Here we report that quercetin, a plant flavonoid, which is known for its neuroprotective effect, reversibly inhibits homomeric rat ASIC1a, ASIC2a and ASIC3 with an IC50 of about 2µM. Also, quercetin prevents low pH-induced intracellular calcium rise and cell death in HEK-293 cells, which have endogenous expression of ASIC1a and 2a. The inhibitory effect of quercetin on ASICs is not due to membrane perturbation, as it did not have any effect on other channels, like NMDA receptor, GABAA receptor and P2X4 receptor. Unlike quercetin, another flavonoid resveratrol had no effect on ASIC1a. Computational analysis revealed that quercetin binds to the channel in a cavity at the central vestibule, lined by several charged residues like Q276, R369, E373 and E416 in ASIC1a. Mutation of Arg369 to Ala or Glu416 to Gln abolished the inhibitory effect of quercetin on rat ASIC1a completely, while Glu373 to Gln showed reduced sensitivity. Our results raise the possibility of using quercetin for targeting ASICs in vivo.
Collapse
Affiliation(s)
- Mohona Mukhopadhyay
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences Building, Indian Institute of Technology Madras, Chennai 600036, India
| | - Anurag Singh
- National Institute of Pharmaceutical Education and Research (NIPER) Hajipur, Bihar, India
| | - S Sachchidanand
- National Institute of Pharmaceutical Education and Research (NIPER) Hajipur, Bihar, India
| | - Amal Kanti Bera
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences Building, Indian Institute of Technology Madras, Chennai 600036, India.
| |
Collapse
|
31
|
Jiang N, Wu J, Leng T, Yang T, Zhou Y, Jiang Q, Wang B, Hu Y, Ji YH, Simon RP, Chu XP, Xiong ZG, Zha XM. Region specific contribution of ASIC2 to acidosis-and ischemia-induced neuronal injury. J Cereb Blood Flow Metab 2017; 37:528-540. [PMID: 26861816 PMCID: PMC5381448 DOI: 10.1177/0271678x16630558] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Acidosis in the brain plays a critical role in neuronal injury in neurological diseases, including brain ischemia. One key mediator of acidosis-induced neuronal injury is the acid-sensing ion channels (ASICs). Current literature has focused on ASIC1a when studying acid signaling. The importance of ASIC2, which is also widely expressed in the brain, has not been appreciated. We found here a region-specific effect of ASIC2 on acid-mediated responses. Deleting ASIC2 reduced acid-activated current in cortical and striatal neurons, but had no significant effect in cerebellar granule neurons. In addition, we demonstrated that ASIC2 was important for ASIC1a expression, and that ASIC2a but not 2b facilitated ASIC1a surface trafficking in the brain. Further, we showed that ASIC2 deletion attenuated acidosis/ischemia-induced neuronal injury in organotypic hippocampal slices but had no effect in organotypic cerebellar slices. Consistent with an injurious role of ASIC2, we showed that ASIC2 deletion significantly protected the mouse brain from ischemic damage in vivo. These data suggest a critical region-specific contribution of ASIC2 to neuronal injury and reveal an important functional difference between ASIC2a and 2b in the brain.
Collapse
Affiliation(s)
- Nan Jiang
- 1 Department of Physiology and Cell Biology, University of South Alabama, Mobile, USA.,2 School of Life Sciences, Shanghai University, Shanghai, China
| | - Junjun Wu
- 1 Department of Physiology and Cell Biology, University of South Alabama, Mobile, USA.,3 China State Institute of Pharmaceutical Industry, Shanghai, China
| | - Tiandong Leng
- 4 Department of Neurobiology, Morehouse School of Medicine, Atlanta, USA
| | - Tao Yang
- 4 Department of Neurobiology, Morehouse School of Medicine, Atlanta, USA
| | - Yufan Zhou
- 1 Department of Physiology and Cell Biology, University of South Alabama, Mobile, USA
| | - Qian Jiang
- 5 Department of Basic Medical Science, University of Missouri-Kansas City, Kansas City, USA
| | - Bin Wang
- 6 Department of Mathematics and Statistics, University of South Alabama, Mobile, USA
| | - Youjia Hu
- 3 China State Institute of Pharmaceutical Industry, Shanghai, China
| | - Yong-Hua Ji
- 2 School of Life Sciences, Shanghai University, Shanghai, China
| | - Roger P Simon
- 4 Department of Neurobiology, Morehouse School of Medicine, Atlanta, USA
| | - Xiang-Ping Chu
- 5 Department of Basic Medical Science, University of Missouri-Kansas City, Kansas City, USA
| | - Zhi-Gang Xiong
- 4 Department of Neurobiology, Morehouse School of Medicine, Atlanta, USA
| | - Xiang-Ming Zha
- 1 Department of Physiology and Cell Biology, University of South Alabama, Mobile, USA
| |
Collapse
|
32
|
Kweon HJ, Cho JH, Jang IS, Suh BC. ASIC2a-dependent increase of ASIC3 surface expression enhances the sustained component of the currents. BMB Rep 2017; 49:542-547. [PMID: 27241858 PMCID: PMC5227295 DOI: 10.5483/bmbrep.2016.49.10.057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Indexed: 12/30/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are proton-gated cation channels widely expressed in the nervous system. Proton sensing by ASICs has been known to mediate pain, mechanosensation, taste transduction, learning and memory, and fear. In this study, we investigated the differential subcellular localization of ASIC2a and ASIC3 in heterologous expression systems. While ASIC2a targeted the cell surface itself, ASIC3 was mostly accumulated in the ER with partial expression in the plasma membrane. However, when ASIC3 was co-expressed with ASIC2a, its surface expression was markedly increased. By using bimolecular fluorescence complementation (BiFC) assay, we confirmed the heteromeric association between ASIC2a and ASIC3 subunits. In addition, we observed that the ASIC2a-dependent surface trafficking of ASIC3 remarkably enhanced the sustained component of the currents. Our study demonstrates that ASIC2a can increase the membrane conductance sensitivity to protons by facilitating the surface expression of ASIC3 through herteromeric assembly. [BMB Reports 2016; 49(10): 542-547].
Collapse
Affiliation(s)
- Hae-Jin Kweon
- Department of Brain & Cognitive Sciences, DGIST, Daegu 42988, Korea
| | - Jin-Hwa Cho
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea
| | - Il-Sung Jang
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea
| | - Byung-Chang Suh
- Department of Brain & Cognitive Sciences, DGIST, Daegu 42988, Korea
| |
Collapse
|
33
|
Acid-sensing ion channels are expressed in the ventrolateral medulla and contribute to central chemoreception. Sci Rep 2016; 6:38777. [PMID: 27934921 PMCID: PMC5146928 DOI: 10.1038/srep38777] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 11/14/2016] [Indexed: 12/30/2022] Open
Abstract
The role of acid-sensing ion channels (ASICs) in the ventrolateral medulla (VLM) remains uncertain. Here, we found that ASIC1a and ASIC2 are widely expressed in rat medulla, and the expression level is higher at neonatal stage as compared to adult stage. The two ASIC subunits co-localized in medualla neurons. Furthermore, pH reduction triggered typical ASIC-type currents in the medulla, including the VLM. These currents showed a pH50 value of 6.6 and were blocked by amiloride. Based on their sensitivity to psalmotoxin 1 (PcTx1) and zinc, homomeric ASIC1a and heteromeric ASIC1a/2 channels were likely responsible for acid-mediated currents in the mouse medulla. ASIC currents triggered by pH 5 disappeared in the VLM neurons from ASIC1−/−, but not ASIC2−/− mice. Activation of ASICs in the medulla also triggered neuronal excitation. Moreover, microinjection of artificial cerebrospinal fluid at a pH of 6.5 into the VLM increased integrated phrenic nerve discharge, inspiratory time and respiratory drive in rats. Both amiloride and PcTx1 inhibited the acid-induced stimulating effect on respiration. Collectively, our data suggest that ASICs are highly expressed in the medulla including the VLM, and activation of ASICs in the VLM contributes to central chemoreception.
Collapse
|
34
|
Storozhuk M, Kondratskaya E, Nikolaenko L, Krishtal O. A modulatory role of ASICs on GABAergic synapses in rat hippocampal cell cultures. Mol Brain 2016; 9:90. [PMID: 27760555 PMCID: PMC5070181 DOI: 10.1186/s13041-016-0269-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 10/05/2016] [Indexed: 12/27/2022] Open
Abstract
Rapid acidification occurring during synaptic vesicle release can activate acid-sensing ion channels (ASICs) both on pre- and postsynaptic neurons. In the latter case, a fraction of postsynaptic current would be mediated by cation-selective acid-sensing ion channels. Additionally, in both cases, activation of acid-sensing ion channels could modulate synaptic strength by affecting transmitter release and/or sensitivity of postsynaptic receptors. To address potential involvement of acid-sensing ion channels in mediation/modulation of synaptic transmission at hippocampal GABAergic synapses, we studied effects of three structurally different blockers of acid-sensing ion channels on evoked postsynaptic currents using the patch-clamp technique. We found that GABAergic postsynaptic currents, recorded below their reversal potential as inward currents, are suppressed by all the employed blockers of acid-sensing ion channels. These currents were suppressed by ~ 20 % in the presence of a novel blocker 5b (1 μM) and by ~30 % in the presence of either amiloride (25 μM) or diminazene (20 μM). In the same cells the suppression of postsynaptic currents, recorded above their reversal potential as outward currents was statistically insignificant. These results imply that the effects of blockers in our experiments are at least partially postsynaptic. On the other hand, in the case of mediation of a fraction of postsynaptic current by acid-sensing ion channels, an increase of outward currents would be expected under our experimental conditions. Our analysis of a bicuculline-resistant fraction of postsynaptic currents also suggests that effects of the blockers are predominantly modulatory. In this work we present evidence for the first time that acid-sensing ion channels play a functional role at hippocampal GABAergic synapses. The suppressing effect of the blockers of acid-sensing ion channels on GABAergic transmission is due, at least partially, to a postsynaptic but (predominantly) modulatory mechanism. We hypothesize that the modulatory effect is due to functional crosstalk between ASICs and GABAA-receptors recently reported in isolated neurons, however, verification of this hypothesis is necessary.
Collapse
Affiliation(s)
- Maksim Storozhuk
- Bogomoletz Institute of Physiology, Bogomoletz st. 4, Kiev, Ukraine. .,State Key Laboratory of Molecular and Cellular Biology, Bogomoletz st. 4, Kiev, Ukraine.
| | - Elena Kondratskaya
- Bogomoletz Institute of Physiology, Bogomoletz st. 4, Kiev, Ukraine.,State Key Laboratory of Molecular and Cellular Biology, Bogomoletz st. 4, Kiev, Ukraine
| | | | - Oleg Krishtal
- Bogomoletz Institute of Physiology, Bogomoletz st. 4, Kiev, Ukraine.,State Key Laboratory of Molecular and Cellular Biology, Bogomoletz st. 4, Kiev, Ukraine
| |
Collapse
|
35
|
Acid-Sensing Ion Channel 2a (ASIC2a) Promotes Surface Trafficking of ASIC2b via Heteromeric Assembly. Sci Rep 2016; 6:30684. [PMID: 27477936 PMCID: PMC4967927 DOI: 10.1038/srep30684] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/08/2016] [Indexed: 12/27/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are proton-activated cation channels that play important roles as typical proton sensors during pathophysiological conditions and normal synaptic activities. Among the ASIC subunits, ASIC2a and ASIC2b are alternative splicing products from the same gene, ACCN1. It has been shown that ASIC2 isoforms have differential subcellular distribution: ASIC2a targets the cell surface by itself, while ASIC2b resides in the ER. However, the underlying mechanism for this differential subcellular localization remained to be further elucidated. By constructing ASIC2 chimeras, we found that the first transmembrane (TM1) domain and the proximal post-TM1 domain (17 amino acids) of ASIC2a are critical for membrane targeting of the proteins. We also observed that replacement of corresponding residues in ASIC2b by those of ASIC2a conferred proton-sensitivity as well as surface expression to ASIC2b. We finally confirmed that ASIC2b is delivered to the cell surface from the ER by forming heteromers with ASIC2a, and that the N-terminal region of ASIC2a is additionally required for the ASIC2a-dependent membrane targeting of ASIC2b. Together, our study supports an important role of ASIC2a in membrane targeting of ASIC2b.
Collapse
|
36
|
Joeres N, Augustinowski K, Neuhof A, Assmann M, Gründer S. Functional and pharmacological characterization of two different ASIC1a/2a heteromers reveals their sensitivity to the spider toxin PcTx1. Sci Rep 2016; 6:27647. [PMID: 27277303 PMCID: PMC4899722 DOI: 10.1038/srep27647] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 05/24/2016] [Indexed: 12/23/2022] Open
Abstract
Acid Sensing Ion Channels (ASICs) detect extracellular proton signals and are involved in synaptic transmission and pain sensation. ASIC subunits assemble into homo- and heteromeric channels composed of three subunits. Single molecule imaging revealed that heteromers composed of ASIC1a and ASIC2a, which are widely expressed in the central nervous system, have a flexible 2:1/1:2 stoichiometry. It was hitherto not possible, however, to functionally differentiate these two heteromers. To have a homogenous population of ASIC1a/2a heteromers with either 2:1 or 1:2 stoichiometry, we covalently linked subunits in the desired configuration and characterized their functional properties in Xenopus oocytes. We show that the two heteromers have slightly different proton affinity, with an additional ASIC1a subunit increasing apparent affinity. Moreover, we found that zinc, which potentiates ASIC2a-containing ASICs but not homomeric ASIC1a, potentiates both heteromers. Finally, we show that PcTx1, which binds at subunit-subunit interfaces of homomeric ASIC1a, inhibits both heteromers suggesting that ASIC2a can also contribute to a PcTx1 binding site. Using this functional fingerprint, we show that rat cortical neurons predominantly express the ASIC1a/2a heteromer with a 2:1 stoichiometry. Collectively, our results reveal the contribution of individual subunits to the functional properties of ASIC1a/2a heteromers.
Collapse
Affiliation(s)
- Niko Joeres
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Katrin Augustinowski
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Andreas Neuhof
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Marc Assmann
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Stefan Gründer
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, D-52074 Aachen, Germany
| |
Collapse
|
37
|
Wu J, Leng T, Jing L, Jiang N, Chen D, Hu Y, Xiong ZG, Zha XM. Two di-leucine motifs regulate trafficking and function of mouse ASIC2a. Mol Brain 2016; 9:9. [PMID: 26819004 PMCID: PMC4729175 DOI: 10.1186/s13041-016-0190-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 01/21/2016] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Acid-sensing ion channels (ASICs) are proton-gated cation channels that mediate acid-induced responses in neurons. ASICs are important for mechanosensation, learning and memory, fear, pain, and neuronal injury. ASIC2a is widely expressed in the nervous system and modulates ASIC channel trafficking and activity in both central and peripheral systems. Here, to better understand mechanisms regulating ASIC2a, we searched for potential protein motifs that regulate ASIC2a trafficking. RESULTS AND CONCLUSIONS We identified a LLDLL sequence in the C-terminal juxtamembrane region of ASIC2a. Deleting or mutating the LLDLL sequence increased total expression and surface levels of ASIC2a in CHO cells. Mutating either of the two LL motifs had a similar effect. We further assessed ASIC2a localization in organotypic hippocampal slice neurons. The LL motif mutants exhibited increased dendritic trafficking and elevated targeting to dendritic spines. Consistent with an efficient trafficking, the LL motif mutants increased acid-activated current density. In addition, mutating the second LL motif increased pH sensitivity of the channel. These data identify the LL motifs as a negative regulator of ASIC2a trafficking and function, and suggest novel regulatory mechanisms in acid signaling.
Collapse
Affiliation(s)
- Junjun Wu
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, 5851 USA Dr N, MSB3074, Mobile, AL, 36688, USA. .,China State Institute of Pharmaceutical Industry, 285 Gebaini Road, Shanghai, 201203, China.
| | - Tiandong Leng
- Department of Neurobiology, Morehouse School of Medicine, 720 Westview Drive SW, Atlanta, 30310, GA, USA.
| | - Lan Jing
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, 5851 USA Dr N, MSB3074, Mobile, AL, 36688, USA. .,State Key Lab of New Drug & Pharmaceutical Process, Shanghai Institute of Pharmaceutical Industry, 1320 West Beijing Rd, Shanghai, 200040, China.
| | - Nan Jiang
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, 5851 USA Dr N, MSB3074, Mobile, AL, 36688, USA. .,Shanghai University School of Life Sciences, Shanghai, China.
| | - Daijie Chen
- China State Institute of Pharmaceutical Industry, 285 Gebaini Road, Shanghai, 201203, China.
| | - Youjia Hu
- China State Institute of Pharmaceutical Industry, 285 Gebaini Road, Shanghai, 201203, China.
| | - Zhi-Gang Xiong
- Department of Neurobiology, Morehouse School of Medicine, 720 Westview Drive SW, Atlanta, 30310, GA, USA.
| | - Xiang-ming Zha
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, 5851 USA Dr N, MSB3074, Mobile, AL, 36688, USA.
| |
Collapse
|