1
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Rangel-Sandoval C, Soula M, Li WP, Castillo PE, Hunt DL. NMDAR-mediated activation of pannexin1 channels contributes to the detonator properties of hippocampal mossy fiber synapses. iScience 2024; 27:109681. [PMID: 38680664 PMCID: PMC11046245 DOI: 10.1016/j.isci.2024.109681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 02/23/2024] [Accepted: 04/03/2024] [Indexed: 05/01/2024] Open
Abstract
Pannexins are large-pore ion channels expressed throughout the mammalian brain that participate in various neuropathologies; however, their physiological roles remain obscure. Here, we report that pannexin1 channels (Panx1) can be synaptically activated under physiological recording conditions in rodent acute hippocampal slices. Specifically, NMDA receptor (NMDAR)-mediated responses at the mossy fiber to CA3 pyramidal cell synapse were followed by a slow postsynaptic inward current that could activate CA3 pyramidal cells but was absent in Panx1 knockout mice. Immunoelectron microscopy revealed that Panx1 was localized near the postsynaptic density. Further, Panx1-mediated currents were potentiated by metabotropic receptors and bidirectionally modulated by burst-timing-dependent plasticity of NMDAR-mediated transmission. Lastly, Panx1 channels were preferentially recruited when NMDAR activation enters a supralinear regime, resulting in temporally delayed burst-firing. Thus, Panx1 can contribute to synaptic amplification and broadening the temporal associativity window for co-activated pyramidal cells, thereby supporting the auto-associative functions of the CA3 region.
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Affiliation(s)
- Cinthia Rangel-Sandoval
- Department of Neurosurgery, Department of Neurology, Department of Biomedical Sciences, Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Marisol Soula
- Dominick P. Purpura Department of Neuroscience, Department of Psychiatry and Behavioral Sciences. Albert Einstein College of Medicine, Bronx, NY, USA
| | - Wei-Ping Li
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA, USA
| | - Pablo E. Castillo
- Dominick P. Purpura Department of Neuroscience, Department of Psychiatry and Behavioral Sciences. Albert Einstein College of Medicine, Bronx, NY, USA
| | - David L. Hunt
- Department of Neurosurgery, Department of Neurology, Department of Biomedical Sciences, Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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2
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Obot P, Subah G, Schonwald A, Pan J, Velíšek L, Velíšková J, Stanton PK, Scemes E. Astrocyte and Neuronal Panx1 Support Long-Term Reference Memory in Mice. ASN Neuro 2023; 15:17590914231184712. [PMID: 37365910 DOI: 10.1177/17590914231184712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023] Open
Abstract
Pannexin 1 (Panx1) is an ubiquitously expressed protein that forms plasma membrane channels permeable to anions and moderate-sized signaling molecules (e.g., ATP, glutamate). In the nervous system, activation of Panx1 channels has been extensively shown to contribute to distinct neurological disorders (epilepsy, chronic pain, migraine, neuroAIDS, etc.), but knowledge of the extent to which these channels have a physiological role remains restricted to three studies supporting their involvement in hippocampus dependent learning. Given that Panx1 channels may provide an important mechanism for activity-dependent neuron-glia interaction, we used Panx1 transgenic mice with global and cell-type specific deletions of Panx1 to interrogate their participation in working and reference memory. Using the eight-arm radial maze, we show that long-term spatial reference memory, but not spatial working memory, is deficient in Panx1-null mice and that both astrocyte and neuronal Panx1 contribute to the consolidation of long-term spatial memory. Field potential recordings in hippocampal slices of Panx1-null mice revealed an attenuation of both long-term potentiation (LTP) of synaptic strength and long-term depression (LTD) at Schaffer collateral-CA1 synapses without alterations of basal synaptic transmission or pre-synaptic paired-pulse facilitation. Our results implicate both neuronal and astrocyte Panx1 channels as critical players for the development and maintenance of long-term spatial reference memory in mice.
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Affiliation(s)
- Price Obot
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
- Department of Emergency Medicine, Penn State Hershey Medical Center, Hershey, PA, USA
| | - Galadu Subah
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Antonia Schonwald
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Jian Pan
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Libor Velíšek
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
- Department of Pediatrics, Penn State Hershey Medical Center, Hershey, PA, USA
- Department of Neurology, New York Medical College, Valhalla, NY, USA
| | - Jana Velíšková
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
- Department of Obstetrics and Gynecology, New York Medical College, Valhalla, NY, USA
| | - Patric K Stanton
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
- Department of Neurology, New York Medical College, Valhalla, NY, USA
| | - Eliana Scemes
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
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3
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NMDA and P2X7 Receptors Require Pannexin 1 Activation to Initiate and Maintain Nociceptive Signaling in the Spinal Cord of Neuropathic Rats. Int J Mol Sci 2022; 23:ijms23126705. [PMID: 35743148 PMCID: PMC9223805 DOI: 10.3390/ijms23126705] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 02/01/2023] Open
Abstract
Pannexin 1 (Panx1) is involved in the spinal central sensitization process in rats with neuropathic pain, but its interaction with well-known, pain-related, ligand-dependent receptors, such as NMDA receptors (NMDAR) and P2X7 purinoceptors (P2X7R), remains largely unexplored. Here, we studied whether NMDAR- and P2X7R-dependent nociceptive signaling in neuropathic rats require the activation of Panx1 channels to generate spinal central sensitization, as assessed by behavioral (mechanical hyperalgesia) and electrophysiological (C-reflex wind-up potentiation) indexes. Administration of either a selective NMDAR agonist i.t. (NMDA, 2 mM) or a P2X7R agonist (BzATP, 150 μM) significantly increased both the mechanical hyperalgesia and the C-reflex wind-up potentiation, effects that were rapidly reversed (minutes) by i.t. administration of a selective pannexin 1 antagonist (10panx peptide, 300 μM), with the scores even reaching values of rats without neuropathy. Accordingly, 300 μM 10panx completely prevented the effects of NMDA and BzATP administered 1 h later, on mechanical hyperalgesia and C-reflex wind-up potentiation. Confocal immunofluorescence imaging revealed coexpression of Panx1 with NeuN protein in intrinsic dorsal horn neurons of neuropathic rats. The results indicate that both NMDAR- and P2X7R-mediated increases in mechanical hyperalgesia and C-reflex wind-up potentiation require neuronal Panx1 channel activation to initiate and maintain nociceptive signaling in neuropathic rats.
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4
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Activation of Cx43 Hemichannels Induces the Generation of Ca 2+ Oscillations in White Adipocytes and Stimulates Lipolysis. Int J Mol Sci 2021; 22:ijms22158095. [PMID: 34360859 PMCID: PMC8347185 DOI: 10.3390/ijms22158095] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 12/11/2022] Open
Abstract
The aim of the study was to investigate the mechanisms of Ca2+ oscillation generation upon activation of connexin-43 and regulation of the lipolysis/lipogenesis balance in white adipocytes through vesicular ATP release. With fluorescence microscopy it was revealed that a decrease in the concentration of extracellular calcium ([Ca2+]ex) results in two types of Ca2+ responses in white adipocytes: Ca2+ oscillations and transient Ca2+ signals. It was found that activation of the connexin half-channels is involved in the generation of Ca2+ oscillations, since the blockers of the connexin hemichannels-carbenoxolone, octanol, proadifen and Gap26-as well as Cx43 gene knockdown led to complete suppression of these signals. The activation of Cx43 in response to the reduction of [Ca2+]ex was confirmed by TIRF microscopy. It was shown that in response to the activation of Cx43, ATP-containing vesicles were released from the adipocytes. This process was suppressed by knockdown of the Cx43 gene and by bafilomycin A1, an inhibitor of vacuolar ATPase. At the level of intracellular signaling, the generation of Ca2+ oscillations in white adipocytes in response to a decrease in [Ca2+]ex occurred due to the mobilization of the Ca2+ ions from the thapsigargin-sensitive Ca2+ pool of IP3R as a result of activation of the purinergic P2Y1 receptors and phosphoinositide signaling pathway. After activation of Cx43 and generation of the Ca2+ oscillations, changes in the expression levels of key genes and their encoding proteins involved in the regulation of lipolysis were observed in white adipocytes. This effect was accompanied by a decrease in the number of adipocytes containing lipid droplets, while inhibition or knockdown of Cx43 led to inhibition of lipolysis and accumulation of lipid droplets. In this study, we investigated the mechanism of Ca2+ oscillation generation in white adipocytes in response to a decrease in the concentration of Ca2+ ions in the external environment and established an interplay between periodic Ca2+ modes and the regulation of the lipolysis/lipogenesis balance.
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5
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Boscia F, Elkjaer ML, Illes Z, Kukley M. Altered Expression of Ion Channels in White Matter Lesions of Progressive Multiple Sclerosis: What Do We Know About Their Function? Front Cell Neurosci 2021; 15:685703. [PMID: 34276310 PMCID: PMC8282214 DOI: 10.3389/fncel.2021.685703] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 05/23/2021] [Indexed: 12/19/2022] Open
Abstract
Despite significant advances in our understanding of the pathophysiology of multiple sclerosis (MS), knowledge about contribution of individual ion channels to axonal impairment and remyelination failure in progressive MS remains incomplete. Ion channel families play a fundamental role in maintaining white matter (WM) integrity and in regulating WM activities in axons, interstitial neurons, glia, and vascular cells. Recently, transcriptomic studies have considerably increased insight into the gene expression changes that occur in diverse WM lesions and the gene expression fingerprint of specific WM cells associated with secondary progressive MS. Here, we review the ion channel genes encoding K+, Ca2+, Na+, and Cl- channels; ryanodine receptors; TRP channels; and others that are significantly and uniquely dysregulated in active, chronic active, inactive, remyelinating WM lesions, and normal-appearing WM of secondary progressive MS brain, based on recently published bulk and single-nuclei RNA-sequencing datasets. We discuss the current state of knowledge about the corresponding ion channels and their implication in the MS brain or in experimental models of MS. This comprehensive review suggests that the intense upregulation of voltage-gated Na+ channel genes in WM lesions with ongoing tissue damage may reflect the imbalance of Na+ homeostasis that is observed in progressive MS brain, while the upregulation of a large number of voltage-gated K+ channel genes may be linked to a protective response to limit neuronal excitability. In addition, the altered chloride homeostasis, revealed by the significant downregulation of voltage-gated Cl- channels in MS lesions, may contribute to an altered inhibitory neurotransmission and increased excitability.
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Affiliation(s)
- Francesca Boscia
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples "Federico II", Naples, Italy
| | - Maria Louise Elkjaer
- Neurology Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Zsolt Illes
- Neurology Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Department of Neurology, Odense University Hospital, Odense, Denmark
| | - Maria Kukley
- Achucarro Basque Center for Neuroscience, Leioa, Spain.,Ikerbasque Basque Foundation for Science, Bilbao, Spain
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6
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O'Reilly C, Iavarone E, Yi J, Hill SL. Rodent somatosensory thalamocortical circuitry: Neurons, synapses, and connectivity. Neurosci Biobehav Rev 2021; 126:213-235. [PMID: 33766672 DOI: 10.1016/j.neubiorev.2021.03.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 02/15/2021] [Accepted: 03/14/2021] [Indexed: 01/21/2023]
Abstract
As our understanding of the thalamocortical system deepens, the questions we face become more complex. Their investigation requires the adoption of novel experimental approaches complemented with increasingly sophisticated computational modeling. In this review, we take stock of current data and knowledge about the circuitry of the somatosensory thalamocortical loop in rodents, discussing common principles across modalities and species whenever appropriate. We review the different levels of organization, including the cells, synapses, neuroanatomy, and network connectivity. We provide a complete overview of this system that should be accessible for newcomers to this field while nevertheless being comprehensive enough to serve as a reference for seasoned neuroscientists and computational modelers studying the thalamocortical system. We further highlight key gaps in data and knowledge that constitute pressing targets for future experimental work. Filling these gaps would provide invaluable information for systematically unveiling how this system supports behavioral and cognitive processes.
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Affiliation(s)
- Christian O'Reilly
- Azrieli Centre for Autism Research, Montreal Neurological Institute, McGill University, Montreal, Canada; Ronin Institute, Montclair, NJ, USA; Blue Brain Project, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland.
| | - Elisabetta Iavarone
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Jane Yi
- Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Sean L Hill
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland; Department of Psychiatry, University of Toronto, Toronto, Canada; Centre for Addiction and Mental Health, Toronto, Canada.
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7
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Purinergic signaling in nervous system health and disease: Focus on pannexin 1. Pharmacol Ther 2021; 225:107840. [PMID: 33753132 DOI: 10.1016/j.pharmthera.2021.107840] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2021] [Indexed: 02/06/2023]
Abstract
Purinergic signaling encompasses the cycle of adenosine 5' triphosphate (ATP) release and its metabolism into nucleotide and nucleoside derivatives, the direct release of nucleosides, and subsequent receptor-triggered downstream intracellular pathways. Since the discovery of nerve terminal and glial ATP release into the neuropil, purinergic signaling has been implicated in the modulation of nervous system development, function, and disease. In this review, we detail our current understanding of the roles of the pannexin 1 (PANX1) ATP-release channel in neuronal development and plasticity, glial signaling, and neuron-glial-immune interactions. We additionally provide an overview of PANX1 structure, activation, and permeability to orientate readers and highlight recent research developments. We identify areas of convergence between PANX1 and purinergic receptor actions. Additional highlights include data on PANX1's participation in the pathophysiology of nervous system developmental, degenerative, and inflammatory disorders. Our aim in combining this knowledge is to facilitate the movement of our current understanding of PANX1 in the context of other nervous system purinergic signaling mechanisms one step closer to clinical translation.
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8
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Insights into Potential Targets for Therapeutic Intervention in Epilepsy. Int J Mol Sci 2020; 21:ijms21228573. [PMID: 33202963 PMCID: PMC7697405 DOI: 10.3390/ijms21228573] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 02/06/2023] Open
Abstract
Epilepsy is a chronic brain disease that affects approximately 65 million people worldwide. However, despite the continuous development of antiepileptic drugs, over 30% patients with epilepsy progress to drug-resistant epilepsy. For this reason, it is a high priority objective in preclinical research to find novel therapeutic targets and to develop effective drugs that prevent or reverse the molecular mechanisms underlying epilepsy progression. Among these potential therapeutic targets, we highlight currently available information involving signaling pathways (Wnt/β-catenin, Mammalian Target of Rapamycin (mTOR) signaling and zinc signaling), enzymes (carbonic anhydrase), proteins (erythropoietin, copine 6 and complement system), channels (Transient Receptor Potential Vanilloid Type 1 (TRPV1) channel) and receptors (galanin and melatonin receptors). All of them have demonstrated a certain degree of efficacy not only in controlling seizures but also in displaying neuroprotective activity and in modifying the progression of epilepsy. Although some research with these specific targets has been done in relation with epilepsy, they have not been fully explored as potential therapeutic targets that could help address the unsolved issue of drug-resistant epilepsy and develop new antiseizure therapies for the treatment of epilepsy.
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9
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Pannexin 1 Regulates Network Ensembles and Dendritic Spine Development in Cortical Neurons. eNeuro 2019; 6:ENEURO.0503-18.2019. [PMID: 31118206 PMCID: PMC6557035 DOI: 10.1523/eneuro.0503-18.2019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 01/22/2023] Open
Abstract
Dendritic spines are the postsynaptic targets of excitatory synaptic inputs that undergo extensive proliferation and maturation during the first postnatal month in mice. However, our understanding of the molecular mechanisms that regulate spines during this critical period is limited. Previous work has shown that pannexin 1 (Panx1) regulates neurite growth and synaptic plasticity. We therefore investigated the impact of global Panx1 KO on spontaneous cortical neuron activity using Ca2+ imaging and in silico network analysis. Panx1 KO increased both the number and size of spontaneous co-active cortical neuron network ensembles. To understand the basis for these findings, we investigated Panx1 expression in postnatal synaptosome preparations from early postnatal mouse cortex. Between 2 and 4 postnatal weeks, we observed a precipitous drop in cortical synaptosome protein levels of Panx1, suggesting it regulates synapse proliferation and/or maturation. At the same time points, we observed significant enrichment of the excitatory postsynaptic density proteins PSD-95, GluA1, and GluN2a in cortical synaptosomes from global Panx1 knock-out mice. Ex vivo analysis of pyramidal neuron structure in somatosensory cortex revealed a consistent increase in dendritic spine densities in both male and female Panx1 KO mice. Similar findings were observed in an excitatory neuron-specific Panx1 KO line (Emx1-Cre driven; Panx1 cKOE) and in primary Panx1 KO cortical neurons cultured in vitro. Altogether, our study suggests that Panx1 negatively regulates cortical dendritic spine development.
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10
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Dahl G. The Pannexin1 membrane channel: distinct conformations and functions. FEBS Lett 2018; 592:3201-3209. [PMID: 29802622 DOI: 10.1002/1873-3468.13115] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 05/21/2018] [Indexed: 12/15/2022]
Abstract
The Pannexin1 (Panx1) membrane channel responds to different stimuli with distinct channel conformations. Most stimuli induce a large cation- and ATP-permeable conformation, hence Panx1 is involved in many physiological processes entailing purinergic signaling. For example, oxygen delivery in the peripheral circulatory system is regulated by ATP released from red blood cells and endothelial cells through Panx1 channels. The same membrane channel, however, when stimulated by positive membrane potential or by cleavage with caspase 3, is highly selective for the passage of chloride ions, excluding cations and ATP. Although biophysical data do not allow a distinction between the chloride-selective channels induced by voltage or by caspase cleavage, there must be other subtle differences in the structure, because overexpression of wtPanx1 is well tolerated by cells, while expression of the truncation mutant Panx1Δ378 results in slow cell death. Thus, in addition to the well-characterized two open conformations, there might be a third, more subtle conformational change involved in cell death.
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Affiliation(s)
- Gerhard Dahl
- Department of Physiology and Biophysics, University of Miami School of Medicine, FL, USA
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11
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Chiu YH, Schappe MS, Desai BN, Bayliss DA. Revisiting multimodal activation and channel properties of Pannexin 1. J Gen Physiol 2017; 150:19-39. [PMID: 29233884 PMCID: PMC5749114 DOI: 10.1085/jgp.201711888] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 11/09/2017] [Indexed: 12/23/2022] Open
Abstract
Pannexin 1 (Panx1) forms plasma membrane ion channels that are widely expressed throughout the body. Panx1 activation results in the release of nucleotides such as adenosine triphosphate and uridine triphosphate. Thus, these channels have been implicated in diverse physiological and pathological functions associated with purinergic signaling, such as apoptotic cell clearance, blood pressure regulation, neuropathic pain, and excitotoxicity. In light of this, substantial attention has been directed to understanding the mechanisms that regulate Panx1 channel expression and activation. Here we review accumulated evidence for the various activation mechanisms described for Panx1 channels and, where possible, the unitary channel properties associated with those forms of activation. We also emphasize current limitations in studying Panx1 channel function and propose potential directions to clarify the exciting and expanding roles of Panx1 channels.
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Affiliation(s)
- Yu-Hsin Chiu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
| | - Michael S Schappe
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
| | - Bimal N Desai
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
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12
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Zorzi V, Paciello F, Ziraldo G, Peres C, Mazzarda F, Nardin C, Pasquini M, Chiani F, Raspa M, Scavizzi F, Carrer A, Crispino G, Ciubotaru CD, Monyer H, Fetoni AR, M Salvatore A, Mammano F. Mouse Panx1 Is Dispensable for Hearing Acquisition and Auditory Function. Front Mol Neurosci 2017; 10:379. [PMID: 29234270 PMCID: PMC5712377 DOI: 10.3389/fnmol.2017.00379] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 10/30/2017] [Indexed: 11/13/2022] Open
Abstract
Panx1 forms plasma membrane channels in brain and several other organs, including the inner ear. Biophysical properties, activation mechanisms and modulators of Panx1 channels have been characterized in detail, however the impact of Panx1 on auditory function is unclear due to conflicts in published results. To address this issue, hearing performance and cochlear function of the Panx1−/− mouse strain, the first with a reported global ablation of Panx1, were scrutinized. Male and female homozygous (Panx1−/−), hemizygous (Panx1+/−) and their wild type (WT) siblings (Panx1+/+) were used for this study. Successful ablation of Panx1 was confirmed by RT-PCR and Western immunoblotting in the cochlea and brain of Panx1−/− mice. Furthermore, a previously validated Panx1-selective antibody revealed strong immunoreactivity in WT but not in Panx1−/− cochleae. Hearing sensitivity, outer hair cell-based “cochlear amplifier” and cochlear nerve function, analyzed by auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) recordings, were normal in Panx1+/− and Panx1−/− mice. In addition, we determined that global deletion of Panx1 impacts neither on connexin expression, nor on gap-junction coupling in the developing organ of Corti. Finally, spontaneous intercellular Ca2+ signal (ICS) activity in organotypic cochlear cultures, which is key to postnatal development of the organ of Corti and essential for hearing acquisition, was not affected by Panx1 ablation. Therefore, our results provide strong evidence that, in mice, Panx1 is dispensable for hearing acquisition and auditory function.
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Affiliation(s)
- Veronica Zorzi
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,School of Medicine, Institute of Otolaryngology, Catholic University, Rome, Italy
| | - Fabiola Paciello
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Gaia Ziraldo
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,School of Medicine, Institute of Otolaryngology, Catholic University, Rome, Italy
| | - Chiara Peres
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Flavia Mazzarda
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Science, Roma Tre University, Rome, Italy
| | - Chiara Nardin
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Science, Roma Tre University, Rome, Italy
| | - Miriam Pasquini
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, Rome, Italy
| | - Francesco Chiani
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Marcello Raspa
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | | | - Andrea Carrer
- Department of Physics and Astronomy G. Galilei, University of Padua, Padua, Italy
| | - Giulia Crispino
- Department of Physics and Astronomy G. Galilei, University of Padua, Padua, Italy
| | | | - Hannah Monyer
- Department of Clinical Neurobiology, Deutches Krebforschungzentrum, University of Heidelberg, Heidelberg, Germany
| | - Anna R Fetoni
- School of Medicine, Institute of Otolaryngology, Catholic University, Rome, Italy
| | - Anna M Salvatore
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Fabio Mammano
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Physics and Astronomy G. Galilei, University of Padua, Padua, Italy.,Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
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13
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Pannexin-1 channels in epilepsy. Neurosci Lett 2017; 695:71-75. [PMID: 28886985 DOI: 10.1016/j.neulet.2017.09.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 07/20/2017] [Accepted: 09/01/2017] [Indexed: 02/07/2023]
Abstract
Pannexin-1 (Panx1) expression is raised in several animal seizure models and in resected human epileptic brain tissue, suggesting relevance to epilepsy. Multiple factors that are characteristic of seizures are thought to regulate Panx1 channel opening, including elevated levels of extracellular K+. Panx1, when open, 1) releases ATP, glutamate, and other metabolites into the extracellular medium, and 2) may depolarize the membrane due to a channel reversal potential around 0mV. Resultant ATP release from stimulated Panx1 can activate purinergic receptors, including P2X7 receptors. Glutamate and other signaling molecules released by Panx1 opening may have both excitatory and inhibitory actions on seizure generation. This review examines the critical and complex roles of Panx1 channels in epilepsy, which could provide a basis for future therapeutics.
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14
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Scemes E, Velíšková J. Exciting and not so exciting roles of pannexins. Neurosci Lett 2017; 695:25-31. [PMID: 28284836 DOI: 10.1016/j.neulet.2017.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/02/2017] [Accepted: 03/06/2017] [Indexed: 01/24/2023]
Abstract
It is the current view that purinergic signaling regulates many physiological functions. Pannexin1 (Panx1), a member of the gap junction family of proteins is an ATP releasing channel that plays important physio-pathological roles in various tissues, including the CNS. Upon binding to purinergic receptors expressed in neural cells, ATP triggers cellular responses including increased cell proliferation, cell morphology changes, release of cytokines, and regulation of neuronal excitability via release of glutamate, GABA and ATP itself. Under pathological conditions such as ischemia, trauma, inflammation, and epilepsy, extracellular ATP concentrations increases drastically but the consequences of this surge is still difficult to characterize due to its rapid metabolism in ADP and adenosine, the latter having inhibitory action on neuronal activity. For seizures, for instance, the excitatory effect of ATP on neuronal activity is mainly related to its action of P2X receptors, while the inhibitory effects are related to activation of P1, adenosine receptors. Here we provide a mini review on the properties of pannexins with a main focus on Panx1 and its involvement in seizure activity. Although there are only few studies implicating Panx1 in seizures, they are illustrative of the dual role that Panx1 has on neuronal excitability.
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Affiliation(s)
- Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
| | - Jana Velíšková
- Departments of Cell Biology & Anatomy, Obstetrics & Gynecology and Neurology, New York Medical College, Valhalla, NY, 10595, USA.
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15
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Abstract
A central tenet in support of research reproducibility is the ability to uniquely identify research resources, i.e., reagents, tools, and materials that are used to perform experiments. However, current reporting practices for research resources are insufficient to identify the exact resources that are reported or to answer basic questions such as "How did other studies use resource X?" To address this issue, the Resource Identification Initiative was launched as a pilot project to improve the reporting standards for research resources in the methods sections of papers and thereby improve identifiability and scientific reproducibility. The pilot engaged over 25 biomedical journal editors from most major publishers, as well as scientists and funding officials. Authors were asked to include Research Resource Identifiers (RRIDs) in their manuscripts prior to publication for three resource types: antibodies, model organisms, and tools (i.e., software and databases). RRIDs are assigned by an authoritative database, for example a model organism database, for each type of resource. To make it easier for authors to obtain RRIDs, resources were aggregated from the appropriate databases and their RRIDs made available in a central web portal ( http://scicrunch.org/resources ). RRIDs meet three key criteria: they are machine readable, free to generate and access, and are consistent across publishers and journals. The pilot was launched in February of 2014 and over 300 papers have appeared that report RRIDs. The number of journals participating has expanded from the original 25 to more than 40 with RRIDs appearing in 62 different journals to date. Here, we present an overview of the pilot project and its outcomes to date. We show that authors are able to identify resources and are supportive of the goals of the project. Identifiability of the resources post-pilot showed a dramatic improvement for all three resource types, suggesting that the project has had a significant impact on identifiability of research resources.
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16
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Differential effects of pannexins on noise-induced hearing loss. Biochem J 2016; 473:4665-4680. [PMID: 27784763 DOI: 10.1042/bcj20160668] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/14/2016] [Accepted: 10/24/2016] [Indexed: 12/20/2022]
Abstract
Hearing loss, including noise-induced hearing loss, is highly prevalent and severely hinders an individual's quality of life, yet many of the mechanisms that cause hearing loss are unknown. The pannexin (Panx) channel proteins, Panx1 and Panx3, are regionally expressed in many cell types along the auditory pathway, and mice lacking Panx1 in specific cells of the inner ear exhibit hearing loss, suggesting a vital role for Panxs in hearing. We proposed that Panx1 and/or Panx3 null mice would exhibit severe hearing loss and increased susceptibility to noise-induced hearing loss. Using the auditory brainstem response, we surprisingly found that Panx1-/- and Panx3-/- mice did not harbor hearing or cochlear nerve deficits. Furthermore, while Panx1-/- mice displayed no protection against loud noise-induced hearing loss, Panx3-/- mice exhibited enhanced 16- and 24-kHz hearing recovery 7 days after a loud noise exposure (NE; 12 kHz tone, 115 dB sound pressure level, 1 h). Interestingly, Cx26, Cx30, Cx43, and Panx2 were up-regulated in Panx3-/- mice compared with wild-type and/or Panx1-/- mice, and assessment of the auditory tract revealed morphological changes in the middle ear bones of Panx3-/- mice. It is unclear if these changes alone are sufficient to provide protection against loud noise-induced hearing loss. Contrary to what we expected, these data suggest that Panx1 and Panx3 are not essential for baseline hearing in mice tested, but the therapeutic targeting of Panx3 may prove protective against mid-high-frequency hearing loss caused by loud NE.
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17
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Bandrowski A, Brush M, Grethe JS, Haendel MA, Kennedy DN, Hill S, Hof PR, Martone ME, Pols M, Tan SC, Washington N, Zudilova-Seinstra E, Vasilevsky N. The Resource Identification Initiative: A Cultural Shift in Publishing. J Comp Neurol 2016; 524:8-22. [PMID: 26599696 PMCID: PMC4684178 DOI: 10.1002/cne.23913] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 10/12/2015] [Indexed: 01/10/2023]
Abstract
A central tenet in support of research reproducibility is the ability to uniquely identify research resources, i.e., reagents, tools, and materials that are used to perform experiments. However, current reporting practices for research resources are insufficient to identify the exact resources that are reported or to answer basic questions such as “How did other studies use resource X?” To address this issue, the Resource Identification Initiative was launched as a pilot project to improve the reporting standards for research resources in the Methods sections of articles and thereby improve identifiability and scientific reproducibility. The pilot engaged over 25 biomedical journal editors from most major publishers, as well as scientists and funding officials. Authors were asked to include Research Resource Identifiers (RRIDs) in their articles prior to publication for three resource types: antibodies, model organisms, and tools (i.e., software and databases). RRIDs are assigned by an authoritative database, for example, a model organism database for each type of resource. To make it easier for authors to obtain RRIDs, resources were aggregated from the appropriate databases and their RRIDs made available in a central Web portal (http://scicrunch.org/resources). RRIDs meet three key criteria: they are machine‐readable, free to generate and access, and are consistent across publishers and journals. The pilot was launched in February of 2014 and over 300 articles have appeared that report RRIDs. The number of journals participating has expanded from the original 25 to more than 40, with RRIDs appearing in 62 different journals to date. Here we present an overview of the pilot project and its outcomes to date. We show that authors are able to identify resources and are supportive of the goals of the project. Identifiability of the resources post‐pilot showed a dramatic improvement for all three resource types, suggesting that the project has had a significant impact on identifiability of research resources. J. Comp. Neurol. 524:8–22, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Anita Bandrowski
- Center for Research in Biological Systems, UCSD, La Jolla, California, USA
| | - Matthew Brush
- Oregon Health & Science University (OHSU) Library, Department of Medical Informatics & Clinical Epidemiology, Portland, Oregon, USA
| | - Jeffery S Grethe
- Center for Research in Biological Systems, UCSD, La Jolla, California, USA
| | - Melissa A Haendel
- Oregon Health & Science University (OHSU) Library, Department of Medical Informatics & Clinical Epidemiology, Portland, Oregon, USA
| | - David N Kennedy
- University of Massachusetts Medical School, Department of Psychiatry, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Sean Hill
- Karolinska Institutet, Stockholm, Sweden
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Maryann E Martone
- Center for Research in Biological Systems, UCSD, La Jolla, California, USA
| | | | | | | | | | - Nicole Vasilevsky
- Oregon Health & Science University (OHSU) Library, Department of Medical Informatics & Clinical Epidemiology, Portland, Oregon, USA
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18
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Dahl G. ATP release through pannexon channels. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0191. [PMID: 26009770 DOI: 10.1098/rstb.2014.0191] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Extracellular adenosine triphosphate (ATP) serves as a signal for diverse physiological functions, including spread of calcium waves between astrocytes, control of vascular oxygen supply and control of ciliary beat in the airways. ATP can be released from cells by various mechanisms. This review focuses on channel-mediated ATP release and its main enabler, Pannexin1 (Panx1). Six subunits of Panx1 form a plasma membrane channel termed 'pannexon'. Depending on the mode of stimulation, the pannexon has large conductance (500 pS) and unselective permeability to molecules less than 1.5 kD or is a small (50 pS), chloride-selective channel. Most physiological and pathological stimuli induce the large channel conformation, whereas the small conformation so far has only been observed with exclusive voltage activation of the channel. The interaction between pannexons and ATP is intimate. The pannexon is not only the conduit for ATP, permitting ATP efflux from cells down its concentration gradient, but the pannexon is also modulated by ATP. The channel can be activated by ATP through both ionotropic P2X as well as metabotropic P2Y purinergic receptors. In the absence of a control mechanism, this positive feedback loop would lead to cell death owing to the linkage of purinergic receptors with apoptotic processes. A control mechanism preventing excessive activation of the purinergic receptors is provided by ATP binding (with low affinity) to the Panx1 protein and gating the channel shut.
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Affiliation(s)
- Gerhard Dahl
- School of Medicine, University of Miami, 1600 NW 10th Avenue, Miami, FL 33136, USA
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19
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Bandrowski A, Brush M, Grethe JS, Haendel MA, Kennedy DN, Hill S, Hof PR, Martone ME, Pols M, Tan SC, Washington N, Zudilova-Seinstra E, Vasilevsky N. The Resource Identification Initiative: a cultural shift in publishing. Brain Behav 2016; 6:e00417. [PMID: 27110440 PMCID: PMC4834942 DOI: 10.1002/brb3.417] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A central tenet in support of research reproducibility is the ability to uniquely identify research resources, that is, reagents, tools, and materials that are used to perform experiments. However, current reporting practices for research resources are insufficient to identify the exact resources that are reported or to answer basic questions such as "How did other studies use resource X?" To address this issue, the Resource Identification Initiative was launched as a pilot project to improve the reporting standards for research resources in the methods sections of papers and thereby improve identifiability and scientific reproducibility. The pilot engaged over 25 biomedical journal editors from most major publishers, as well as scientists and funding officials. Authors were asked to include Research Resource Identifiers (RRIDs) in their manuscripts prior to publication for three resource types: antibodies, model organisms, and tools (i.e., software and databases). RRIDs are assigned by an authoritative database, for example, a model organism database for each type of resource. To make it easier for authors to obtain RRIDs, resources were aggregated from the appropriate databases and their RRIDs made available in a central web portal ( http://scicrunch.org/resources). RRIDs meet three key criteria: they are machine readable, free to generate and access, and are consistent across publishers and journals. The pilot was launched in February of 2014 and over 300 papers have appeared that report RRIDs. The number of journals participating has expanded from the original 25 to more than 40 with RRIDs appearing in 62 different journals to date. Here, we present an overview of the pilot project and its outcomes to date. We show that authors are able to identify resources and are supportive of the goals of the project. Identifiability of the resources post-pilot showed a dramatic improvement for all three resource types, suggesting that the project has had a significant impact on identifiability of research resources.
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Affiliation(s)
- Anita Bandrowski
- Center for Research in Biological Systems UCSD 9500 Gillman Dr.#0446 la Jolla California 92093-0446
| | - Matthew Brush
- Department of Medical Informatics & Clinical Epidemiology OHSU Library Oregon Health and Science University 3181 SW Sam Jackson Park Road Portland, Oregon 97239 USA
| | - Jeffery S Grethe
- Center for Research in Biological Systems UCSD 9500 Gillman Dr.#0446 la Jolla California 92093-0446
| | - Melissa A Haendel
- Department of Medical Informatics & Clinical Epidemiology OHSU Library Oregon Health and Science University 3181 SW Sam Jackson Park Road Portland, Oregon 97239 USA
| | - David N Kennedy
- Department of Psychiatry University of Massachusetts Medical School 365 Plantation Street Biotech One Worcester Massachusetts 01605
| | - Sean Hill
- INCF Karolinska Institutet Nobels väg 15A 171 77 Stockholm Sweden
| | - Patrick R Hof
- Department of Neuroscience Hess CSM Building Floor 10 Room 118 1470 Madison Avenue New York City New York 10029
| | - Maryann E Martone
- Center for Research in Biological Systems UCSD 9500 Gillman Dr.#0446 la Jolla California 92093-0446
| | - Maaike Pols
- Scientific Outreach Executive Faculty of 1000 Ltd Middlesex House 34-42, Cleveland Street London W1T 4LB UK
| | - Serena C Tan
- John Wiley and Sons 11 River St Hoboken New Jersey 07030
| | - Nicole Washington
- Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley California 94720
| | | | - Nicole Vasilevsky
- Department of Medical Informatics & Clinical Epidemiology OHSU Library Oregon Health and Science University 3181 SW Sam Jackson Park Road Portland, Oregon 97239 USA
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20
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Wei R, Wang J, Xu Y, Yin B, He F, Du Y, Peng G, Luo B. Probenecid protects against cerebral ischemia/reperfusion injury by inhibiting lysosomal and inflammatory damage in rats. Neuroscience 2015; 301:168-77. [PMID: 26047730 DOI: 10.1016/j.neuroscience.2015.05.070] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 05/14/2015] [Accepted: 05/28/2015] [Indexed: 10/23/2022]
Abstract
Probenecid has been used for decades to treat gout, and recent studies have revealed it is also a specific inhibitor of the pannexin-1 channel. It has been reported that the pannexin-1 channel is involved in ischemic injury. Here, we investigated the neuroprotective effect and the possible mechanisms of action of probenecid in global cerebral ischemia/reperfusion (I/R) injury in rats. Twenty minutes of transient global cerebral I/R injury was induced using the four-vessel occlusion (4-VO) method in male Sprague-Dawley rats. Different doses of probenecid were administered intravenously, intraperitoneally, or by gavage before or after reperfusion. Probenecid via all three routes protected against CA1 neuronal death when given before reperfusion. This protective effect continued when probenecid was given at 2h after reperfusion, but not at 6h. Interestingly, the protective effect regained if probenecid was given continuously for 7days after reperfusion. The release of cathepsin B and overexpression of calpain-1 after reperfusion were inhibited, while the upregulation of Hsp70 was strengthened by probenecid pre-treatment. Furthermore, the activation and proliferation of microglia and astrocytes after I/R injury were suppressed by continuous given for 7days, but only partly by a single dose at 6h of reperfusion. Thus, our data indicate that probenecid protects against transient global cerebral I/R injury probably by inhibiting calpain-cathepsin pathway and the inflammatory reaction.
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Affiliation(s)
- R Wei
- The Brain Medical Center and the Collaborative Innovation Center for Brain Science, Department of Neurology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - J Wang
- Department of Neurology, The First Affiliated Hospital, Anhui Medical University, Hefei 230022, China
| | - Y Xu
- The Brain Medical Center and the Collaborative Innovation Center for Brain Science, Department of Neurology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - B Yin
- Department of Neurology, Renmin Hospital, Wuhan University, Wuhan 430000, China
| | - F He
- The Brain Medical Center and the Collaborative Innovation Center for Brain Science, Department of Neurology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Y Du
- The Brain Medical Center and the Collaborative Innovation Center for Brain Science, Department of Neurology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - G Peng
- The Brain Medical Center and the Collaborative Innovation Center for Brain Science, Department of Neurology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - B Luo
- The Brain Medical Center and the Collaborative Innovation Center for Brain Science, Department of Neurology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
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21
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Abstract
The ubiquitous pannexin 1 (Panx1) ion- and metabolite-permeable channel mediates the release of ATP, a potent signalling molecule. In the present study, we provide striking evidence that ATP, in turn, stimulates internalization of Panx1 to intracellular membranes. These findings hold important implications for understanding the regulation of Panx1 when extracellular ATP is elevated. In the nervous system, this includes phenomena such as synaptic plasticity, pain, precursor cell development and stroke; outside of the nervous system, this includes things like skeletal and smooth muscle activity and inflammation. Within 15 min, ATP led to significant Panx1-EGFP internalization. In a series of experiments, we determined that hydrolysable ATP is the most potent stimulator of Panx1 internalization. We identified two possible mechanisms for Panx1 internalization, including activation of ionotropic purinergic (P2X) receptors and involvement of a putative ATP-sensitive residue in the first extracellular loop of Panx1 (Trp(74)). Internalization was cholesterol-dependent, but clathrin, caveolin and dynamin independent. Detailed analysis of Panx1 at specific endosome sub-compartments confirmed that Panx1 is expressed in endosome membranes of the classical degradation pathway under basal conditions and that elevation of ATP levels diverts a sub-population to recycling endosomes. This is the first report detailing endosome localization of Panx1 under basal conditions and the potential for ATP regulation of its surface expression. Given the ubiquitous expression profile of Panx1 and the importance of ATP signalling, these findings are of critical importance for understanding the role of Panx1 in health and disease.
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22
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Bandrowski A, Brush M, Grethe JS, Haendel MA, Kennedy DN, Hill S, Hof PR, Martone ME, Pols M, Tan S, Washington N, Zudilova-Seinstra E, Vasilevsky N. The Resource Identification Initiative: A cultural shift in publishing. F1000Res 2015; 4:134. [PMID: 26594330 DOI: 10.12688/f1000research.6555.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/26/2015] [Indexed: 01/10/2023] Open
Abstract
A central tenet in support of research reproducibility is the ability to uniquely identify research resources, i.e., reagents, tools, and materials that are used to perform experiments. However, current reporting practices for research resources are insufficient to allow humans and algorithms to identify the exact resources that are reported or answer basic questions such as "What other studies used resource X?" To address this issue, the Resource Identification Initiative was launched as a pilot project to improve the reporting standards for research resources in the methods sections of papers and thereby improve identifiability and reproducibility. The pilot engaged over 25 biomedical journal editors from most major publishers, as well as scientists and funding officials. Authors were asked to include Research Resource Identifiers (RRIDs) in their manuscripts prior to publication for three resource types: antibodies, model organisms, and tools (including software and databases). RRIDs represent accession numbers assigned by an authoritative database, e.g., the model organism databases, for each type of resource. To make it easier for authors to obtain RRIDs, resources were aggregated from the appropriate databases and their RRIDs made available in a central web portal ( www.scicrunch.org/resources). RRIDs meet three key criteria: they are machine readable, free to generate and access, and are consistent across publishers and journals. The pilot was launched in February of 2014 and over 300 papers have appeared that report RRIDs. The number of journals participating has expanded from the original 25 to more than 40. Here, we present an overview of the pilot project and its outcomes to date. We show that authors are generally accurate in performing the task of identifying resources and supportive of the goals of the project. We also show that identifiability of the resources pre- and post-pilot showed a dramatic improvement for all three resource types, suggesting that the project has had a significant impact on reproducibility relating to research resources.
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Affiliation(s)
- Anita Bandrowski
- Center for Research in Biological Systems, UCSD, la Jolla, CA, 92093, USA
| | - Matthew Brush
- Department of Medical Informatics & Clinical Epidemiology, OHSU, Portland, Oregon, 97239, USA
| | - Jeffery S Grethe
- Center for Research in Biological Systems, UCSD, la Jolla, CA, 92093, USA
| | - Melissa A Haendel
- Department of Medical Informatics & Clinical Epidemiology, OHSU, Portland, Oregon, 97239, USA
| | - David N Kennedy
- Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Sean Hill
- Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Maryann E Martone
- Center for Research in Biological Systems, UCSD, la Jolla, CA, 92093, USA
| | - Maaike Pols
- Scientific Outreach, Faculty of 1000 Ltd, London, W1T 4LB, UK
| | - Serena Tan
- John Wiley and Sons, Hoboken, NJ, 07030, USA
| | - Nicole Washington
- Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | | | - Nicole Vasilevsky
- Department of Medical Informatics & Clinical Epidemiology, OHSU, Portland, Oregon, 97239, USA
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23
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Bandrowski A, Brush M, Grethe JS, Haendel MA, Kennedy DN, Hill S, Hof PR, Martone ME, Pols M, Tan S, Washington N, Zudilova-Seinstra E, Vasilevsky N. The Resource Identification Initiative: A cultural shift in publishing. F1000Res 2015; 4:134. [PMID: 26594330 PMCID: PMC4648211 DOI: 10.12688/f1000research.6555.2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/25/2015] [Indexed: 11/20/2022] Open
Abstract
A central tenet in support of research reproducibility is the ability to uniquely identify research resources, i.e., reagents, tools, and materials that are used to perform experiments. However, current reporting practices for research resources are insufficient to allow humans and algorithms to identify the exact resources that are reported or answer basic questions such as “What other studies used resource X?” To address this issue, the Resource Identification Initiative was launched as a pilot project to improve the reporting standards for research resources in the methods sections of papers and thereby improve identifiability and reproducibility. The pilot engaged over 25 biomedical journal editors from most major publishers, as well as scientists and funding officials. Authors were asked to include Research Resource Identifiers (RRIDs) in their manuscripts prior to publication for three resource types: antibodies, model organisms, and tools (including software and databases). RRIDs represent accession numbers assigned by an authoritative database, e.g., the model organism databases, for each type of resource. To make it easier for authors to obtain RRIDs, resources were aggregated from the appropriate databases and their RRIDs made available in a central web portal (
www.scicrunch.org/resources). RRIDs meet three key criteria: they are machine readable, free to generate and access, and are consistent across publishers and journals. The pilot was launched in February of 2014 and over 300 papers have appeared that report RRIDs. The number of journals participating has expanded from the original 25 to more than 40. Here, we present an overview of the pilot project and its outcomes to date. We show that authors are generally accurate in performing the task of identifying resources and supportive of the goals of the project. We also show that identifiability of the resources pre- and post-pilot showed a dramatic improvement for all three resource types, suggesting that the project has had a significant impact on reproducibility relating to research resources.
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Affiliation(s)
- Anita Bandrowski
- Center for Research in Biological Systems, UCSD, la Jolla, CA, 92093, USA
| | - Matthew Brush
- Department of Medical Informatics & Clinical Epidemiology, OHSU, Portland, Oregon, 97239, USA
| | - Jeffery S Grethe
- Center for Research in Biological Systems, UCSD, la Jolla, CA, 92093, USA
| | - Melissa A Haendel
- Department of Medical Informatics & Clinical Epidemiology, OHSU, Portland, Oregon, 97239, USA
| | - David N Kennedy
- Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Sean Hill
- Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Maryann E Martone
- Center for Research in Biological Systems, UCSD, la Jolla, CA, 92093, USA
| | - Maaike Pols
- Scientific Outreach, Faculty of 1000 Ltd, London, W1T 4LB, UK
| | - Serena Tan
- John Wiley and Sons, Hoboken, NJ, 07030, USA
| | - Nicole Washington
- Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | | | - Nicole Vasilevsky
- Department of Medical Informatics & Clinical Epidemiology, OHSU, Portland, Oregon, 97239, USA
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24
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Boassa D, Nguyen P, Hu J, Ellisman MH, Sosinsky GE. Pannexin2 oligomers localize in the membranes of endosomal vesicles in mammalian cells while Pannexin1 channels traffic to the plasma membrane. Front Cell Neurosci 2015; 8:468. [PMID: 25698922 PMCID: PMC4313697 DOI: 10.3389/fncel.2014.00468] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 12/27/2014] [Indexed: 12/13/2022] Open
Abstract
Pannexin2 (Panx2) is the largest of three members of the pannexin proteins. Pannexins are topologically related to connexins and innexins, but serve different functional roles than forming gap junctions. We previously showed that pannexins form oligomeric channels but unlike connexins and innexins, they form only single membrane channels. High levels of Panx2 mRNA and protein in the Central Nervous System (CNS) have been documented. Whereas Pannexin1 (Panx1) is fairly ubiquitous and Pannexin3 (Panx3) is found in skin and connective tissue, both are fully glycosylated, traffic to the plasma membrane and have functions correlated with extracellular ATP release. Here, we describe trafficking and subcellular localizations of exogenous Panx2 and Panx1 protein expression in MDCK, HeLa, and HEK 293T cells as well as endogenous Panx1 and Panx2 patterns in the CNS. Panx2 was found in intracellular localizations, was partially N-glycosylated, and localizations were non-overlapping with Panx1. Confocal images of hippocampal sections immunolabeled for the astrocytic protein GFAP, Panx1 and Panx2 demonstrated that the two isoforms, Panx1 and Panx2, localized at different subcellular compartments in both astrocytes and neurons. Using recombinant fusions of Panx2 with appended genetic tags developed for correlated light and electron microscopy and then expressed in different cell lines, we determined that Panx2 is localized in the membrane of intracellular vesicles and not in the endoplasmic reticulum as initially indicated by calnexin colocalization experiments. Dual immunofluorescence imaging with protein markers for specific vesicle compartments showed that Panx2 vesicles are early endosomal in origin. In electron tomographic volumes, cross-sections of these vesicles displayed fine structural details and close proximity to actin filaments. Thus, pannexins expressed at different subcellular compartments likely exert distinct functional roles, particularly in the nervous system.
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Affiliation(s)
- Daniela Boassa
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA
| | - Phuong Nguyen
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA
| | - Junru Hu
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA ; Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Gina E Sosinsky
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA ; Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
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25
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Ardiles AO, Flores-Muñoz C, Toro-Ayala G, Cárdenas AM, Palacios AG, Muñoz P, Fuenzalida M, Sáez JC, Martínez AD. Pannexin 1 regulates bidirectional hippocampal synaptic plasticity in adult mice. Front Cell Neurosci 2014; 8:326. [PMID: 25360084 PMCID: PMC4197765 DOI: 10.3389/fncel.2014.00326] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/26/2014] [Indexed: 11/13/2022] Open
Abstract
The threshold for bidirectional modification of synaptic plasticity is known to be controlled by several factors, including the balance between protein phosphorylation and dephosphorylation, postsynaptic free Ca(2+) concentration and NMDA receptor (NMDAR) composition of GluN2 subunits. Pannexin 1 (Panx1), a member of the integral membrane protein family, has been shown to form non-selective channels and to regulate the induction of synaptic plasticity as well as hippocampal-dependent learning. Although Panx1 channels have been suggested to play a role in excitatory long-term potentiation (LTP), it remains unknown whether these channels also modulate long-term depression (LTD) or the balance between both types of synaptic plasticity. To study how Panx1 contributes to excitatory synaptic efficacy, we examined the age-dependent effects of eliminating or blocking Panx1 channels on excitatory synaptic plasticity within the CA1 region of the mouse hippocampus. By using different protocols to induce bidirectional synaptic plasticity, Panx1 channel blockade or lack of Panx1 were found to enhance LTP, whereas both conditions precluded the induction of LTD in adults, but not in young animals. These findings suggest that Panx1 channels restrain the sliding threshold for the induction of synaptic plasticity and underlying brain mechanisms of learning and memory.
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Affiliation(s)
- Alvaro O Ardiles
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso Valparaíso, Chile
| | - Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso Valparaíso, Chile
| | - Gabriela Toro-Ayala
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso Valparaíso, Chile
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso Valparaíso, Chile
| | - Adrian G Palacios
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso Valparaíso, Chile
| | - Pablo Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso Valparaíso, Chile ; Escuela de Medicina, Facultad de Medicina, Universidad de Valparaíso Valparaíso, Chile
| | - Marco Fuenzalida
- Centro de Neurobiología y Plasticidad Cerebral, Instituto de Fisiología, Universidad de Valparaíso Valparaíso, Chile
| | - Juan C Sáez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso Valparaíso, Chile ; Departamento de Fisiología, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso Valparaíso, Chile
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Schalper KA, Carvajal-Hausdorf D, Oyarzo MP. Possible role of hemichannels in cancer. Front Physiol 2014; 5:237. [PMID: 25018732 PMCID: PMC4073485 DOI: 10.3389/fphys.2014.00237] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 06/09/2014] [Indexed: 12/12/2022] Open
Abstract
In humans, connexins (Cxs) and pannexins (Panxs) are the building blocks of hemichannels. These proteins are frequently altered in neoplastic cells and have traditionally been considered as tumor suppressors. Alteration of Cxs and Panxs in cancer cells can be due to genetic, epigenetic and post-transcriptional/post-translational events. Activated hemichannels mediate the diffusional membrane transport of ions and small signaling molecules. In the last decade hemichannels have been shown to participate in diverse cell processes including the modulation of cell proliferation and survival. However, their possible role in tumor growth and expansion remains largely unexplored. Herein, we hypothesize about the possible role of hemichannels in carcinogenesis and tumor progression. To support this theory, we summarize the evidence regarding the involvement of hemichannels in cell proliferation and migration, as well as their possible role in the anti-tumor immune responses. In addition, we discuss the evidence linking hemichannels with cancer in diverse models and comment on the current technical limitations for their study.
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Affiliation(s)
- Kurt A Schalper
- Servicio Anatomía Patológica, Clínica Alemana de Santiago, Facultad de Medicina Clinica Alemana Universidad del Desarrollo Santiago, Chile ; Department of Pathology, Yale School of Medicine New Haven, CT, USA
| | | | - Mauricio P Oyarzo
- Servicio Anatomía Patológica, Clínica Alemana de Santiago, Facultad de Medicina Clinica Alemana Universidad del Desarrollo Santiago, Chile
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Retamal MA, Alcayaga J, Verdugo CA, Bultynck G, Leybaert L, Sáez PJ, Fernández R, León LE, Sáez JC. Opening of pannexin- and connexin-based channels increases the excitability of nodose ganglion sensory neurons. Front Cell Neurosci 2014; 8:158. [PMID: 24999316 PMCID: PMC4064533 DOI: 10.3389/fncel.2014.00158] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 05/19/2014] [Indexed: 11/23/2022] Open
Abstract
Satellite glial cells (SGCs) are the main glia in sensory ganglia. They surround neuronal bodies and form a cap that prevents the formation of chemical or electrical synapses between neighboring neurons. SGCs have been suggested to establish bidirectional paracrine communication with sensory neurons. However, the molecular mechanism involved in this cellular communication is unknown. In the central nervous system (CNS), astrocytes present connexin43 (Cx43) hemichannels and pannexin1 (Panx1) channels, and the opening of these channels allows the release of signal molecules, such as ATP and glutamate. We propose that these channels could play a role in glia-neuron communication in sensory ganglia. Therefore, we studied the expression and function of Cx43 and Panx1 in rat and mouse nodose-petrosal-jugular complexes (NPJcs) using confocal immunofluorescence, molecular and electrophysiological techniques. Cx43 and Panx1 were detected in SGCs and in sensory neurons, respectively. In the rat and mouse, the electrical activity of vagal nerve increased significantly after nodose neurons were exposed to a Ca2+/Mg2+-free solution, a condition that increases the open probability of Cx hemichannels. This response was partially mimicked by a cell-permeable peptide corresponding to the last 10 amino acids of Cx43 (TAT-Cx43CT). Enhanced neuronal activity was reduced by Cx hemichannel, Panx1 channel and P2X7 receptor blockers. Moreover, the role of Panx1 was confirmed in NPJc, because in those from Panx1 knockout mice showed a reduced increase of neuronal activity induced by Ca2+/Mg2+-free extracellular conditions. The data suggest that Cx hemichannels and Panx channels serve as paracrine communication pathways between SGCs and neurons by modulating the excitability of sensory neurons.
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Affiliation(s)
- Mauricio A Retamal
- Facultad de Medicina, Centro de Fisiología Celular e Integrativa, Clínica Alemana Universidad del Desarrollo Santiago, Chile ; Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Julio Alcayaga
- Laboratorio de Fisiología Celular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile Santiago, Chile
| | - Christian A Verdugo
- Facultad de Medicina, Centro de Fisiología Celular e Integrativa, Clínica Alemana Universidad del Desarrollo Santiago, Chile
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine Leuven, Belgium
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University Ghent, Belgium
| | - Pablo J Sáez
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Ricardo Fernández
- Facultad de Ciencias Biológicas y Facultad de Medicina, Universidad Andrés Bello Santiago, Chile
| | - Luis E León
- Facultad de Medicina, Centro de Genética Humana, Clínica Alemana Universidad del Desarrollo Santiago, Chile
| | - Juan C Sáez
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile ; Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto Milenio Valparaíso, Chile
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Gaynullina D, Tarasova OS, Kiryukhina OO, Shestopalov VI, Panchin Y. Endothelial function is impaired in conduit arteries of pannexin1 knockout mice. Biol Direct 2014; 9:8. [PMID: 24885326 PMCID: PMC4046076 DOI: 10.1186/1745-6150-9-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 05/14/2014] [Indexed: 11/21/2022] Open
Abstract
Pannexin1 is ubiquitously expressed in vertebrate tissues, but the role it plays in vascular tone regulation remains unclear. We found that Pannexin1 expression level is much higher in the endothelium relative to smooth muscle of saphenous artery. The ability of endothelium-intact arteries for dilation was significantly impaired whereas contractile responses were considerably increased in mice with genetic ablation of Pannexin1. No such increased contractile responses were detected in the endothelium-denuded arteries. Combined, our findings suggest a new function of Pannexin1 as an important player in normal endothelium-dependent regulation of arterial tone, where it facilitates vessel dilation and attenuates constriction. Reviewed by Dr. Armen Mulkidjanian and Dr. Alexander Lobkovsky.
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Affiliation(s)
- Dina Gaynullina
- Department of Human and Animal Physiology, Faculty of Biology, M,V, Lomonosov Moscow State University, Leninskie Gory 1-12, 119234 Moscow, Russia.
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Abstract
The pannexins (Panxs) are a family of chordate proteins homologous to the invertebrate gap junction forming proteins named innexins. Three distinct Panx paralogs (Panx1, Panx2, and Panx3) are shared among the major vertebrate phyla, but they appear to have suppressed (or even lost) their ability to directly couple adjacent cells. Connecting the intracellular and extracellular compartments is now widely accepted as Panx's primary function, facilitating the passive movement of ions and small molecules along electrochemical gradients. The tissue distribution of the Panxs ranges from pervasive to very restricted, depending on the paralog, and are often cell type-specific and/or developmentally regulated within any given tissue. In recent years, Panxs have been implicated in an assortment of physiological and pathophysiological processes, particularly with respect to ATP signaling and inflammation, and they are now considered to be a major player in extracellular purinergic communication. The following is a comprehensive review of the Panx literature, exploring the historical events leading up to their discovery, outlining our current understanding of their biochemistry, and describing the importance of these proteins in health and disease.
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Affiliation(s)
- Stephen R Bond
- Genome Technology Branch, Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health Bethesda, MD, USA ; Department of Cellular and Physiological Science, Life Sciences Institute, University of British Columbia Vancouver, BC, Canada
| | - Christian C Naus
- Department of Cellular and Physiological Science, Life Sciences Institute, University of British Columbia Vancouver, BC, Canada
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30
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Salameh A, Blanke K, Dhein S. Mind the gap! Connexins and pannexins in physiology, pharmacology and disease. Front Pharmacol 2013; 4:144. [PMID: 24312055 PMCID: PMC3836048 DOI: 10.3389/fphar.2013.00144] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 11/04/2013] [Indexed: 11/13/2022] Open
Affiliation(s)
- Aida Salameh
- Department of Paediatric Cardiology, Heart Centre University of Leipzig Leipzig, Germany
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Lutz SE, González-Fernández E, Ventura JCC, Pérez-Samartín A, Tarassishin L, Negoro H, Patel NK, Suadicani SO, Lee SC, Matute C, Scemes E. Contribution of pannexin1 to experimental autoimmune encephalomyelitis. PLoS One 2013; 8:e66657. [PMID: 23885286 PMCID: PMC3688586 DOI: 10.1371/journal.pone.0066657] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 05/08/2013] [Indexed: 11/19/2022] Open
Abstract
Pannexin1 (Panx1) is a plasma membrane channel permeable to relatively large molecules, such as ATP. In the central nervous system (CNS) Panx1 is found in neurons and glia and in the immune system in macrophages and T-cells. We tested the hypothesis that Panx1-mediated ATP release contributes to expression of Experimental Autoimmune Encephalomyelitis (EAE), an animal model for multiple sclerosis, using wild-type (WT) and Panx1 knockout (KO) mice. Panx1 KO mice displayed a delayed onset of clinical signs of EAE and decreased mortality compared to WT mice, but developed as severe symptoms as the surviving WT mice. Spinal cord inflammatory lesions were also reduced in Panx1 KO EAE mice during acute disease. Additionally, pharmacologic inhibition of Panx1 channels with mefloquine (MFQ) reduced severity of acute and chronic EAE when administered before or after onset of clinical signs. ATP release and YoPro uptake were significantly increased in WT mice with EAE as compared to WT non-EAE and reduced in tissues of EAE Panx1 KO mice. Interestingly, we found that the P2X7 receptor was upregulated in the chronic phase of EAE in both WT and Panx1 KO spinal cords. Such increase in receptor expression is likely to counterbalance the decrease in ATP release recorded from Panx1 KO mice and thus contribute to the development of EAE symptoms in these mice. The present study shows that a Panx1 dependent mechanism (ATP release and/or inflammasome activation) contributes to disease progression, and that inhibition of Panx1 using pharmacology or gene disruption delays and attenuates clinical signs of EAE.
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Affiliation(s)
- Sarah E. Lutz
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | | | | | | | - Leonid Tarassishin
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York United States of America
| | - Hiromitsu Negoro
- Department of Urology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Naman K. Patel
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Sylvia O. Suadicani
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
- Department of Urology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Sunhee C. Lee
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York United States of America
| | - Carlos Matute
- Departamento de Neurociencias, Universidad del País Vasco, Leioa, Spain
| | - Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail:
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Hanstein R, Negoro H, Patel NK, Charollais A, Meda P, Spray DC, Suadicani SO, Scemes E. Promises and pitfalls of a Pannexin1 transgenic mouse line. Front Pharmacol 2013; 4:61. [PMID: 23675350 PMCID: PMC3648696 DOI: 10.3389/fphar.2013.00061] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 04/20/2013] [Indexed: 12/26/2022] Open
Abstract
Gene targeting strategies have become a powerful technology for elucidating mammalian gene function. The recently generated knockout (KO)-first strategy produces a KO at the RNA processing level and also allows for the generation of conditional KO alleles by combining FLP/FRT and Cre/loxP systems, thereby providing high flexibility in gene manipulation. However, this multipurpose KO-first cassette might produce hypomorphic rather than complete KOs if the RNA processing module is bypassed. Moreover, the generation of a conditional phenotype is also dependent on specific activity of Cre recombinase. Here, we report the use of an efficient molecular biological approach to test pannexin1 (Panx1) mRNA expression in global and conditional Panx1 KO mice derived from the KO-first mouse line, Panx1tm1a(KOMP)Wtsi. Using qRT-PCR, we demonstrate that tissues from wild-type (WT) mice show a range of Panx1 mRNA expression levels, with highest expression in trigeminal ganglia, bladder and spleen. Unexpectedly, we found that in mice homozygous for the KO-first allele, Panx1 mRNA expression is not abolished but reduced by 70% compared to that of WT tissues. Thus, Panx1 KO-first mice present a hypomorphic phenotype. Crosses of Panx1 KO-first with FLP deleter mice generated Panx1f/f mice. Further crosses of the latter mice with mGFAP-Cre or NFH-Cre mice were used to generate astrocyte- and neuron-specific Panx1 deletions, respectively. A high incidence of ectopic Cre expression was found in offspring of both types of conditional Panx1 KO mice. Our study demonstrates that Panx1 expression levels in the global and conditional Panx1 KO mice derived from KO-first mouse lines must be carefully characterized to ensure modulation of Panx1 gene expression. The precise quantitation of Panx1 expression and its relation to function is expected to provide a foundation for future efforts aimed at deciphering the role of Panx1 under physiological and pathological conditions.
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Affiliation(s)
- Regina Hanstein
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Yeshiva University New York, NY, USA
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