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Cibelli A, Mola MG, Saracino E, Barile B, Abbrescia P, Mogni G, Spray DC, Scemes E, Rossi A, Spennato D, Svelto M, Frigeri A, Benfenati V, Nicchia GP. Aquaporin-4 and transient receptor potential vanilloid 4 balance in early postnatal neurodevelopment. Glia 2024; 72:938-959. [PMID: 38362923 DOI: 10.1002/glia.24512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 02/17/2024]
Abstract
In the adult brain, the water channel aquaporin-4 (AQP4) is expressed in astrocyte endfoot, in supramolecular assemblies, called "Orthogonal Arrays of Particles" (OAPs) together with the transient receptor potential vanilloid 4 (TRPV4), finely regulating the cell volume. The present study aimed at investigating the contribution of AQP4 and TRPV4 to CNS early postnatal development using WT and AQP4 KO brain and retina and neuronal stem cells (NSCs), as an in vitro model of astrocyte differentiation. Western blot analysis showed that, differently from AQP4 and the glial cell markers, TRPV4 was downregulated during CNS development and NSC differentiation. Blue native/SDS-PAGE revealed that AQP4 progressively organized into OAPs throughout the entire differentiation process. Fluorescence quenching assay indicated that the speed of cell volume changes was time-related to NSC differentiation and functional to their migratory ability. Calcium imaging showed that the amplitude of TRPV4 Ca2+ transient is lower, and the dynamics are changed during differentiation and suppressed in AQP4 KO NSCs. Overall, these findings suggest that early postnatal neurodevelopment is subjected to temporally modulated water and Ca2+ dynamics likely to be those sustaining the biochemical and physiological mechanisms responsible for astrocyte differentiation during brain and retinal development.
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Affiliation(s)
- Antonio Cibelli
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Bari, Italy
| | - Maria Grazia Mola
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Bari, Italy
| | - Emanuela Saracino
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Bologna, Italy
| | - Barbara Barile
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Bari, Italy
| | - Pasqua Abbrescia
- Department of Translational Biomedicine and Neuroscience, University of Bari Aldo Moro-Medical School, Bari, Italy
| | - Guido Mogni
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Bari, Italy
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Eliana Scemes
- Department of Cell Biology and Anatomy, NY Medical College, Valhalla, New York, USA
| | - Andrea Rossi
- Genome Engineering and Model Development Lab (GEMD), IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Diletta Spennato
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Bologna, Italy
| | - Maria Svelto
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Bari, Italy
| | - Antonio Frigeri
- Department of Translational Biomedicine and Neuroscience, University of Bari Aldo Moro-Medical School, Bari, Italy
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Valentina Benfenati
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Bologna, Italy
| | - Grazia Paola Nicchia
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Bari, Italy
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Bologna, Italy
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
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2
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Cibelli A, Dohare P, Spray DC, Scemes E. Differential activation of mouse and human Panx1 channel variants. PLoS One 2023; 18:e0295710. [PMID: 38100403 PMCID: PMC10723736 DOI: 10.1371/journal.pone.0295710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023] Open
Abstract
Pannexins are ubiquitously expressed in human and mouse tissues. Pannexin 1 (Panx1), the most thoroughly characterized member of this family, forms plasmalemmal membrane channels permeable to relatively large molecules, such as ATP. Although human and mouse Panx1 amino acid sequences are conserved in the presently known regulatory sites involved in trafficking and modulation of the channel, differences are reported in the N- and C-termini of the protein, and the mechanisms of channel activation by different stimuli remain controversial. Here we used a neuroblastoma cell line to study the activation properties of endogenous mPanx1 and exogenously expressed hPanx1. Dye uptake and electrophysiological recordings revealed that in contrast to mouse Panx1, the human ortholog is insensitive to stimulation with high extracellular [K+] but responds similarly to activation of the purinergic P2X7 receptor. The two most frequent Panx1 polymorphisms found in the human population, Q5H (rs1138800) and E390D (rs74549886), exogenously expressed in Panx1-null N2a cells revealed that regarding P2X7 receptor mediated Panx1 activation, the Q5H mutant is a gain of function whereas the E390D mutant is a loss of function variant. Collectively, we demonstrate differences in the activation between human and mouse Panx1 orthologs and suggest that these differences may have translational implications for studies where Panx1 has been shown to have significant impact.
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Affiliation(s)
- Antonio Cibelli
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Preeti Dohare
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - David C. Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Eliana Scemes
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States of America
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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. bioRxiv 2023:2023.01.16.524236. [PMID: 36711845 PMCID: PMC9882221 DOI: 10.1101/2023.01.16.524236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Pannexin 1 (Panx1) are ubiquitously expressed proteins that form plasma membrane channels permeable to anions and moderate sized signaling molecules (e.g., ATP, glutamate). In the nervous system, activation of Panx1 channels have been extensively shown to contribute to distinct neurological disorders (epilepsy, chronic pain, migraine, neuroAIDS, etc.) but knowledge of 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 8-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 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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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Cibelli A, Stout R, Timmermann A, de Menezes L, Guo P, Maass K, Seifert G, Steinhäuser C, Spray DC, Scemes E. Cx43 carboxyl terminal domain determines AQP4 and Cx30 endfoot organization and blood brain barrier permeability. Sci Rep 2021; 11:24334. [PMID: 34934080 PMCID: PMC8692511 DOI: 10.1038/s41598-021-03694-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 12/06/2021] [Indexed: 11/08/2022] Open
Abstract
The neurovascular unit (NVU) consists of cells intrinsic to the vessel wall, the endothelial cells and pericytes, and astrocyte endfeet that surround the vessel but are separated from it by basement membrane. Endothelial cells are primarily responsible for creating and maintaining blood-brain-barrier (BBB) tightness, but astrocytes contribute to the barrier through paracrine signaling to the endothelial cells and by forming the glia limitans. Gap junctions (GJs) between astrocyte endfeet are composed of connexin 43 (Cx43) and Cx30, which form plaques between cells. GJ plaques formed of Cx43 do not diffuse laterally in the plasma membrane and thus potentially provide stable organizational features to the endfoot domain, whereas GJ plaques formed of other connexins and of Cx43 lacking a large portion of its cytoplasmic carboxyl terminus are quite mobile. In order to examine the organizational features that immobile GJs impose on the endfoot, we have used super-resolution confocal microscopy to map number and sizes of GJ plaques and aquaporin (AQP)-4 channel clusters in the perivascular endfeet of mice in which astrocyte GJs (Cx30, Cx43) were deleted or the carboxyl terminus of Cx43 was truncated. To determine if BBB integrity was compromised in these transgenic mice, we conducted perfusion studies under elevated hydrostatic pressure using horseradish peroxide as a molecular probe enabling detection of micro-hemorrhages in brain sections. These studies revealed that microhemorrhages were more numerous in mice lacking Cx43 or its carboxyl terminus. In perivascular domains of cerebral vessels, we found that density of Cx43 GJs was higher in the truncation mutant, while GJ size was smaller. Density of perivascular particles formed by AQP4 and its extended isoform AQP4ex was inversely related to the presence of full length Cx43, whereas the ratio of sizes of the particles of the AQP4ex isoform to total AQP4 was directly related to the presence of full length Cx43. Confocal analysis showed that Cx43 and Cx30 were substantially colocalized in astrocyte domains near vasculature of truncation mutant mice. These results showing altered distribution of some astrocyte nexus components (AQP4 and Cx30) in Cx43 null mice and in a truncation mutant, together with leakier cerebral vasculature, support the hypothesis that localization and mobility of gap junction proteins and their binding partners influences organization of astrocyte endfeet which in turn impacts BBB integrity of the NVU.
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Affiliation(s)
- Antonio Cibelli
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Randy Stout
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, USA
| | - Aline Timmermann
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Laura de Menezes
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
- Insitute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Peng Guo
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
- Cellular Imaging Core Facility, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Karen Maass
- Cardiovascular Research Center, NYU Grossman School of Medicine, New York, NY, USA
| | - Gerald Seifert
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Eliana Scemes
- Department of Anatomy and Cell Biology, New York Medical College, Valhalla, NY, 10595, USA.
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Luu R, Valdebenito S, Scemes E, Cibelli A, Spray DC, Rovegno M, Tichauer J, Cottignies-Calamarte A, Rosenberg A, Capron C, Belouzard S, Dubuisson J, Annane D, de la Grandmaison GL, Cramer-Bordé E, Bomsel M, Eugenin E. Pannexin-1 channel opening is critical for COVID-19 pathogenesis. iScience 2021; 24:103478. [PMID: 34841222 PMCID: PMC8603863 DOI: 10.1016/j.isci.2021.103478] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/30/2021] [Accepted: 11/16/2021] [Indexed: 12/24/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly rampaged worldwide, causing a pandemic of coronavirus disease (COVID -19), but the biology of SARS-CoV-2 remains under investigation. We demonstrate that both SARS-CoV-2 spike protein and human coronavirus 229E (hCoV-229E) or its purified S protein, one of the main viruses responsible for the common cold, induce the transient opening of Pannexin-1 (Panx-1) channels in human lung epithelial cells. However, the Panx-1 channel opening induced by SARS-CoV-2 is greater and more prolonged than hCoV-229E/S protein, resulting in an enhanced ATP, PGE2, and IL-1β release. Analysis of lung lavages and tissues indicate that Panx-1 mRNA expression is associated with increased ATP, PGE2, and IL-1β levels. Panx-1 channel opening induced by SARS-CoV-2 spike protein is angiotensin-converting enzyme 2 (ACE-2), endocytosis, and furin dependent. Overall, we demonstrated that Panx-1 channel is a critical contributor to SARS-CoV-2 infection and should be considered as an alternative therapy.
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Affiliation(s)
- Ross Luu
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX 77555, USA
| | - Silvana Valdebenito
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX 77555, USA
| | - Eliana Scemes
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY, USA
| | - Antonio Cibelli
- Dominick P. Purpura Department of Neuroscience & Department of Medicine (Cardiology), Albert Einstein College of Medicine, New York, NY 10461, USA
| | - David C Spray
- Dominick P. Purpura Department of Neuroscience & Department of Medicine (Cardiology), Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Maximiliano Rovegno
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Tichauer
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Andrea Cottignies-Calamarte
- Hôpital Cochin, Service de Virologie, Hôpital Cochin (AP-HP), Paris, France.,Service d'Hématologie Hôpital Ambroise Paré (AP-HP), Boulogne-Billancourt, France
| | - Arielle Rosenberg
- Hôpital Cochin, Service de Virologie, Hôpital Cochin (AP-HP), Paris, France.,Service d'Hématologie Hôpital Ambroise Paré (AP-HP), Boulogne-Billancourt, France.,Virologie Moléculaire et Cellulaire des Coronavirus, Centre d'infection et d'immunité de Lille, Institut Pasteur de Lille, Université de Lille, CNRS, Inserm, CHRU, 59000 Lille, France
| | - Calude Capron
- Service des Maladies Infectieuses, Centre Hospitalier Universitaire Raymond Poincaré, AP-HP, Garches, France
| | | | - Jean Dubuisson
- Intensive Care Unit, Raymond Poincaré Hospital (AP-HP), Paris, France
| | - Djillali Annane
- Simone Veil School of Medicine, Université of Versailles, Versailles, France.,University Paris Saclay, Garches, France
| | - Geoffroy Lorin de la Grandmaison
- Department of Forensic Medicine and Pathology, Versailles Saint-Quentin Université, AP-HP, Raymond Poincaré Hospital, Garches, France
| | | | - Morgane Bomsel
- Mucosal Entry of HIV and Mucosal Immunity, Institut Cochin, Université de Paris, Paris, France.,INSERM U1016, Paris, France
| | - Eliseo Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX 77555, USA
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7
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Gorska AM, Donoso M, Valdebenito S, Prideaux B, Queen S, Scemes E, Clements J, Eugenin E. Human immunodeficiency virus-1/simian immunodeficiency virus infection induces opening of pannexin-1 channels resulting in neuronal synaptic compromise: A novel therapeutic opportunity to prevent NeuroHIV. J Neurochem 2021; 158:500-521. [PMID: 33899944 DOI: 10.1111/jnc.15374] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/27/2021] [Accepted: 04/21/2021] [Indexed: 01/16/2023]
Abstract
In healthy conditions, pannexin-1 (Panx-1) channels are in a close state, but in several pathological conditions, including human immunodeficiency virus-1 (HIV) and NeuroHIV, the channel becomes open. However, the mechanism or contribution of Panx-1 channels to the HIV pathogenesis and NeuroHIV is unknown. To determine the contribution of Panx-1 channels to the pathogenesis of NeuroHIV, we used a well-established model of simian immunodeficiency virus (SIV) infection in macaques (Macaca mulatta) in the presence of and absence of a Panx-1 blocker to later examine the synaptic/axonal compromise induced for the virus. Using Golgi's staining, we demonstrated that SIV infection compromised synaptic and axonal structures, especially in the white matter. Blocking Panx-1 channels after SIV infection prevented the synaptic and axonal compromise induced by the virus, especially by maintaining the more complex synapses. Our data demonstrated that targeting Panx-1 channels can prevent and maybe revert brain synaptic compromise induced by SIV infection.
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Affiliation(s)
- Anna Maria Gorska
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Maribel Donoso
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Silvana Valdebenito
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Brendan Prideaux
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Suzanne Queen
- Department of Molecular and Comparative Pathobiology, John Hopkins Medical Center, Baltimore, MD, USA
| | - Eliana Scemes
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Janice Clements
- Department of Molecular and Comparative Pathobiology, John Hopkins Medical Center, Baltimore, MD, USA
| | - Eliseo Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
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Abstract
Pannexin1 (Panx1) is an ATP release channel expressed in neurons and astrocytes that plays important roles in CNS physiology and pathology. Evidence for the involvement of Panx1 in seizures includes the reduction of epileptiform activity and ictal discharges following Panx1 channel blockade or deletion. However, very little is known about the relative contribution of astrocyte and neuronal Panx1 channels to hyperexcitability. To this end, mice with global and cell type specific deletion of Panx1 were used in one in vivo and two in vitro seizure models. In the low-Mg2+ in vitro model, global deletion but not cell-type specific deletion of Panx1 reduced the frequency of epileptiform discharges. This reduced frequency of discharges did not impact the overall power spectra obtained from local field potentials. In the in vitro KA model, in contrast, global or cell type specific deletion of Panx1 did not affect the frequency of discharges, but reduced the overall power spectra. EEG recordings following KA-injection in vivo revealed that although global deletion of Panx1 did not affect the onset of status epilepticus (SE), SE onset was delayed in mice lacking neuronal Panx1 and accelerated in mice lacking astrocyte Panx1. EEG power spectral analysis disclosed a Panx1-dependent cortical region effect; while in the occipital region, overall spectral power was reduced in all three Panx1 genotypes; in the frontal cortex, the overall power was not affected by deletion of Panx1. Together, our results show that the contribution of Panx1 to ictal activity is model, cell-type and brain region dependent.
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Affiliation(s)
- Price Obot
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States
| | - Libor Velíšek
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States.,Department of Neurology, New York Medical College, Valhalla, New York, United States.,Department of Pediatrics, New York Medical College, Valhalla, New York, United States
| | - Jana Velíšková
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States.,Department of Neurology, New York Medical College, Valhalla, New York, United States.,Department of Obstetrics & Gynecology, New York Medical College, Valhalla, New York, United States
| | - Eliana Scemes
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States
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Cibelli A, Veronica Lopez-Quintero S, Mccutcheon S, Scemes E, Spray DC, Stout RF, Suadicani SO, Thi MM, Urban-Maldonado M. Generation and Characterization of Immortalized Mouse Cortical Astrocytes From Wildtype and Connexin43 Knockout Mice. Front Cell Neurosci 2021; 15:647109. [PMID: 33790744 PMCID: PMC8005635 DOI: 10.3389/fncel.2021.647109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/18/2021] [Indexed: 11/17/2022] Open
Abstract
We transduced mouse cortical astrocytes cultured from four litters of embryonic wildtype (WT) and connexin43 (Cx43) null mouse pups with lentiviral vector encoding hTERT and measured expression of astrocyte-specific markers up to passage 10 (p10). The immortalized cell lines thus generated (designated IWCA and IKOCA, respectively) expressed biomarkers consistent with those of neonatal astrocytes, including Cx43 from wildtype but not from Cx43-null mice, lack of Cx30, and presence of Cx26. AQP4, the water channel that is found in high abundance in astrocyte end-feet, was expressed at moderately high levels in early passages, and its mRNA and protein declined to low but still detectable levels by p10. The mRNA levels of the astrocyte biomarkers aldehyde dehydrogenase 1L1 (ALDH1L1), glutamine synthetase (GS) and glial fibrillary acidic protein (GFAP) remained relatively constant during successive passages. GS protein expression was maintained while GFAP declined with cell passaging but was still detectable at p10. Both mRNA and protein levels of glutamate transporter 1 (GLT-1) declined with passage number. Immunostaining at corresponding times was consistent with the data from Western blots and provided evidence that these proteins were expressed at appropriate intracellular locations. Consistent with our goal of generating immortalized cell lines in which Cx43 was either functionally expressed or absent, IWCA cells were found to be well coupled with respect to intercellular dye transfer and similar to primary astrocyte cultures in terms of time course of junction formation, electrical coupling strength and voltage sensitivity. Moreover, barrier function was enhanced in co-culture of the IWCA cell line with bEnd.3 microvascular endothelial cells. In addition, immunostaining revealed oblate endogenous Cx43 gap junction plaques in IWCA that were similar in appearance to those plaques obtained following transfection of IKOCA cells with fluorescent protein tagged Cx43. Re-expression of Cx43 in IKOCA cells allows experimental manipulation of connexins and live imaging of interactions between connexins and other proteins. We conclude that properties of these cell lines resemble those of primary cultured astrocytes, and they may provide useful tools in functional studies by facilitating genetic and pharmacological manipulations in the context of an astrocyte-appropriate cellular environment.
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Affiliation(s)
- Antonio Cibelli
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, United States
| | | | - Sean Mccutcheon
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, United States
| | - Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, United States
| | - David C. Spray
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, United States,Department of Medicine (Cardiology), Albert Einstein College of Medicine, New York, NY, United States,*Correspondence: David C. Spray,
| | - Randy F. Stout
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, United States,Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, New York, NY, United States,Randy J. Stout Jr.,
| | - Sylvia O. Suadicani
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, United States,Department of Urology, Albert Einstein College of Medicine, New York, NY, United States,Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, NY, United States
| | - Mia M. Thi
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, United States,Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, NY, United States,Department of Orthopaedic Surgery, Albert Einstein College of Medicine, New York, NY, United States
| | - Marcia Urban-Maldonado
- Department of Urology, Albert Einstein College of Medicine, New York, NY, United States,Department of Orthopaedic Surgery, Albert Einstein College of Medicine, New York, NY, United States
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10
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Abstract
ATP- and adenosine-mediated signaling are prominent types of glia–glia and glia–neuron interaction, with an imbalance of ATP/adenosine ratio leading to altered states of excitability, as seen in epileptic seizures. Pannexin1 (Panx1), a member of the gap junction family, is an ATP release channel that is expressed in astrocytes and neurons. Previous studies provided evidence supporting a role for purinergic-mediated signaling via Panx1 channels in seizures; using mice with global deletion of Panx1, it was shown that these channels contribute in maintenance of seizures by releasing ATP. However, nothing is known about the extent to which astrocyte and neuronal Panx1 might differently contribute to seizures. We here show that targeted deletion of Panx1 in astrocytes or neurons has opposing effects on acute seizures induced by kainic acid. The absence of Panx1 in astrocytes potentiates while the absence of Panx1 in neurons attenuates seizure manifestation. Immunohistochemical analysis performed in brains of these mice, revealed that adenosine kinase (ADK), an enzyme that regulates extracellular levels of adenosine, was increased only in seized GFAP-Cre:Panx1f/f mice. Pretreating mice with the ADK inhibitor, idotubercidin, improved seizure outcome and prevented the increase in ADK immunoreactivity. Together, these data suggest that the worsening of seizures seen in mice lacking astrocyte Panx1 is likely related to low levels of extracellular adenosine due to the increased ADK levels in astrocytes. Our study not only reveals an unexpected link between Panx1 channels and ADK but also highlights the important role played by astrocyte Panx1 channels in controlling neuronal activity.
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Affiliation(s)
- Eliana Scemes
- 1 Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Libor Velíšek
- 1 Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA.,2 Departments of Neurology and Pediatrics, New York Medical College, Valhalla, NY, USA
| | - Jana Velíšková
- 1 Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA.,3 Departments of Obstetrics & Gynecology and Neurology, New York Medical College, Valhalla, NY, USA
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11
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Molica F, Meens MJ, Pelli G, Hautefort A, Emre Y, Imhof BA, Fontana P, Scemes E, Morel S, Kwak BR. Selective inhibition of Panx1 channels decreases hemostasis and thrombosis in vivo. Thromb Res 2019; 183:56-62. [PMID: 31669824 DOI: 10.1016/j.thromres.2019.09.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/30/2019] [Accepted: 09/16/2019] [Indexed: 01/01/2023]
Abstract
BACKGROUND Hemostasis is a tightly regulated physiological process to rapidly induce hemostatic plugs at sites of vascular injury. Inappropriate activation of this process may lead to thrombosis, i.e. pathological blood clot formation in uninjured vessels or on atherosclerotic lesions. ATP release through Pannexin1 (Panx1) membrane channels contributes to collagen-induced platelet aggregation in vitro. OBJECTIVE To investigate the effects of genetic and pharmacological inhibition of Panx1 on hemostasis and thrombosis in vivo. RESULTS Bleeding time after tail clipping was increased by 2.5-fold in Panx1-/- mice compared to wild-type controls, suggesting that Panx1 deficiency impairs primary hemostasis. Wire myography on mesenteric arteries revealed diminished vasoconstriction in response to phenylephrine or U446619 in Panx1-/- mice. Mice with platelet-specific deletion of Panx1 (Panx1PDel) displayed 2-fold longer tail bleeding times than Panx1fl/fl controls. Moreover, venous thromboembolism (VTE) after injection of collagen/epinephrine in the jugular vein was reduced in Panx1-/- and Panx1PDel mice. Panx1PDel mice also showed reduced FeCl3-induced thrombosis in mesenteric arteries. BrilliantBlue-FCF, a Panx1 channel inhibitor, decreased collagen-induced platelet aggregation in vitro, increased tail bleeding time and reduced VTE in wild-type mice. Furthermore, we developed a specific Panx1 blocking antibody targeting a Panx1 extracellular loop, which reduced ATP release from platelets in vitro. Treating wild-type mice with this antibody increased tail bleeding time and decreased VTE compared to control antibody. CONCLUSIONS Panx1 channel deletion or inhibition diminishes clot formation during hemostasis and thrombosis in vivo. Blocking Panx1 channels may be an attractive strategy for modulating platelet aggregation in thrombotic disease.
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Affiliation(s)
- Filippo Molica
- Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Merlijn J Meens
- Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Graziano Pelli
- Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Aurélie Hautefort
- Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Yalin Emre
- Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Beat A Imhof
- Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Pierre Fontana
- Division of Angiology and Haemostasis, Geneva University Hospitals and Geneva Platelet Group, University of Geneva, Geneva, Switzerland
| | - Eliana Scemes
- Dept of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Sandrine Morel
- Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Brenda R Kwak
- Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland; Dept of Medical Specializations - Cardiology, University of Geneva, Geneva, Switzerland.
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12
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Molica F, Meens MJ, Dubrot J, Ehrlich A, Roth CL, Morel S, Pelli G, Vinet L, Braunersreuther V, Ratib O, Chanson M, Hugues S, Scemes E, Kwak BR. Pannexin1 links lymphatic function to lipid metabolism and atherosclerosis. Sci Rep 2017; 7:13706. [PMID: 29057961 PMCID: PMC5651868 DOI: 10.1038/s41598-017-14130-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 10/06/2017] [Indexed: 12/29/2022] Open
Abstract
Extracellular ATP is a central signaling molecule in inflammatory responses. Pannexin1 (Panx1) channels release ATP in a controlled manner and have been implicated in various inflammatory pathologies, but their role in atherogenesis remains elusive. Using atherosclerosis-susceptible mouse models with ubiquitous deletion of Panx1 (Panx1−/−Apoe−/−) or with Cre recombinase-mediated deletion of Panx1 in endothelial cells and monocytes (Tie2-CreTgPanx1fl/flApoe−/−; Panx1delApoe−/−), we identified a novel role for Panx1 in the lymphatic vasculature. Atherosclerotic lesion development in response to high-cholesterol diet was enhanced in Panx1delApoe−/− mice, pointing to an atheroprotective role for Panx1 in endothelial and/or monocytic cells. Unexpectedly, atherogenesis was not changed in mice with ubiquitous Panx1 deletion, but Panx1−/−Apoe−/− mice displayed reduced body weight, serum cholesterol, triglycerides and free fatty acids, suggesting altered lipid metabolism in these Panx1-deficient mice. Mechanistically, Panx1−/−Apoe−/− mice showed impairment of lymphatic vessel function with decreased drainage of interstitial fluids and reduced dietary fat absorption. Thus, the detrimental effect of Panx1 deletion in endothelial and/or monocytic cells during atherogenesis is counterbalanced by an opposite effect resulting from impaired lymphatic function in ubiquitous Panx1-deficient mice. Collectively, our findings unveil a pivotal role of Panx1 in linking lymphatic function to lipid metabolism and atherosclerotic plaque development.
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Affiliation(s)
- Filippo Molica
- University of Geneva, Department of Pathology and Immunology, Geneva, CH-1211, Switzerland
| | - Merlijn J Meens
- University of Geneva, Department of Pathology and Immunology, Geneva, CH-1211, Switzerland
| | - Juan Dubrot
- University of Geneva, Department of Pathology and Immunology, Geneva, CH-1211, Switzerland
| | - Avigail Ehrlich
- University of Geneva, Department of Pathology and Immunology, Geneva, CH-1211, Switzerland
| | - Christel L Roth
- University of Geneva, Department of Pathology and Immunology, Geneva, CH-1211, Switzerland
| | - Sandrine Morel
- University of Geneva, Department of Pathology and Immunology, Geneva, CH-1211, Switzerland
| | - Graziano Pelli
- University of Geneva, Department of Pathology and Immunology, Geneva, CH-1211, Switzerland
| | - Laurent Vinet
- Geneva University Hospitals, Department of Radiology and Medical Informatics, Geneva, CH-1211, Switzerland.,University of Geneva and Lausanne, School of Pharmaceutical Sciences, Geneva, CH-1211, Switzerland
| | | | - Osman Ratib
- Geneva University Hospitals, Department of Radiology and Medical Informatics, Geneva, CH-1211, Switzerland
| | - Marc Chanson
- Geneva University Hospitals and University of Geneva, Department of Pediatrics and of Cell Physiology and Metabolism, Geneva, CH-1211, Switzerland
| | - Stephanie Hugues
- University of Geneva, Department of Pathology and Immunology, Geneva, CH-1211, Switzerland
| | - Eliana Scemes
- Albert Einstein College of Medicine, Department of Neuroscience, New York, NY, 10461, USA
| | - Brenda R Kwak
- University of Geneva, Department of Pathology and Immunology, Geneva, CH-1211, Switzerland. .,University of Geneva, Department of Medical Specializations - Cardiology, Geneva, CH-1211, Switzerland.
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13
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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: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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14
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Scemes E, Zammit AR, Katz MJ, Lipton RB, Derby CA. Associations of cognitive function and pain in older adults. Int J Geriatr Psychiatry 2017; 32:118-120. [PMID: 27925374 PMCID: PMC5268434 DOI: 10.1002/gps.4580] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 08/19/2016] [Accepted: 08/22/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Bronx, NY, USA
| | - Andrea R. Zammit
- Saul B. Korey Department of Neurology, Bronx, NY, USA,Einstein Aging Study Bronx, NY, USA
| | - Mindy J. Katz
- Saul B. Korey Department of Neurology, Bronx, NY, USA,Einstein Aging Study Bronx, NY, USA,Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Richard B. Lipton
- Saul B. Korey Department of Neurology, Bronx, NY, USA,Einstein Aging Study Bronx, NY, USA,Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Carol A. Derby
- Saul B. Korey Department of Neurology, Bronx, NY, USA,Einstein Aging Study Bronx, NY, USA,Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
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15
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Andre E, Yaniz-Galende E, Hamilton C, Dusting GJ, Hellen N, Poulet CE, Diez Cunado M, Smits AM, Lowe V, Eckardt D, Du Pre B, Sanz Ruiz R, Moerkamp AT, Tribulova N, Smani T, Liskova YV, Greco S, Guzzolino E, Franco D, Lozano-Velasco E, Knorr M, Pavoine C, Bukowska A, Van Linthout S, Miteva K, Sulzgruber P, Latet SC, Portnychenko A, Cannavo A, Kamilova U, Sagach VF, Santin Y, Octavia Y, Haller PM, Octavia Y, Rubies C, Dei Zotti F, Wong KHK, Gonzalez Miqueo A, Kruithof BPT, Kadur Nagaraju C, Shaposhnikova Y, Songia P, Lindner D, Wilson C, Benzoni P, Fabbri A, Campostrini G, Jorge E, Casini S, Mengarelli I, Nikolov A, Bublikov DS, Kheloufi M, Rubies C, Walker RE, Van Dijk RA, Posthuma JJ, Dumitriu IE, Karshovska E, Sakic A, Alexandru N, Martin-Lorenzo M, Molica F, Taylor RF, Mcarthur L, Crocini C, Matsuyama TA, Mazzoni L, Lin WK, Owen TJ, Scigliano M, Sheehan A, Bezerra Gurgel AR, Bromage DI, Kiss A, Ikeda G, Pickard JMJ, Wirth G, Casos K, Khudiakov A, Nistal JF, Ferrantini C, Park SJ, Di Maggio S, Gentile F, Dini L, Buyandelger B, Larrasa-Alonso J, Schirmer I, Chin SH, Cimiotti D, Martini H, Hohensinner PJ, Garabito M, Zeni F, Licholai S, De Bortoli M, Sivitskaya L, Viczenczova C, Rainer PP, Smith LE, Suna G, Gambardella J, Cozma A, De Gonzalo Calvo D, Scoditti E, Clark BJ, Mansfield C, Eckardt D, Gomez L, Llucia-Valldeperas A, De Pauw A, Porporato P, Bouzin C, Draoui N, Sonveaux P, Balligand JL, Mougenot N, Formicola L, Nadaud S, Dierick F, Hajjar RJ, Marazzi G, Sassoon D, Hulot JS, Zamora VR, Burton FL, Macquaide N, Smith GL, Hernandez D, Sivakumaran P, Millard R, Wong RCB, Pebay A, Shepherd RK, Lim SY, Owen T, Jabbour RJ, Kloc M, Kodagoda T, Denning C, Harding SE, Ramos S, Terracciano C, Gorelik J, Wei K, Bushway P, Ruiz-Lozano P, Mercola M, Moerkamp AT, Vegh AMD, Dronkers E, Lodder K, Van Herwaarden T, Goumans MJ, Pellet-Many C, Zachary I, Noack K, Bosio A, Feyen DAM, Demkes EJ, Dierickx PJ, Doevendans PA, Vos MA, Van Veen AAB, Van Laake LW, Fernandez Santos ME, Suarez Sancho S, Fuentes Arroyo L, Plasencia Martin V, Velasco Sevillano P, Casado Plasencia A, Climent AM, Guillem M, Atienza Fernandez F, Fernandez-Aviles F, Dingenouts CKE, Lodder K, Kruithof BPT, Van Herwaarden T, Vegh AMD, Goumans MJ, Smits AM, Knezl V, Szeiffova Bacova B, Egan Benova T, Viczenczova C, Goncalvesova E, Slezak J, Calderon-Sanchez E, Diaz I, Ordonez A, Salikova SP, Zaccagnini G, Voellenkle C, Sadeghi I, Maimone B, Castelvecchio S, Gaetano C, Menicanti L, Martelli F, Hatcher C, D'aurizio R, Groth M, Baugmart M, Mercatanti A, Russo F, Mariani L, Magliaro C, Pitto L, Lozano-Velasco E, Jodar-Garcia A, Galiano-Torres J, Lopez-Navarrete I, Aranega A, Wagensteen R, Quesada A, Aranega A, Franco D, Finger S, Karbach S, Kossmann S, Muenzel T, Wenzel P, Keck M, Mougenot N, Favier S, Fuand A, Atassi F, Barbier C, Lompre AM, Hulot JS, Nikonova Y, Pluteanu F, Kockskaemper J, Chilukoti RK, Wolke C, Lendeckel U, Gardemann A, Goette A, Miteva K, Pappritz K, Mueller I, El-Shafeey M, Ringe J, Tschoepe C, Pappritz K, El-Shafeey M, Ringe J, Tschoepe C, Van Linthout S, Koller L, Richter B, Blum S, Koprak M, Huelsmann M, Pacher R, Goliasch G, Wojta J, Niessner A, Van Herck PL, Claeys MJ, Haine SE, Lenders GD, Miljoen HP, Segers VF, Vandendriescche TR, Hoymans VY, Vrints CJ, Lapikova-Bryhinska T, Gurianova V, Portnichenko H, Vasylenko M, Zapara Y, Portnichenko V, Liccardo D, Lymperopoulos A, Santangelo M, Leosco D, Koch WJ, Ferrara N, Rengo G, Alieva T, Rasulova Z, Masharipova D, Dorofeyeva NA, Drachuk KO, Sicard P, Yucel Y, Dutaur M, Vindis C, Parini A, Mialet-Perez J, Van Deel ED, De Boer M, De Waard MC, Duncker DJ, Nagel F, Inci M, Santer D, Hallstroem S, Podesser BK, Kararigas G, De Boer M, Kietadisorn R, Swinnen M, Duimel H, Verheyen F, Chrifi I, Brandt MM, Cheng C, Janssens S, Moens AL, Duncker DJ, Batlle M, Dantas AP, Sanz M, Sitges M, Mont L, Guasch E, Lobysheva I, Beauloye C, Balligand JL, Vanhoutte PM, Tang EHC, Beaumont J, Lopez B, Ravassa S, Hermida N, Valencia F, Gomez-Doblas JJ, San Jose G, De Teresa E, Diez J, Van De Merbel AF, Kruithof-De Julio M, Goumans MJ, Claus P, Dries E, Angelo Singh A, Vermeulen K, Roderick HL, Sipido KR, Driesen RB, Ilchenko I, Bobronnikova L, Myasoedova V, Alamanni F, Tremoli E, Poggio P, Becher PM, Gotzhein F, Klingel K, Blankenberg S, Westermann D, Zi M, Cartwright E, Campostrini G, Bonzanni M, Milanesi R, Bucchi A, Baruscotti M, Difrancesco D, Barbuti A, Fantini M, Wilders R, Severi S, Benzoni P, Dell' Era P, Serzanti M, Olesen MS, Muneretto C, Bisleri G, Difrancesco D, Baruscotti M, Bucchi A, Barbuti A, Amoros-Figueras G, Raga S, Campos B, Alonso-Martin C, Rodriguez-Font E, Vinolas X, Cinca J, Guerra JM, Mengarelli I, Schumacher CA, Veldkamp MW, Verkerk AO, Remme CA, Veerman C, Guan K, Stauske M, Tan H, Barc J, Wilde A, Verkerk A, Bezzina C, Tsinlikov I, Tsinlikova I, Nicoloff G, Blazhev A, Garev A, Andrienko AV, Lychev VG, Vorobova EN, Anchugina DA, Vion AC, Hammoutene A, Poisson J, Dupont N, Souyri M, Tedgui A, Codogno P, Boulanger CM, Rautou PE, Dantas AP, Batlle M, Guasch E, Torres M, Montserrat JM, Almendros I, Mont L, Austin CA, Holt CM, Rijs K, Wezel A, Hamming JF, Kolodgie FD, Virmani R, Schaapherder AF, Lindeman JHN, Posma JJN, Van Oerle R, Spronk HMH, Ten Cate H, Dinkla S, Kaski JC, Schober A, Chaabane C, Ambartsumian N, Grigorian M, Bochaton-Piallat ML, Dragan E, Andrei E, Niculescu L, Georgescu A, Gonzalez-Calero L, Maroto AS, Martinez PJ, Heredero A, Aldamiz-Echevarria G, Vivanco F, Alvarez-Llamas G, Meens MJ, Pelli G, Foglia B, Scemes E, Kwak BR, Caldwell JL, Eisner DA, Dibb KM, Trafford AW, Chilton L, Smith GL, Nicklin SA, Coppini R, Ferrantini C, Yan P, Loew LM, Poggesi C, Cerbai E, Pavone FS, Sacconi L, Tanaka H, Ishibashi-Ueda H, Takamatsu T, Coppini R, Ferrantini C, Gentile F, Pioner JM, Santini L, Sartiani L, Bargelli V, Poggesi C, Mugelli A, Cerbai E, Maciejewska M, Bolton EL, Wang Y, O'brien F, Ruas M, Lei M, Sitsapesan R, Galione A, Terrar DA, Smith JG, Garcia D, Barriales-Villa R, Monserrat L, Harding SE, Denning C, Marston SB, Watson S, Tkach S, Faggian G, Terracciano CM, Perbellini F, Eiros Zamora J, Papadaki M, Messer A, Marston S, Gould I, Johnston A, Dunne M, Smith G, Kemi OJ, Pillai M, Davidson SM, Yellon DM, Tratsiakovich Y, Jang J, Gonon AT, Pernow J, Matoba T, Koga J, Egashira K, Burke N, Davidson SM, Yellon DM, Korpisalo P, Hakkarainen H, Laidinen S, Yla-Herttuala S, Ferrer-Curriu G, Perez M, Permanyer E, Blasco-Lucas A, Gracia JM, Castro MA, Barquinero J, Galinanes M, Kostina D, Kostareva A, Malashicheva A, Merino D, Ruiz L, Gomez J, Juarez C, Gil A, Garcia R, Hurle MA, Coppini R, Pioner JM, Gentile F, Mazzoni L, Rossi A, Tesi C, Belardinelli L, Olivotto I, Cerbai E, Mugelli A, Poggesi C, Eun-Ji EJ, Lim BK, Choi DJ, Milano G, Bertolotti M, De Marchis F, Zollo F, Sommariva E, Capogrossi MC, Pompilio G, Bianchi ME, Raucci A, Pioner JM, Coppini R, Scellini B, Tardiff J, Tesi C, Poggesi C, Ferrantini C, Mazzoni L, Sartiani L, Coppini R, Diolaiuti L, Ferrari P, Cerbai E, Mugelli A, Mansfield C, Luther P, Knoell R, Villalba M, Sanchez-Cabo F, Lopez-Olaneta MM, Ortiz-Sanchez P, Garcia-Pavia P, Lara-Pezzi E, Klauke B, Gerdes D, Schulz U, Gummert J, Milting H, Wake E, Kocsis-Fodor G, Brack KE, Ng GA, Kostareva A, Smolina N, Majchrzak M, Moehner D, Wies A, Milting H, Stehle R, Pfitzer G, Muegge A, Jaquet K, Maggiorani D, Lefevre L, Dutaur M, Mialet-Perez J, Parini A, Cussac D, Douin-Echinard V, Ebenbauer B, Kaun C, Prager M, Wojta J, Rega-Kaun G, Costa G, Onetti Y, Jimenez-Altayo F, Vila E, Dantas AP, Milano G, Bertolotti M, Scopece A, Piacentini L, Bianchi ME, Capogrossi MC, Pompilio G, Colombo G, Raucci A, Blaz M, Kapelak B, Sanak M, Bauce B, Calore C, Lorenzon A, Calore M, Poloni G, Mazzotti E, Rigato I, Daliento L, Basso C, Thiene G, Melacini P, Corrado D, Rampazzo A, Danilenko NG, Vaikhanskaya TG, Davydenko OG, Szeiffova Bacova B, Kura B, Egan Benova T, Yin CH, Kukreja R, Slezak J, Tribulova N, Lee DI, Sorge M, Glabe C, Paolocci N, Guarnieri C, Tomaselli GF, Kass DA, Van Eyk JE, Agnetti G, Cordwell SJ, White MY, Wojakowski W, Lynch M, Barallobre-Barreiro J, Yin X, Mayr U, White S, Jahingiri M, Hill J, Mayr M, Sorriento D, Ciccarelli M, Fiordelisi A, Campiglia P, Trimarco B, Iaccarino G, Sitar Taut AV, Schiau S, Orasan O, Halloumi W, Negrean V, Zdrenghea D, Pop D, Van Der Meer RW, Rijzewijk LJ, Smit JWA, Revuelta-Lopez E, Nasarre L, Escola-Gil JC, Lamb HJ, Llorente-Cortes V, Pellegrino M, Massaro M, Carluccio MA, Calabriso N, Wabitsch M, Storelli C, De Caterina R, Church SJ, Callagy S, Begley P, Kureishy N, Mcharg S, Bishop PN, Unwin RD, Cooper GJS, Mawad D, Perbellini F, Tonkin J, Bello SO, Simonotto JD, Lyon AR, Stevens MM, Terracciano CM, Harding SE, Kernbach M, Czichowski V, Bosio A, Fuentes L, Hernandez-Redondo I, Guillem MS, Fernandez ME, Sanz R, Atienza F, Climent AM, Fernandez-Aviles F, Soler-Botija C, Prat-Vidal C, Galvez-Monton C, Roura S, Perea-Gil I, Bragos R, Bayes-Genis A. Poster session 1Cell growth, differentiation and stem cells - Heart72Understanding the metabolism of cardiac progenitor cells: a first step towards controlling their proliferation and differentiation?73Expression of pw1/peg3 identifies a new cardiac adult stem cell population involved in post-myocardial infarction remodeling74Long-term stimulation of iPS-derived cardiomyocytes using optogenetic techniques to promote phenotypic changes in E-C coupling75Benefits of electrical stimulation on differentiation and maturation of cardiomyocytes from human induced pluripotent stem cells76Constitutive beta-adrenoceptor-mediated cAMP production controls spontaneous automaticity of human induced pluripotent stem cell-derived cardiomyocytes77Formation and stability of T-tubules in cardiomyocytes78Identification of miRNAs promoting human cardiomyocyte proliferation by regulating Hippo pathway79A direct comparison of foetal to adult epicardial cell activation reveals distinct differences relevant for the post-injury response80Role of neuropilins in zebrafish heart regeneration81Highly efficient immunomagnetic purification of cardiomyocytes derived from human pluripotent stem cells82Cardiac progenitor cells posses a molecular circadian clock and display large 24-hour oscillations in proliferation and stress tolerance83Influence of sirolimus and everolimus on bone marrow-derived mesenchymal stem cell biology84Endoglin is important for epicardial behaviour following cardiac injuryCell death and apoptosis - Heart87Ultrastructural alterations reflecting Ca2+ handling and cell-to-cell coupling disorders precede occurrence of severe arrhythmias in intact animal heart88Urocortin-1 promotes cardioprotection through ERK1/2 and EPAC pathways: role in apoptosis and necrosis89Expression p38 MAPK and Cas-3 in myocardium LV of rats with experimental heart failure at melatonin and enalapril introductionTranscriptional control and RNA species - Heart92Accumulation of beta-amyloid 1-40 in HF patients: the role of lncRNA BACE1-AS93Role of miR-182 in zebrafish and mouse models of Holt-Oram syndrome94Mir-27 distinctly regulates muscle-enriched transcription factors and growth factors in cardiac and skeletal muscle cells95AF risk factors impair PITX2 expression leading to Wnt-microRNA-ion channel remodelingCytokines and cellular inflammation - Heart98Post-infarct survival depends on the interplay of monocytes, neutrophils and interferon gamma in a mouse model of myocardial Infarction99Inflammatory cd11b/c cells play a protective role in compensated cardiac hypertrophy by promoting an orai3-related pro-survival signal100Anti-inflammatory effects of endothelin receptor blockade in the atrial tissue of spontaneously hypertensive rats101Mesenchymal stromal cells reduce NLRP3 inflammasome activity in Coxsackievirus B3-induced myocarditis102Mesenchymal stromal cells modulate monocytes trafficking in Coxsackievirus B3-induced myocarditis103The impact of regulatory T lymphocytes on long-term mortality in patients with chronic heart failure104Temporal dynamics of dendritic cells after ST-elevation myocardial infarction relate with improvement of myocardial functionGrowth factors and neurohormones - Heart107Preconditioning of hypertrophied heart: miR-1 and IGF-1 crosstalk108Modulation of catecholamine secretion from human adrenal chromaffin cells by manipulation of G protein-coupled receptor kinase-2 activity109Evaluation of cyclic adenosin-3,5- monophosphate and neurohormones in patients with chronic heart failureNitric oxide and reactive oxygen species - Heart112Hydrogen sulfide donor inhibits oxidative and nitrosative stress, cardiohemodynamics disturbances and restores cNOS coupling in old rats113Role and mechanisms of action of aldehydes produced by monoamine oxidase A in cardiomyocyte death and heart failure114Exercise training has contrasting effects in myocardial infarction and pressure-overload due to different endothelial nitric oxide synthase regulation115S-Nitroso Human Serum Albumin dose-dependently leads to vasodilation and alters reactive hyperaemia in coronary arteries of an isolated mouse heart model116Modulating endothelial nitric oxide synthase with folic acid attenuates doxorubicin-induced cardiomyopathy119Effects of long-term very high intensity exercise on aortic structure and function in an animal model120Electron paramagnetic resonance spectroscopy quantification of nitrosylated hemoglobin (HbNO) as an index of vascular nitric oxide bioavailability in vivo121Deletion of repressor activator protein 1 impairs acetylcholine-induced relaxation due to production of reactive oxygen speciesExtracellular matrix and fibrosis - Heart124MicroRNA-19b is associated with myocardial collagen cross-linking in patients with severe aortic stenosis. Potential usefulness as a circulating biomarker125A new ex vivo model to study cardiac fibrosis126Heterogeneity of fibrosis and fibroblast differentiation in the left ventricle after myocardial infarction127Effect of carbohydrate metabolism degree compensation to the level of galectin-3 changes in hypertensive patients with chronic heart failure and type 2 diabetes mellitus128Statin paradox in association with calcification of bicuspid aortic valve interstitial cells129Cardiac function remains impaired despite reversible cardiac fibrosis after healed experimental viral myocarditisIon channels, ion exchangers and cellular electrophysiology - Heart132Identifying a novel role for PMCA1 (Atp2b1) in heart rhythm instability133Mutations of the caveolin-3 gene as a predisposing factor for cardiac arrhythmias134The human sinoatrial node action potential: time for a computational model135iPSC-derived cardiomyocytes as a model to dissect ion current alterations of genetic atrial fibrillation136Postextrasystolic potentiation in healthy and diseased hearts: effects of the site of origin and coupling interval of the preceding extrasystole137Absence of Nav1.8-based (late) sodium current in rabbit cardiomyocytes and human iPSC-CMs138hiPSC-derived cardiomyocytes from Brugada Syndrome patients without identified mutations do not exhibit cellular electrophysiological abnormalitiesMicrocirculation141Atherogenic indices, collagen type IV turnover and the development of microvascular complications- study in diabetics with arterial hypertension142Changes in the microvasculature and blood viscosity in women with rheumatoid arthritis, hypercholesterolemia and hypertensionAtherosclerosis145Shear stress regulates endothelial autophagy: consequences on endothelial senescence and atherogenesis146Obstructive sleep apnea causes aortic remodeling in a chronic murine model147Aortic perivascular adipose tissue displays an aged phenotype in early and late atherosclerosis in ApoE-/- mice148A systematic evaluation of the cellular innate immune response during the process of human atherosclerosis149Inhibition of Coagulation factor Xa increases plaque stability and attenuates the onset and progression of atherosclerotic plaque in apolipoprotein e-deficient mice150Regulatory CD4+ T cells from patients with atherosclerosis display pro-inflammatory skewing and enhanced suppression function151Hypoxia-inducible factor (HIF)-1alpha regulates macrophage energy metabolism by mediating miRNAs152Extracellular S100A4 is a key player of smooth muscle cell phenotypic transition: implications in atherosclerosis153Microparticles of healthy origins improve atherosclerosis-associated endothelial progenitor cell dysfunction via microRNA transfer154Arterial remodeling and metabolism impairment in early atherosclerosis155Role of pannexin1 in atherosclerotic plaque formationCalcium fluxes and excitation-contraction coupling158Amphiphysin II induces tubule formation in cardiac cells159Interleukin 1 beta regulation of connexin 43 in cardiac fibroblasts and the effects of adult cardiac myocyte:fibroblast co-culture on myocyte contraction160T-tubular electrical defects contribute to blunted beta-adrenergic response in heart failure161Beat-to-beat variability of intracellular Ca2+ dynamics of Purkinje cells in the infarct border zone of the mouse heart revealed by rapid-scanning confocal microscopy162The efficacy of late sodium current blockers in hypertrophic cardiomyopathy is dependent on genotype: a study on transgenic mouse models with different mutations163Synthesis of cADPR and NAADP by intracellular CD38 in heart: role in inotropic and arrhythmogenic effects of beta-adrenoceptor signalingContractile apparatus166Towards an engineered heart tissue model of HCM using hiPSC expressing the ACTC E99K mutation167Diastolic mechanical load delays structural and functional deterioration of ultrathin adult heart slices in culture168Structural investigation of the cardiac troponin complex by molecular dynamics169Exercise training restores myocardial and oxidative skeletal muscle function from myocardial infarction heart failure ratsOxygen sensing, ischaemia and reperfusion172A novel antibody specific to full-length stromal derived factor-1 alpha reveals that remote conditioning induces its cleavage by endothelial dipeptidyl peptidase 4173Attenuation of myocardial and vascular arginase activity by vagal nerve stimulation via a mechanism involving alpha-7 nicotinic receptor during cardiac ischemia and reperfusion174Novel nanoparticle-mediated medicine for myocardial ischemia-reperfusion injury simultaneously targeting mitochondrial injury and myocardial inflammation175Acetylcholine plays a key role in myocardial ischaemic preconditioning via recruitment of intrinsic cardiac ganglia176The role of nitric oxide and VEGFR-2 signaling in post ischemic revascularization and muscle recovery in aged hypercholesterolemic mice177Efficacy of ischemic preconditioning to protect the human myocardium: the role of clinical conditions and treatmentsCardiomyopathies and fibrosis180Plakophilin-2 haploinsufficiency leads to impaired canonical Wnt signaling in ARVC patient181Improved technique for customized, easier, safer and more reliable transverse aortic arch banding and debanding in mice as a model of pressure overload hypertrophy182Late sodium current inhibitors for the treatment of inducible obstruction and diastolic dysfunction in hypertrophic cardiomyopathy: a study on human myocardium183Angiotensin II receptor antagonist fimasartan has protective role of left ventricular fibrosis and remodeling in the rat ischemic heart184Role of High-Mobility Group Box 1 (HMGB1) redox state on cardiac fibroblasts activities and heart function after myocardial infarction185Atrial remodeling in hypertrophic cardiomyopathy: insights from mouse models carrying different mutations in cTnT186Electrophysiological abnormalities in ventricular cardiomyocytes from a Maine Coon cat with hypertrophic cardiomyopathy: effects of ranolazine187ZBTB17 is a novel cardiomyopathy candidate gene and regulates autophagy in the heart188Inhibition of SRSF4 in cardiomyocytes induces left ventricular hypertrophy189Molecular characterization of a novel cardiomyopathy related desmin frame shift mutation190Autonomic characterisation of electro-mechanical remodeling in an in-vitro leporine model of heart failure191Modulation of Ca2+-regulatory function by three novel mutations in TNNI3 associated with severe infant restrictive cardiomyopathyAging194The aging impact on cardiac mesenchymal like stromal cells (S+P+)195Reversal of premature aging markers after bariatric surgery196Sex-associated differences in vascular remodeling during aging: role of renin-angiotensin system197Role of the receptor for advanced glycation end-products (RAGE) in age dependent left ventricle dysfunctionsGenetics and epigenetics200hsa-miR-21-5p as a key factor in aortic remodeling during aneurysm formation201Co-inheritance of mutations associated with arrhythmogenic and hypertrophic cardiomyopathy in two Italian families202Lamin a/c hot spot codon 190: form various amino acid substitutions to clinical effects203Treatment with aspirin and atorvastatin attenuate cardiac injury induced by rat chest irradiation: Implication of myocardial miR-1, miR-21, connexin-43 and PKCGenomics, proteomics, metabolomics, lipidomics and glycomics206Differential phosphorylation of desmin at serines 27 and 31 drives the accumulation of preamyloid oligomers in heart failure207Potential role of kinase Akt2 in the reduced recovery of type 2 diabetic hearts subjected to ischemia / reperfusion injury208A proteomics comparison of extracellular matrix remodelling in porcine coronary arteries upon stent implantationMetabolism, diabetes mellitus and obesity211Targeting grk2 as therapeutic strategy for cancer associated to diabetes212Effects of salbutamol on large arterial stiffness in patients with metabolic syndrome213Circulating microRNA-1 and microRNA-133a: potential biomarkers of myocardial steatosis in type 2 diabetes mellitus214Anti-inflammatory nutrigenomic effects of hydroxytyrosol in human adipocytes - protective mechanisms of mediterranean diets in obesity-related inflammation215Alterations in the metal content of different cardiac regions within a rat model of diabetic cardiomyopathyTissue engineering218A novel conductive patch for application in cardiac tissue engineering219Establishment of a simplified and improved workflow from neonatal heart dissociation to cardiomyocyte purification and characterization220Effects of flexible substrate on cardiomyocytes cell culture221Mechanical stretching on cardiac adipose progenitors upregulates sarcomere-related genes. Cardiovasc Res 2016. [DOI: 10.1093/cvr/cvw135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Velasquez S, Malik S, Lutz SE, Scemes E, Eugenin EA. Pannexin1 Channels Are Required for Chemokine-Mediated Migration of CD4+ T Lymphocytes: Role in Inflammation and Experimental Autoimmune Encephalomyelitis. J Immunol 2016; 196:4338-47. [PMID: 27076682 DOI: 10.4049/jimmunol.1502440] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 03/09/2016] [Indexed: 12/19/2022]
Abstract
Pannexin1 (Panx1) channels are large high conductance channels found in all vertebrates that can be activated under several physiological and pathological conditions. Our published data indicate that HIV infection results in the extended opening of Panx1 channels (5-60 min), allowing for the secretion of ATP through the channel pore with subsequent activation of purinergic receptors, which facilitates HIV entry and replication. In this article, we demonstrate that chemokines, which bind CCR5 and CXCR4, especially SDF-1α/CXCL12, result in a transient opening (peak at 5 min) of Panx1 channels found on CD4(+) T lymphocytes, which induces ATP secretion, focal adhesion kinase phosphorylation, cell polarization, and subsequent migration. Increased migration of immune cells is key for the pathogenesis of several inflammatory diseases including multiple sclerosis (MS). In this study, we show that genetic deletion of Panx1 reduces the number of the CD4(+) T lymphocytes migrating into the spinal cord of mice subjected to experimental autoimmune encephalomyelitis, an animal model of MS. Our results indicate that opening of Panx1 channels in response to chemokines is required for CD4(+) T lymphocyte migration, and we propose that targeting Panx1 channels could provide new potential therapeutic approaches to decrease the devastating effects of MS and other inflammatory diseases.
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Affiliation(s)
- Stephani Velasquez
- Public Health Research Institute, Rutgers New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ 07103; Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ 07103
| | - Shaily Malik
- Public Health Research Institute, Rutgers New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ 07103; Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ 07103
| | - Sarah E Lutz
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697; and
| | - Eliana Scemes
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Eliseo A Eugenin
- Public Health Research Institute, Rutgers New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ 07103; Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ 07103;
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Mola MG, Sparaneo A, Gargano CD, Spray DC, Svelto M, Frigeri A, Scemes E, Nicchia GP. The speed of swelling kinetics modulates cell volume regulation and calcium signaling in astrocytes: A different point of view on the role of aquaporins. Glia 2015; 64:139-54. [PMID: 26413835 DOI: 10.1002/glia.22921] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/14/2015] [Accepted: 09/01/2015] [Indexed: 01/11/2023]
Abstract
Regulatory volume decrease (RVD) is a process by which cells restore their original volume in response to swelling. In this study, we have focused on the role played by two different Aquaporins (AQPs), Aquaporin-4 (AQP4), and Aquaporin-1 (AQP1), in triggering RVD and in mediating calcium signaling in astrocytes under hypotonic stimulus. Using biophysical techniques to measure water flux through the plasma membrane of wild-type (WT) and AQP4 knockout (KO) astrocytes and of an astrocyte cell line (DI TNC1) transfected with AQP4 or AQP1, we here show that AQP-mediated fast swelling kinetics play a key role in triggering and accelerating RVD. Using calcium imaging, we show that AQP-mediated fast swelling kinetics also significantly increases the amplitude of calcium transients inhibited by Gadolinium and Ruthenium Red, two inhibitors of the transient receptor potential vanilloid 4 (TRPV4) channels, and prevented by removing extracellular calcium. Finally, inhibition of TRPV4 or removal of extracellular calcium does not affect RVD. All together our study provides evidence that (1) AQP influenced swelling kinetics is the main trigger for RVD and in mediating calcium signaling after hypotonic stimulus together with TRPV4, and (2) calcium influx from the extracellular space and/or TRPV4 are not essential for RVD to occur in astrocytes.
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Affiliation(s)
- Maria Grazia Mola
- Department of Bioscience, Biotechnology, and Biopharmaceutics, University of Bari "Aldo Moro,", Bari, Italy
| | - Angelo Sparaneo
- Laboratory of Oncology, IRCCS Casa Sollievo Della Sofferenza, San Giovanni Rotondo, Italy
| | - Concetta Domenica Gargano
- Department of Bioscience, Biotechnology, and Biopharmaceutics, University of Bari "Aldo Moro,", Bari, Italy
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Maria Svelto
- Department of Bioscience, Biotechnology, and Biopharmaceutics, University of Bari "Aldo Moro,", Bari, Italy
| | - Antonio Frigeri
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro,", Bari, Italy
| | - Eliana Scemes
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Grazia Paola Nicchia
- Department of Bioscience, Biotechnology, and Biopharmaceutics, University of Bari "Aldo Moro,", Bari, Italy.,Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
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Cisneros-Mejorado A, Gottlieb M, Cavaliere F, Magnus T, Koch-Nolte F, Scemes E, Pérez-Samartín A, Matute C. Blockade of P2X7 receptors or pannexin-1 channels similarly attenuates postischemic damage. J Cereb Blood Flow Metab 2015; 35:843-50. [PMID: 25605289 PMCID: PMC4420860 DOI: 10.1038/jcbfm.2014.262] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 12/19/2014] [Accepted: 12/22/2014] [Indexed: 11/09/2022]
Abstract
The role of P2X7 receptors and pannexin-1 channels in ischemic damage remains controversial. Here, we analyzed their contribution to postanoxic depolarization after ischemia in cultured neurons and in brain slices. We observed that pharmacological blockade of P2X7 receptors or pannexin-1 channels delayed the onset of postanoxic currents and reduced their slope, and that simultaneous inhibition did not further enhance the effects of blocking either one. These results were confirmed in acute cortical slices from P2X7 and pannexin-1 knockout mice. Oxygen-glucose deprivation in cortical organotypic cultures caused neuronal death that was reduced with P2X7 and pannexin-1 blockers as well as in organotypic cultures derived from mice lacking P2X7 and pannexin 1. Subsequently, we used transient middle cerebral artery occlusion to monitor the neuroprotective effect of those drugs in vivo. We found that P2X7 and pannexin-1 antagonists, and their ablation in knockout mice, substantially attenuated the motor symptoms and reduced the infarct volume to ~50% of that in vehicle-treated or wild-type animals. These results show that P2X7 receptors and pannexin-1 channels are major mediators of postanoxic depolarization in neurons and of brain damage after ischemia, and that they operate in the same deleterious signaling cascade leading to neuronal and tissue demise.
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Affiliation(s)
- Abraham Cisneros-Mejorado
- Achucarro Basque Center for Neuroscience, Departamento de Neurociencias and CIBERNED, Universidad del País Vasco (UPV/EHU), Leioa, Spain
| | - Miroslav Gottlieb
- 1] Achucarro Basque Center for Neuroscience, Departamento de Neurociencias and CIBERNED, Universidad del País Vasco (UPV/EHU), Leioa, Spain [2] Institute of Neurobiology, Slovak Academy of Sciences, Kosice, Slovak Republic
| | - Fabio Cavaliere
- 1] Achucarro Basque Center for Neuroscience, Departamento de Neurociencias and CIBERNED, Universidad del País Vasco (UPV/EHU), Leioa, Spain [2] Neurotek-UPV/EHU, Parque Tecnológico de Bizkaia, Zamudio, Spain
| | - Tim Magnus
- Department of Neurology, University Hospital Hamburg, Hamburg, Germany
| | | | - Eliana Scemes
- Dominick P. Purpura Department of Neurosciences, Albert Einstein College of Medicine, New York, New York, USA
| | - Alberto Pérez-Samartín
- 1] Achucarro Basque Center for Neuroscience, Departamento de Neurociencias and CIBERNED, Universidad del País Vasco (UPV/EHU), Leioa, Spain [2] Neurotek-UPV/EHU, Parque Tecnológico de Bizkaia, Zamudio, Spain
| | - Carlos Matute
- 1] Achucarro Basque Center for Neuroscience, Departamento de Neurociencias and CIBERNED, Universidad del País Vasco (UPV/EHU), Leioa, Spain [2] Neurotek-UPV/EHU, Parque Tecnológico de Bizkaia, Zamudio, Spain
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da Silva-Souza HA, de Lira MN, Patel NK, Spray DC, Persechini PM, Scemes E. Inhibitors of the 5-lipoxygenase pathway activate pannexin1 channels in macrophages via the thromboxane receptor. Am J Physiol Cell Physiol 2014; 307:C571-9. [PMID: 25080488 DOI: 10.1152/ajpcell.00087.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A multitude of environmental signaling molecules influence monocyte and macrophage innate and adaptive immune responses, including ATP and prostanoids. Interestingly, purinergic (P2) and eicosanoid receptor signaling interact such that the activation of P2 receptors leads to prostanoid production, which can then interfere with P2Y-mediated macrophage migration. Recent studies suggest that blockade of 5-lipoxygenase (5-LOX) in macrophages can activate a permeation pathway involved in the influx of dye and the release of ATP. Here, we provide evidence that pannexin1 (Panx1) is a component of this pathway and present the intracellular signaling molecules linking the thromboxane (TP) receptor to Panx1-mediated dye influx and ATP release. Using pharmacological tools and transgenic mice deficient in Panx1, we show that two 5-LOX pathway inhibitors induce ATP release and influx of dye in a Panx1-dependent manner. Electrophysiological recordings performed in wild-type and Panx1-deficient macrophages confirmed that these 5-LOX pathway inhibitors activate currents characteristic of Panx1 channels. We found that the mechanism by which Panx1 channels are activated under this condition involves activation of the TP receptor that is mediated by the cAMP/PKA pathway. This is to our knowledge the first evidence for the involvement of Panx1 in the TP receptor signaling pathway. Future studies aimed to clarify the contribution of this TP-Panx1 signaling network to macrophage immune responses are likely to be important for targeting inflammatory and autoimmune diseases.
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Affiliation(s)
- Hercules A da Silva-Souza
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia de Pesquisa Translacional em Saúde e Ambiente da Região Amazônica-INPeTAm, Rio de Janeiro, Brazil; and Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
| | - Maria Nathália de Lira
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Naman K Patel
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
| | - David C Spray
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
| | - Pedro Muanis Persechini
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia de Pesquisa Translacional em Saúde e Ambiente da Região Amazônica-INPeTAm, Rio de Janeiro, Brazil; and
| | - Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
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Jackson DG, Wang J, Keane RW, Scemes E, Dahl G. ATP and potassium ions: a deadly combination for astrocytes. Sci Rep 2014; 4:4576. [PMID: 24694658 PMCID: PMC3974143 DOI: 10.1038/srep04576] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 03/18/2014] [Indexed: 11/09/2022] Open
Abstract
The ATP release channel Pannexin1 (Panx1) is self-regulated, i.e. the permeant ATP inhibits the channel from the extracellular space. The affinity of the ATP binding site is lower than that of the purinergic P2X7 receptor allowing a transient activation of Panx1 by ATP through P2X7R. Here we show that the inhibition of Panx1 by ATP is abrogated by increased extracellular potassium ion concentration ([K(+)]o) in a dose-dependent manner. Since increased [K(+)]o is also a stimulus for Panx1 channels, it can be expected that a combination of ATP and increased [K(+)]o would be deadly for cells. Indeed, astrocytes did not survive exposure to these combined stimuli. The death mechanism, although involving P2X7R, does not appear to strictly follow a pyroptotic pathway. Instead, caspase-3 was activated, a process inhibited by Panx1 inhibitors. These data suggest that Panx1 plays an early role in the cell death signaling pathway involving ATP and K(+) ions. Additionally, Panx1 may play a second role once cells are committed to apoptosis, since Panx1 is also a substrate of caspase-3.
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Affiliation(s)
- David G Jackson
- Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, Florida 33136
| | - Junjie Wang
- Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, Florida 33136
| | - Robert W Keane
- Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, Florida 33136
| | - Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, 10461
| | - Gerhard Dahl
- Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, Florida 33136
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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22
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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23
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Negoro H, Lutz S, Scemes E, Suadicani S. 36 A PUTATIVE MECHANISM FOR PANNEXIN 1 INVOLVEMENT IN BLADDER DYSFUNCTION IN AN ANIMAL MODEL OF MULTIPLE SCLEROSIS. J Urol 2013. [DOI: 10.1016/j.juro.2013.02.1411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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24
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Cone AC, Ambrosi C, Scemes E, Martone ME, Sosinsky GE. A comparative antibody analysis of pannexin1 expression in four rat brain regions reveals varying subcellular localizations. Front Pharmacol 2013; 4:6. [PMID: 23390418 PMCID: PMC3565217 DOI: 10.3389/fphar.2013.00006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 01/09/2013] [Indexed: 11/13/2022] Open
Abstract
Pannexin1 (Panx1) channels release cytosolic ATP in response to signaling pathways. Panx1 is highly expressed in the central nervous system. We used four antibodies with different Panx1 anti-peptide epitopes to analyze four regions of rat brain. These antibodies labeled the same bands in Western blots and had highly similar patterns of immunofluorescence in tissue culture cells expressing Panx1, but Western blots of brain lysates from Panx1 knockout and control mice showed different banding patterns. Localizations of Panx1 in brain slices were generated using automated wide field mosaic confocal microscopy for imaging large regions of interest while retaining maximum resolution for examining cell populations and compartments. We compared Panx1 expression over the cerebellum, hippocampus with adjacent cortex, thalamus, and olfactory bulb. While Panx1 localizes to the same neuronal cell types, subcellular localizations differ. Two antibodies with epitopes against the intracellular loop and one against the carboxy terminus preferentially labeled cell bodies, while an antibody raised against an N-terminal peptide highlighted neuronal processes more than cell bodies. These labeling patterns may be a reflection of different cellular and subcellular localizations of full-length and/or modified Panx1 channels where each antibody is highlighting unique or differentially accessible Panx1 populations. However, we cannot rule out that one or more of these antibodies have specificity issues. All data associated with experiments from these four antibodies are presented in a manner that allows them to be compared and our claims thoroughly evaluated, rather than eliminating results that were questionable. Each antibody is given a unique identifier through the NIF Antibody Registry that can be used to track usage of individual antibodies across papers and all image and metadata are made available in the public repository, the Cell Centered Database, for on-line viewing, and download.
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Affiliation(s)
- Angela C Cone
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA
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25
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Iacobas S, Iacobas DA, Spray DC, Scemes E. The connexin43-dependent transcriptome during brain development: importance of genetic background. Brain Res 2012; 1487:131-9. [PMID: 22771707 PMCID: PMC3501561 DOI: 10.1016/j.brainres.2012.05.062] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 05/31/2012] [Indexed: 01/27/2023]
Abstract
Use of null mutant mice is a powerful way to evaluate the role of specific proteins in brain function. Studies performed on knockout mice have revealed some unexpected roles of the gap junction proteins (connexins). Thus, analyses of gene expression in connexin43 (Cx43) null brains indicated that deletion of a single gene (Gja1) induced expression level change of numerous other genes located on all chromosomes and involved in a wide diversity of functional pathways. The significant overlap between alterations in gene expression level, control and coordination in Cx43 knockout and knockdown astrocytes raised the possibility that Gja1 represents a transcriptomic node of gene regulatory networks. However, conditional deletion of Gja1 in astrocytes of two mouse strains resulted in remarkably different phenotypes. In order to evaluate the influence of the genetic background on the transcriptome, we performed microarray studies on brains of GFAP-Cre:Cx43(f/f) C57Bl/6 and 129/SvEv mice. The surprisingly low number of Cx43 core genes (regulated in all Cx43 nulls regardless of strain) and the high number of differently regulated genes in the two Cx43 conditional knockouts indicate high influence of mouse strain on brain transcriptome. This article is part of a Special Issue entitled Electrical Synapses.
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Affiliation(s)
- S Iacobas
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1410, Pelham Parkway, Kennedy Center, Room 203, Bronx, NY 10461, USA
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26
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Suadicani SO, Iglesias R, Wang J, Dahl G, Spray DC, Scemes E. ATP signaling is deficient in cultured Pannexin1-null mouse astrocytes. Glia 2012; 60:1106-16. [PMID: 22499153 DOI: 10.1002/glia.22338] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 03/16/2012] [Indexed: 11/11/2022]
Abstract
Pannexins (Panx1, 2, and 3) comprise a group of proteins expressed in vertebrates that share weak yet significant sequence homology with the invertebrate gap junction proteins, the innexins. In contrast to the other vertebrate gap junction protein family (connexin), pannexins do not form intercellular channels, but at least Panx1 forms nonjunctional plasma membrane channels. Panx1 is ubiquitously expressed and has been shown to form large conductance (500 pS) channels that are voltage dependent, mechanosensitive, and permeable to relatively large molecules such as ATP. Pharmacological and knockdown approaches have indicated that Panx1 is the molecular substrate for the so-called "hemichannel" originally attributed to connexin43 and that Panx1 is the pore-forming unit of the P2X(7) receptor. Here, we describe, for the first time, conductance and permeability properties of Panx1-null astrocytes. The electrophysiological and fluorescence imaging analyses performed on these cells fully support our previous pharmacological and Panx1 knockdown studies that showed profoundly lower dye uptake and ATP release than wild-type untreated astrocytes. As a consequence of decreased ATP paracrine signaling, intercellular calcium wave spread is altered in Panx1-null astrocytes. Moreover, we found that in astrocytes as in Panx1-expressing oocytes, elevated extracellular K(+) activates Panx1 channels independently of membrane potential. Thus, on the basis of our present findings and our previous report, we propose that Panx1 channels serve as K(+) sensors for changes in the extracellular milieu such as those occurring under pathological conditions.
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Affiliation(s)
- Sylvia O Suadicani
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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27
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Scemes E, Spray DC. Extracellular K⁺ and astrocyte signaling via connexin and pannexin channels. Neurochem Res 2012; 37:2310-6. [PMID: 22481627 DOI: 10.1007/s11064-012-0759-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/09/2012] [Accepted: 03/21/2012] [Indexed: 10/28/2022]
Abstract
Astrocytes utilize two major pathways to achieve long distance intercellular communication. One pathway involves direct gap junction mediated signal transmission and the other consists of release of ATP through pannexin channels and excitation of purinergic receptors on nearby cells. Elevated extracellular potassium to levels occurring around hyperactive neurons affects both gap junction and pannexin1 channels. The action on Cx43 gap junctions is to increase intercellular coupling for a period that long outlasts the stimulus. This long term increase in coupling, termed "LINC", is mediated through calcium and calmodulin dependent activation of calmodulin dependent kinase (CaMK). Pannexin1 can be activated by elevations in extracellular potassium through a mechanism that is quite different. In this case, potassium shifts activation potentials to more physiological range, thereby allowing channel opening at resting or slightly depolarized potentials. Enhanced activity of both these channel types by elevations in extracellular potassium of the magnitude occurring during periods of high neuronal activity likely has profound effects on intercellular signaling among astrocytes in the nervous system.
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Affiliation(s)
- Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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28
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Qiu F, Wang J, Spray DC, Scemes E, Dahl G. Two non-vesicular ATP release pathways in the mouse erythrocyte membrane. FEBS Lett 2011; 585:3430-5. [PMID: 21983290 DOI: 10.1016/j.febslet.2011.09.033] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 09/22/2011] [Indexed: 02/01/2023]
Abstract
Erythrocytes are exceptionally suited for analysis of non-exocytotic release mechanisms of ATP, because these cells under physiological conditions lack vesicles. Previous studies have indicated, that Pannexin1 (Panx1) provides a key ATP permeation pathway in many cell types, including human and frog erythrocytes. Here we show that erythrocytes of Panx1(-/-) mice lend further support to this conclusion. However, ATP release, although attenuated, was still observed in Panx1(-/-) mouse erythrocytes. In contrast to Panx1(+/+) cells, this release was not correlated with uptake of extracellularly applied dyes, was insensitive to Panx1 channel blockers, and was inhibited by dipyridamole and stimulated by iloprost. Thus, in erythrocytes, two independent pathways mediate the release of ATP. We also show that glyburide is a strong inhibitor of Panx1 channels.
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Affiliation(s)
- Feng Qiu
- Department of Physiology and Biophysics, University of Miami, School of Medicine, 1600 NW 10th Ave, Miami, FL 33136, USA
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29
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Scemes E. Nature of plasmalemmal functional "hemichannels". Biochim Biophys Acta 2011; 1818:1880-3. [PMID: 21703226 DOI: 10.1016/j.bbamem.2011.06.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/04/2011] [Accepted: 06/07/2011] [Indexed: 12/28/2022]
Abstract
The molecular identity of the protein forming "hemichannels" at non-junctional membranes is disputed. The family of gap junction proteins, innexins, connexins, and pannexins share several common features, including permeability characteristics and sensitivity to blocking agents. Such overlap in properties renders the identification of which of these protein species actually establishes the non-junctional membrane conductance and permeability quite complicated, especially because in vertebrates pannexins and connexins have largely overlapping distributions in tissues. Recently, attempts to establish criteria to identify events that are "hemichannel" mediated and those to allow the distinction between connexin- from pannexin-mediated events have been proposed. Here, I present an update on that topic and discuss the most recent findings related to the nature of functional "hemichannels" focusing on connexin43 and pannexin1. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Affiliation(s)
- Eliana Scemes
- Dominick P.Purpura Department of Neuroscience, Albert Einstein Collegeof Medicine, Bronx, NY, USA.
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30
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Sosinsky GE, Boassa D, Dermietzel R, Duffy HS, Laird DW, MacVicar B, Naus CC, Penuela S, Scemes E, Spray DC, Thompson RJ, Zhao HB, Dahl G. Pannexin channels are not gap junction hemichannels. Channels (Austin) 2011; 5:193-7. [PMID: 21532340 DOI: 10.4161/chan.5.3.15765] [Citation(s) in RCA: 268] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Pannexins, a class of membrane channels, bear significant sequence homology with the invertebrate gap junction proteins, innexins and more distant similarities in their membrane topologies and pharmacological sensitivities with the gap junction proteins, connexins. However, the functional role for the pannexin oligomers, or pannexons, is different from connexin oligomers, the connexons. Many pannexin publications have used the term "hemichannels" to describe pannexin oligomers while others use the term "channels" instead. This has led to confusion within the literature about the function of pannexins that promotes the idea that pannexons serve as gap junction hemichannels and thus have an assembly and functional state as gap junctional intercellular channels. Here we present the case that unlike the connexin gap junction intercellular channels, so far, pannexin oligomers have repeatedly been shown to be channels that are functional in single membranes, but not as intercellular channel in appositional membranes. Hence, they should be referred to as channels and not hemichannels. Thus, we advocate that in the absence of firm evidence that pannexins form gap junctions, the use of the term "hemichannel" be discontinued within the pannexin literature.
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Affiliation(s)
- Gina E Sosinsky
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA.
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31
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Abstract
The authors' laboratory has reported potent block of Pannexin1 (Panx1) currents by the antimalarial quinine derivative mefloquine. However, other laboratories have found little or no mefloquine sensitivity of Panx1 currents or processes attributable to these channels. In order to resolve this issue, the authors have performed extensive dose-response studies on Panx1-transfected neuroblastoma (Neuro2A) and rat insulinoma (Rin) cells, comparing mefloquine obtained from three suppliers and also comparing the sensitivity to diastereomers. Results indicate a 20-fold difference in sensitivity to the (-)-threo-(11R/2R) diastereomer compared to the erythro enatiomers and much lower potency of (+/-)-erythro-(R*/S*)-mefloquine obtained from one of the commercial sources. This markedly lower efficacy presumably accounts for the disparity in results from different laboratories who have applied it in Panx1 studies.
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Affiliation(s)
- Rodolfo Iglesias
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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32
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Santiago MF, Alcami P, Striedinger KM, Spray DC, Scemes E. The carboxyl-terminal domain of connexin43 is a negative modulator of neuronal differentiation. J Biol Chem 2010; 285:11836-45. [PMID: 20164188 DOI: 10.1074/jbc.m109.058750] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Connexin43 (Cx43) is widely expressed in embryonic brain, and its expression becomes restricted mainly to astrocytes as the central nervous system matures. Recent studies have indicated that Cx43 plays important, nonchannel, roles during central nervous system development by affecting neuronal cell migration. Here, we evaluated the effects of Cx43 on neuronal differentiation. For that we used an in vitro model of neural cell development (neurospheres) to evaluate, through immunocytochemistry, electrophysiology, and molecular biology, the degree of neuronal maturation from neurospheres derived from wild-type (WT) and Cx43-null mice. Our results indicate that Cx43 is a negative modulator of neuronal differentiation. The percent neurospheres containing differentiated neurons and the number of cells displaying inward currents were significantly higher in Cx43-null than in WT littermate neurospheres. Knockdown of Cx43 with small interfering RNA increased the number of WT neurospheres generating differentiated neurons. Blockade of gap junctional communication with carbenoxolone did not induce neuronal differentiation in WT neurospheres. Transfection of Cx43-null neurospheres with Cx43 mutants revealed that Cx43 carboxyl terminus prevents neuronal maturation. In agreement with these in vitro data, in situ analysis of embryonic day 16 brains revealed increased beta-III-tubulin expression in germinal zones of Cx43-null compared with that of WT littermates. These results indicate that Cx43, and specifically its carboxyl terminus, is crucial for signaling mechanisms preventing premature neuronal differentiation during embryonic brain development.
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Affiliation(s)
- Marcelo F Santiago
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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33
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Silverman WR, de Rivero Vaccari JP, Locovei S, Qiu F, Carlsson SK, Scemes E, Keane RW, Dahl G. The pannexin 1 channel activates the inflammasome in neurons and astrocytes. J Biol Chem 2009; 284:18143-51. [PMID: 19416975 DOI: 10.1074/jbc.m109.004804] [Citation(s) in RCA: 424] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The inflammasome is a multiprotein complex involved in innate immunity. Activation of the inflammasome causes the processing and release of the cytokines interleukins 1beta and 18. In primary macrophages, potassium ion flux and the membrane channel pannexin 1 have been suggested to play roles in inflammasome activation. However, the molecular mechanism(s) governing inflammasome signaling remains poorly defined, and it is undetermined whether these mechanisms apply to the central nervous system. Here we show that high extracellular potassium opens pannexin channels leading to caspase-1 activation in primary neurons and astrocytes. The effect of K(+) on pannexin 1 channels was independent of membrane potential, suggesting that stimulation of inflammasome signaling was mediated by an allosteric effect. The activation of the inflammasome by K(+) was inhibited by the pannexin 1 channel blocker probenecid, supporting a role of pannexin 1 in inflammasome activation. Co-immunoprecipitation of neuronal lysates indicates that pannexin 1 associates with components of the multiprotein inflammasome complex, including the P2X7 receptor and caspase-1. Moreover antibody neutralization of the adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD) blocked ATP-induced cell death in oocytes co-expressing P2X7 receptor and pannexin 1. Thus, in contrast to macrophages and monocytes in which low intracellular K(+) has been suggested to trigger inflammasome activation, in neural cells, high extracellular K(+) activates caspase-1 probably through pannexin 1.
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Affiliation(s)
- William R Silverman
- Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, Florida 33136, USA
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34
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Scemes E, Spray DC, Meda P. Connexins, pannexins, innexins: novel roles of "hemi-channels". Pflugers Arch 2008; 457:1207-26. [PMID: 18853183 DOI: 10.1007/s00424-008-0591-5] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Accepted: 09/17/2008] [Indexed: 12/11/2022]
Affiliation(s)
- Eliana Scemes
- The Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA
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35
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Abstract
Connexins and pannexins have been implicated in the formation of "hemichannels," which may account for the uptake and release of membrane-impermeant molecules in single cells. The in vivo existence of "hemichannels" and their protein composition is still debated. Investigations on these matters are complicated by the lack of adequate negative controls. In search for such essential controls, the authors have investigated transformed (MIN6 line) and primary insulin-producing cells. Here, the authors report that these cells, which express Cx36 and pannexin 1, cannot be shown to display functional "hemichannels," as evaluated by (1) uptake of the membrane-impermeant tracer ethidium bromide, whether in the presence or absence of extracellular Ca(2+), following stimulation of P2X(7) receptors, and after exposure to hypotonic medium; and (2) lack of exocytosis-independent release of endogenous ATP. Moreover, electrophysiological recordings indicated the absence of carbenoxolone-sensitive pannexin 1 currents evoked by membrane potentials above +30 mV. Thus, insulin-producing cells are expected to provide a useful tool in the further characterization of hemichannel composition, properties, and physiological relevance.
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Affiliation(s)
- Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
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36
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Iacobas DA, Iacobas S, Urban-Maldonado M, Scemes E, Spray DC. Similar transcriptomic alterations in Cx43 knockdown and knockout astrocytes. ACTA ACUST UNITED AC 2008; 15:195-206. [PMID: 18649190 DOI: 10.1080/15419060802014222] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Previous findings of widespread transcriptomic alteration in tissues from connexin null mice raise the issue of whether the transcriptomic changes are directly due to connexin down-regulation or to "compensatory" developmental alterations for the missing gene. To start addressing this question, the authors compared with wild-type control the gene expression profiles of connexin 43 (Cx43) knockout and Cx43siRNA knockdown wild-type cortical astrocytes. Array analysis revealed remarkable parallelism of transcriptomic changes in knockout and knockdown astrocytes, with similarly altered genes being located on all chromosomes and encoding proteins involved in a wide diversity of cell functions. Moreover, gene expression variability was analogously higher in Cx43 null and siRNA-treated astrocytes, and expression interlinkages were similarly altered among a selected subset of genes. This highly significant overlap between transcriptomic alterations in Cx43 knockout and knockdown astrocytes suggests that the widespread changes more likely reflect connexin-dependent Gene Regulatory Networks rather than developmental compensation for the missing gene.
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Affiliation(s)
- Dumitru A Iacobas
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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37
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Iglesias R, Locovei S, Roque A, Alberto AP, Dahl G, Spray DC, Scemes E. P2X7 receptor-Pannexin1 complex: pharmacology and signaling. Am J Physiol Cell Physiol 2008; 295:C752-60. [PMID: 18596211 DOI: 10.1152/ajpcell.00228.2008] [Citation(s) in RCA: 277] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pannexin 1 (Panx1), an ortholog to invertebrate innexin gap junctions, has recently been proposed to be the pore induced by P2X(7) receptor (P2X(7)R) activation. We explored the pharmacological action of compounds known to block gap junctions on Panx1 channels activated by the P2X(7)R and the mechanisms involved in the interaction between these two proteins. Whole cell recordings revealed distinct P2X(7)R and Panx1 currents in response to agonists. Activation of Panx1 currents following P2X(7)R stimulation or by membrane depolarization was blocked by Panx1 small-interfering RNA (siRNA) and with mefloquine > carbenoxolone > flufenamic acid. Incubation of cells with KN-62, a P2X(7)R antagonist, prevented current activation by 2'(3')-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate (BzATP). Membrane permeabilization to dye induced by BzATP was also prevented by Panx1 siRNA and by carbenoxolone and mefloquine. Membrane permeant (TAT-P2X(7)) peptides, provided evidence that the Src homology 3 death domain of the COOH-terminus of the P2X(7)R is involved in the initial steps of the signal transduction events leading to Panx1 activation and that a Src tyrosine kinase is likely involved in this process. Competition assays indicated that 20 microM TAT-P2X(7) peptide caused 50% reduction in Src binding to the P2X(7)R complex. Src tyrosine phosphorylation following BzATP stimulation was reduced by KN-62, TAT-P2X(7) peptide, and by the Src tyrosine inhibitor PP2 and these compounds prevented both large-conductance Panx1 currents and membrane permeabilization. These results together with the lack Panx1 tyrosine phosphorylation in response to P2X(7)R stimulation indicate the involvement of an additional molecule in the tyrosine kinase signal transduction pathway mediating Panx1 activation through the P2X(7)R.
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Affiliation(s)
- R Iglesias
- The Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
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Striedinger K, Scemes E. Interleukin-1beta affects calcium signaling and in vitro cell migration of astrocyte progenitors. J Neuroimmunol 2008; 196:116-23. [PMID: 18462808 DOI: 10.1016/j.jneuroim.2008.03.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Revised: 03/05/2008] [Accepted: 03/24/2008] [Indexed: 01/19/2023]
Abstract
Spontaneous calcium activity of neural progenitors is largely dependent on a paracrine signaling mechanism involving release of ATP and activation of purinergic receptors. Although it is well documented that, in mature astrocytes, cytokines modulate the expression levels of certain purinergic receptors, nothing is known about their impact during early stages of development. Here we provide evidence that conditioned medium from activated microglia and interleukin-1beta, but not tumor necrosis factor-alpha, decrease the frequency of calcium oscillations and reduce the rate of in vitro migration of astrocyte progenitors. Such alterations were due to changes in activity of two purinergic P2 receptors, and not to the amount of released ATP. These results indicate that interleukin-1beta plays an important role during early stages of CNS development, modulating calcium signaling and cell migration.
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Affiliation(s)
- Katharine Striedinger
- The Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Abstract
Gap junction proteins, connexins, provide intercellular channels that allow ions and small signaling molecules to be transmitted to adjacent coupled cells. Besides this function, it is becoming apparent that connexins also exert channel-independent effects, which are likely mediated by processes involving protein-protein interactions. Although a number of connexin interacting proteins have been identified, only little is known about the functional consequences of such interactions. We have previously shown that deletion of the astrocytic gap junction protein, connexin43 (Cx43) causes a right-ward shift in the dose-response curve to P2Y1R agonists and decreased P2Y1R expression levels. To evaluate whether these changes were due to reduced gap junctional communication or to protein-protein interactions, Cx43-null astrocytes were transfected with full-length Cx43 and Cx43 domains, and P2Y1R function and expression levels evaluated. Results indicate that restoration of P2Y1R function is independent of gap junctional communication and that the Cx43 carboxyl terminus spanning the SH3 binding domain (260-280) participates in the rescue of P2Y1R pharmacological behavior (shifting to the left the P2Y1R dose-response curve) without affecting its expression levels. These results suggest that the Cx43 carboxyl-terminus domain provides a binding site for an intracellular molecule, most likely a member of the c-Src tyrosine kinase family, which affects P2Y1R-induced calcium mobilization. It is here proposed that a nonchannel function of Cx43 is to serve as a decoy for such kinases. Such modulation of P2Y1R is expected to influence several neural cell functions, especially under inflammation and neurodegenerative disorders where expression levels of Cx43 are decreased.
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Affiliation(s)
- Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine. Bronx, New York 10461, USA.
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Iacobas DA, Iacobas S, Werner P, Scemes E, Spray DC. Alteration of transcriptomic networks in adoptive-transfer experimental autoimmune encephalomyelitis. Front Integr Neurosci 2007; 1:10. [PMID: 18958238 PMCID: PMC2526015 DOI: 10.3389/neuro.07.010.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Accepted: 12/03/2007] [Indexed: 01/09/2023] Open
Abstract
Adoptive transfer experimental autoimmune encephalomyelitis (AT-EAE) is an inflammatory demyelination that recapitulates in mouse spinal cord (SC) the human multiple sclerosis disease. We now analyze previously reported cDNA array data from age-matched young female adult control and passively myelin antigen-sensitized EAE mice with regard to organizational principles of the SC transcriptome in autoimmune demyelination. Although AT-EAE had a large impact on immune response genes, broader functional and chromosomal gene cohorts were neither significantly regulated nor showed significant changes in expression coordination. However, overall transcriptional control was increased in AT-EAE and the proportions of transcript abundances were perturbed within each cohort. Striking likenesses and oppositions were identified in the coordination profiles of genes related to myelination, calcium signaling, and inflammatory response in controls that were substantially altered in AT-EAE. We propose that up- or down-regulation of genes linked to those targeted by the disease could potentially compensate for the pathological transcriptomic changes.
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Affiliation(s)
- Dumitru A Iacobas
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine USA.
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Iacobas DA, Suadicani SO, Iacobas S, Chrisman C, Cohen MA, Spray DC, Scemes E. Gap junction and purinergic P2 receptor proteins as a functional unit: insights from transcriptomics. J Membr Biol 2007; 217:83-91. [PMID: 17665085 DOI: 10.1007/s00232-007-9039-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Accepted: 05/14/2007] [Indexed: 10/23/2022]
Abstract
Gap junctions and purinergic P2 receptors (P2Rs) can be regarded as belonging to a common functional unit, given that they are involved in the transmission of calcium signals between cells. We have previously shown that deletion of the Gja1 gene alters expression levels of numerous genes encoding proteins with diverse functions, including purinergic receptors (P2Rs), and have found that genes synergistically or antagonistically expressed in wild-type tissues are more prone to be similarly or oppositely regulated in Cx43-nulls. We have now explored the use of coordination analysis of gene expression as a strategy to identify interlinked genes encoding functionally related proteins and pull-downs to evaluate their interlinkage. Our findings indicate that, in brain and in cultured astrocytes, several of these coexpressed genes encode proteins that are components of P2R signal-transduction pathways and/or directly interact with these receptors, including the gap junction protein connexin43 (Cx43) and Cx45 as well as pannexins. It is proposed that coordination analysis of gene expression may provide a novel unbiased strategy for the identification of proteins belonging to supramolecular complexes.
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Affiliation(s)
- Dumitru A Iacobas
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Mouneimne G, DesMarais V, Sidani M, Scemes E, Wang W, Song X, Eddy R, Condeelis J. Spatial and temporal control of cofilin activity is required for directional sensing during chemotaxis. Curr Biol 2007; 16:2193-205. [PMID: 17113383 DOI: 10.1016/j.cub.2006.09.016] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 08/23/2006] [Accepted: 09/06/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND Previous work has led to the hypothesis that cofilin severing, as regulated by PLC, is involved in chemotactic sensing. We have tested this hypothesis by investigating whether activation of endogenous cofilin is spatially and temporally linked to sensing an EGF point source in carcinoma cells. RESULTS We demonstrate that inhibition of endogenous cofilin activity with either siRNA or overexpression of LIMK suppresses directional sensing in carcinoma cells. LIMK siRNA knockdown, which suppresses cofilin phosphorylation, and microinjection of S3C cofilin, a cofilin mutant that is constitutively active and not phosphorylated by LIMK, also inhibits directional sensing and chemotaxis. These results indicate that phosphorylation of cofilin by LIMK, in addition to cofilin activity, is required for chemotaxis. Cofilin activity concentrates rapidly at the newly formed leading edge facing the gradient, whereas cofilin phosphorylation increases throughout the cell. Quantification of these results indicates that the amplification of asymmetric actin polymerization required for protrusion toward the EGF gradient occurs at the level of cofilin but not at the level of PLC activation by EGFR. CONCLUSIONS These results indicate that local activation of cofilin by PLC and its global inactivation by LIMK phosphorylation combine to generate the local asymmetry of actin polymerization required for chemotaxis.
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Affiliation(s)
- Ghassan Mouneimne
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA.
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Locovei S, Scemes E, Qiu F, Spray DC, Dahl G. Pannexin1 is part of the pore forming unit of the P2X(7) receptor death complex. FEBS Lett 2007; 581:483-8. [PMID: 17240370 PMCID: PMC1868681 DOI: 10.1016/j.febslet.2006.12.056] [Citation(s) in RCA: 358] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Revised: 12/18/2006] [Accepted: 12/22/2006] [Indexed: 11/28/2022]
Abstract
The purinergic receptor P2X(7) is part of a complex signaling mechanism participating in a variety of physiological and pathological processes. Depending on the activation scheme, P2X(7) receptors in vivo are non-selective cation channels or form large pores that can mediate apoptotic cell death. Expression of P2X(7)R in Xenopus oocytes results exclusively in formation of a non-selective cation channel. However, here we show that co-expression of P2X(7)R with pannexin1 in oocytes leads to the complex response seen in many mammalian cells, including cell death with prolonged ATP application. While the cation channel activity is resistant to carbenoxolone treatment, this gap junction and hemichannel blocking drug suppressed the currents induced by ATP in pannexin1/P2X(7)R co-expressing cells. Thus, pannexin1 appears to be the molecular substrate for the permeabilization pore (or death receptor channel) recruited into the P2X(7)R signaling complex.
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Affiliation(s)
- Silviu Locovei
- Department of Physiology and Biophysics, University of Miami School of Medicine,1600 NW 10th Ave, Miami, FL 33136, USA
| | - Eliana Scemes
- The Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Feng Qiu
- Department of Physiology and Biophysics, University of Miami School of Medicine,1600 NW 10th Ave, Miami, FL 33136, USA
| | - David C. Spray
- The Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Gerhard Dahl
- Department of Physiology and Biophysics, University of Miami School of Medicine,1600 NW 10th Ave, Miami, FL 33136, USA
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Zhao Y, Rivieccio MA, Lutz S, Scemes E, Brosnan CF. The TLR3 ligand polyI: C downregulates connexin 43 expression and function in astrocytes by a mechanism involving the NF-kappaB and PI3 kinase pathways. Glia 2007; 54:775-85. [PMID: 16958087 PMCID: PMC2701309 DOI: 10.1002/glia.20418] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Toll-like receptor 3 (TLR3) is a component of the innate immune response that responds to dsRNA viruses and virus replication intermediates. In this study we show that activation of astrocytes with the dsRNA mimetic polyinosinic-cytidylic acid (pI:C) results in loss of expression of connexin43 (Cx43) mRNA and protein while upregulating the expression of the ionotropic P2 receptor P2X(4)R. Analysis of the signaling pathways involved failed to demonstrate a role for the p38 MAP kinase, ERK, or JNK signaling pathways whereas an inhibitor of the PI3 kinase/Akt pathway effectively blocked the action of pI:C. Using adenoviral vectors containing a super-repressor of NF-kappaB (NF-kappaB SR) construct or a dominant negative interferon regulatory factor 3 (dnIRF3) construct showed that inhibition of both transcription factors also blocked the effects of pI:C. To explore the functional consequences of pI:C activation we used a pore-forming assay for P2X(4)R activity and a scrape loading assay for gap junction intercellular communication (GJIC). No pore-forming activity consistent with functional P2X(4)R expression was detected in either control or activated astrocytes. In contrast, robust Lucifer yellow transfer indicative of GJIC was detected in resting cells that was lost following pI:C activation. The dnIRF3 construct failed to restore GJIC whereas the NF-kappaB SR or the NF-kappaB inhibitor BAY11-7082 and the PI3K inhibitor LY294002 all significantly reversed the effect of pI:C on GJ connectivity. We conclude that activation of the innate immune response in astrocytes is associated with functional loss of GJIC through a pathway involving NF-kappaB and PI3 kinase.
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Affiliation(s)
- Yongmei Zhao
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10464, USA
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Affiliation(s)
| | - Ken D McCarthy
- Department of Pharmacology, University of North Carolina, Chapel Hill, N.C., U.S.A
| | - Eliana Scemes
- Department of Neuroscience, Albert Einstein College, New York, U.S.A
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Abstract
Several lines of evidence indicate that the elaborated calcium signals and the occurrence of calcium waves in astrocytes provide these cells with a specific form of excitability. The identification of the cellular and molecular steps involved in the triggering and transmission of Ca(2+) waves between astrocytes resulted in the identification of two pathways mediating this form of intercellular communication. One of them involves the direct communication between the cytosols of two adjoining cells through gap junction channels, while the other depends upon the release of "gliotransmitters" that activates membrane receptors on neighboring cells. In this review we summarize evidence in favor of these two mechanisms of Ca(2+) wave transmission and we discuss that they may not be mutually exclusive, but are likely to work in conjunction to coordinate the activity of a group of cells. To address a key question regarding the functional consequences following the passage of a Ca(2+) wave, we list, in this review, some of the potential intracellular targets of these Ca(2+) transients in astrocytes, and discuss the functional consequences of the activation of these targets for the interactions that astrocytes maintain with themselves and with other cellular partners, including those at the glial/vasculature interface and at perisynaptic sites where astrocytic processes tightly interact with neurons.
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Affiliation(s)
- Eliana Scemes
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
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47
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Abstract
Modulation of synaptic transmission and brain microcirculation are new roles ascribed to astrocytes in CNS function. A mechanism by which astrocytes modify neuronal activity in the healthy brain depends on fluctuations of cytosolic Ca2+ levels, which regulate the release of "gliotransmitters" via an exocytic pathway. Under pathological conditions, however, the participation of other pathways, including connexin hemichannels and the pore-forming P2X7R, have been proposed but remain controversial. Through the use of genetically modified 1321N1 human astrocytoma cells and of spinal cord astrocytes derived from neonatal Cx43- and P2X7R-null mice, we provide strong evidence that P2X7Rs, but not Cx43 hemichannels, are sites of ATP release that promote the amplification of Ca2+ signal transmission within the astrocytic network after exposure to low divalent cation solution. Moreover, our results showing that gap junction channel blockers (heptanol, octanol, carbenoxolone, flufenamic acid, and mefloquine) are antagonists of the P2X7R indicate the inadequacy of using these compounds as evidence for the participation of connexin hemichannels as sites of gliotransmitter release.
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Affiliation(s)
- Sylvia O Suadicani
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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Dobrenis K, Chang HY, Pina-Benabou MH, Woodroffe A, Lee SC, Rozental R, Spray DC, Scemes E. Human and mouse microglia express connexin36, and functional gap junctions are formed between rodent microglia and neurons. J Neurosci Res 2005; 82:306-15. [PMID: 16211561 PMCID: PMC2583240 DOI: 10.1002/jnr.20650] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Microglia, the tissue macrophages of the central nervous system (CNS), intimately interact with neurons physically and through soluble factors that can affect microglial activation state and neuronal survival and physiology. We report here a new mechanism of interaction between these cells, provided by the formation of gap junctions composed of connexin (Cx) 36. Among eight Cxs tested, expression of Cx36 mRNA and protein was found in microglial cultures prepared from human and mouse, and Cx45 mRNA was found in mouse microglial cultures. Electrophysiological measurements found coupling between one-third of human or mouse microglial pairs that averaged below 30 pico-Siemens and displayed electrical properties consistent with Cx36 gap junctions. Importantly, similar frequency of low-strength electrical coupling was also obtained between microglia and neurons in cocultures prepared from neocortical or hippocampal rodent tissue. Lucifer yellow dye coupling between neurons and microglia was observed in 4% of pairs tested, consistent with the low strength and incidence of electrical coupling. Cx36 expression level and/or the degree of coupling between microglia did not significantly change in the presence of activating agents, including lipopolysaccharide, granulocyte-macrophage colony-stimulating factor, interferon-gamma, and tumor necrosis factor-alpha, except for some reduction of Cx36 protein when exposed to the latter two agents. Our findings that intercellular coupling occurs between neuronal and microglial populations through Cx36 gap junctions have potentially important implications for normal neural physiology and microglial responses in neuronopathology in the mammalian CNS.
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Affiliation(s)
- K Dobrenis
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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Abstract
We describe a two-dimensional stochastic model of intercellular Ca(2+) wave (ICW) spread in glia that includes contributions of external stimuli, ionotropic and metabotropic P2 receptors, exo- and ecto-nucleotidases, second messengers, and gap junctions. In this model, an initial stimulus evokes ATP and UTP release from a single cell. Agonists diffuse and are degraded both in bulk solution and at cell surfaces. Ca(2+) elevation in individual cells is determined by bound agonist concentrations s and by number and features of P2 receptors summed with that generated by IP(3) diffusing through gap junction channels. Variability of ICWs is provided by randomly distributing a predetermined density of cells in a rectangular grid and by randomly selecting within intervals values characterizing the extracellular compartment, individual cells, and interconnections with neighboring cells. Variability intervals were obtained from experiments on astrocytoma cells transfected to express individual P2 receptors and/or the gap junction protein connexin43. The simulation program (available as Supplementary Material) permits individual alteration of ICW components, allowing comparison of simulations with data from cells expressing connexin43 and/or various P2 receptor subtypes. Such modeling is expected to be useful for testing phenomenological hypotheses and in understanding consequences of alteration of system components under experimental or pathological conditions.
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Affiliation(s)
- Dumitru A Iacobas
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA.
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Brand-Schieber E, Werner P, Iacobas DA, Iacobas S, Beelitz M, Lowery SL, Spray DC, Scemes E. Connexin43, the major gap junction protein of astrocytes, is down-regulated in inflamed white matter in an animal model of multiple sclerosis. J Neurosci Res 2005; 80:798-808. [PMID: 15898103 PMCID: PMC1226319 DOI: 10.1002/jnr.20474] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Both multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), its animal model, involve inflammatory attack on central nervous system (CNS) white matter, leading to demyelination and axonal damage. Changes in astrocytic morphology and function are also prominent features of MS and EAE. Resting astrocytes form a network that is interconnected through gap junctions, composed mainly of connexin43 (Cx43) protein. Although astrocytic gap junctional connectivity is known to be altered in many CNS pathologies, little is known about Cx43 expression in inflammatory demyelinating disease. Therefore, we evaluated the expression of Cx43 in spinal cords of EAE mice compared with healthy controls. Lumbar ventral white matter areas were heavily infiltrated with CD11beta-immunoreactive monocytes, and within these infiltrated regions loss of Cx43 immunoreactivity was evident. These regions also showed axonal dystrophy, demonstrated by the abnormally dephosphorylated heavy-chain neurofilament proteins. Astrocytes in these Cx43-depleted lesions were strongly glial fibrillary acidic protein reactive. Significant loss (38%) of Cx43 protein in EAE mouse at the lumbar portion of spinal cords was confirmed by Western blot analysis. Decreased Cx43 transcript level was also observed on cDNA microarray analysis. In addition to changes in Cx43 expression, numerous other genes were altered, including those encoding adhesion and extracellular matrix proteins. Our data support the notion that, in addition to damage of myelinating glia, altered astrocyte connectivity is a prominent feature of inflammatory demyelination.
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