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Huang Y, Shi Y, Wang M, Liu B, Chang X, Xiao X, Yu H, Cui X, Bai Y. Pannexin1 Channel-Mediated Inflammation in Acute Ischemic Stroke. Aging Dis 2024; 15:1296-1307. [PMID: 37196132 PMCID: PMC11081155 DOI: 10.14336/ad.2023.0303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/03/2023] [Indexed: 05/19/2023] Open
Abstract
Emerging evidence suggests that inflammation mediated by the pannexin1 channel contributes significantly to acute ischemic stroke. It is believed that the pannexin1 channel is key in initiating central system inflammation during the early stages of acute ischemic stroke. Moreover, the pannexin1 channel is involved in the inflammatory cascade to maintain the inflammation levels. Specifically, the interaction of pannexin1 channels with ATP-sensitive P2X7 purinoceptors or promotion of potassium efflux mediates the activation of the NLRP3 inflammasome, triggering the release of pro-inflammatory factors such as IL-1 and IL-18, exacerbating and sustaining inflammation of brain. Also, increased release of ATP induced by cerebrovascular injury activates pannexin1 in vascular endothelial cells. This signal directs peripheral leukocytes to migrate into ischemic brain tissue, leading to an expansion of the inflammatory zone. Intervention strategies targeting pannexin1 channels may greatly alleviate inflammation after acute ischemic stroke to improve this patient population's clinical outcomes. In this review, we sought to summarize relevant studies on inflammation mediated by the pannexin1 channel in acute ischemic stroke and discussed the possibility of using brain organoid-on-a-chip technology to screen miRNAs that exclusively target the pannexin1 channel to provide new therapeutic measures for targeted regulation of pannexin1 channel to reduce inflammation in acute ischemic stroke.
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Affiliation(s)
- Yubing Huang
- Department of Neurology, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning, China
- Graduate School, Dalian University, Dalian, Liaoning, China
| | - Yutong Shi
- Department of Neurology, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning, China
- Graduate School, Dalian University, Dalian, Liaoning, China
| | - Mengmeng Wang
- Department of Neurology, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning, China
- Medical College, Institute of Microanalysis, Dalian University, Dalian, Liaoning, China
- Graduate School, Dalian University, Dalian, Liaoning, China
| | - Bingyi Liu
- Department of Neurology, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning, China
- Graduate School, Dalian University, Dalian, Liaoning, China
| | - Xueqin Chang
- Department of Neurology, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning, China
- Graduate School, Dalian University, Dalian, Liaoning, China
| | - Xia Xiao
- Department of Neurology, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning, China
- Graduate School, Dalian University, Dalian, Liaoning, China
| | - Huihui Yu
- Department of Neurology, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning, China
- Graduate School, Dalian University, Dalian, Liaoning, China
| | - Xiaodie Cui
- Department of Neurology, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning, China
- Graduate School, Dalian University, Dalian, Liaoning, China
| | - Ying Bai
- Department of Neurology, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning, China
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2
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Koval M, Cwiek A, Carr T, Good ME, Lohman AW, Isakson BE. Pannexin 1 as a driver of inflammation and ischemia-reperfusion injury. Purinergic Signal 2021; 17:521-531. [PMID: 34251590 PMCID: PMC8273370 DOI: 10.1007/s11302-021-09804-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/24/2021] [Indexed: 02/06/2023] Open
Abstract
Pannexin 1 (Panx1) is a ubiquitously expressed protein forming large conductance channels that are central to many distinct inflammation and injury responses. There is accumulating evidence showing ATP released from Panx1 channels, as well as metabolites, provide effective paracrine and autocrine signaling molecules that regulate different elements of the injury response. As channels with a broad range of permselectivity, Panx1 channels mediate the secretion and uptake of multiple solutes, ranging from calcium to bacterial derived molecules. In this review, we describe how Panx1 functions in response to different pro-inflammatory stimuli, focusing mainly on signaling coordinated by the vasculature. How Panx1 mediates ATP release by injured cells is also discussed. The ability of Panx1 to serve as a central component of many diverse physiologic responses has proven to be critically dependent on the context of expression, post-translational modification, interacting partners, and the mode of stimulation.
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Affiliation(s)
- Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, 205 Whitehead Building, 615 Michael Street, Atlanta, GA, 30322, USA.
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
| | - Aleksandra Cwiek
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Thomas Carr
- Department of Cell Biology and Anatomy, University of Calgary Cumming School of Medicine, Calgary, AB, Canada
- Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Miranda E Good
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA, USA
| | - Alexander W Lohman
- Department of Cell Biology and Anatomy, University of Calgary Cumming School of Medicine, Calgary, AB, Canada
- Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center, School of Medicine, University of Virginia, PO Box 801394, Charlottesville, VA, 22908, USA.
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
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3
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Sen Halicioglu B, Saadat KASM, Tuglu MI. Adipose-Derived Mesenchymal Stem Cell Transplantation in Chemotherapy-Induced Premature Ovarian Insufficiency: the Role of Connexin and Pannexin. Reprod Sci 2021; 29:1316-1331. [PMID: 34449073 DOI: 10.1007/s43032-021-00718-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 08/14/2021] [Indexed: 10/20/2022]
Abstract
In women undergoing chemotherapy, it is inevitable that infertility risk will increase because of impaired reproductive functions. Premature ovarian insufficiency (POI), which occurs as a devastating result of chemotherapy, is the complete depletion or dysfunction of ovarian follicles. Adipose-derived mesenchymal stem cells (ADMSCs) transplantation is among the alternative treatment methods for POI, which currently do not have an effective treatment method. Apoptosis of granulosa cells in POI is seen as the main mechanism of the disease. It is also reported that in addition to molecules directly associated with apoptosis, connexins, and pannexins are also potential effector molecules in apoptosis. The roles of these molecules in POI, which are known to play a role in many important mechanisms in the ovary, are unknown. In this study, it was aimed to analyze the expressions of Connexin43 and Pannexin1, which are thought to be effective in the formation of POI, and to show the relationship between the antiapoptotic effects of ADMSCs transplantation and these molecules in POI. For this purpose, Caspase3, Connexin43, Pannexin1 proteins, and mRNA expressions were analyzed by immunohistochemistry and RT-qPCR, and AMH levels were measured by ELISA. It was determined that Pannexin1, Caspase3 proteins, and mRNA levels increased in the POI, while Pannexin1 and Caspase3 expressions decreased in the ADMSCs treated group. While Connexin43 level decreased in POI, Connexin43 protein and mRNA levels increased in ADMSCs group. Consequently, this study demonstrated for the first time that Connexin43 and Pannexin1 were associated with apoptosis in POI. In addition, it was revealed that ADMSCs transplantation could produce antiapoptotic effects by modulating these molecules.
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Affiliation(s)
- Busra Sen Halicioglu
- Faculty of Medicine, Department of Histology and Embryology, Gaziantep University, Gaziantep, Turkey. .,Faculty of Medicine, Department of Histology and Embryology, Manisa Celal Bayar University, Manisa, Turkey.
| | - Khandakar A S M Saadat
- Faculty of Medicine, Department of Medical Biology, Gaziantep University, Gaziantep, Turkey
| | - Mehmet Ibrahim Tuglu
- Faculty of Medicine, Department of Histology and Embryology, Manisa Celal Bayar University, Manisa, Turkey
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4
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Purinergic signaling in nervous system health and disease: Focus on pannexin 1. Pharmacol Ther 2021; 225:107840. [PMID: 33753132 DOI: 10.1016/j.pharmthera.2021.107840] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2021] [Indexed: 02/06/2023]
Abstract
Purinergic signaling encompasses the cycle of adenosine 5' triphosphate (ATP) release and its metabolism into nucleotide and nucleoside derivatives, the direct release of nucleosides, and subsequent receptor-triggered downstream intracellular pathways. Since the discovery of nerve terminal and glial ATP release into the neuropil, purinergic signaling has been implicated in the modulation of nervous system development, function, and disease. In this review, we detail our current understanding of the roles of the pannexin 1 (PANX1) ATP-release channel in neuronal development and plasticity, glial signaling, and neuron-glial-immune interactions. We additionally provide an overview of PANX1 structure, activation, and permeability to orientate readers and highlight recent research developments. We identify areas of convergence between PANX1 and purinergic receptor actions. Additional highlights include data on PANX1's participation in the pathophysiology of nervous system developmental, degenerative, and inflammatory disorders. Our aim in combining this knowledge is to facilitate the movement of our current understanding of PANX1 in the context of other nervous system purinergic signaling mechanisms one step closer to clinical translation.
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5
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Abstract
Of the 21 members of the connexin family, 4 (Cx37, Cx40, Cx43, and Cx45) are expressed in the endothelium and/or smooth muscle of intact blood vessels to a variable and dynamically regulated degree. Full-length connexins oligomerize and form channel structures connecting the cytosol of adjacent cells (gap junctions) or the cytosol with the extracellular space (hemichannels). The different connexins vary mainly with regard to length and sequence of their cytosolic COOH-terminal tails. These COOH-terminal parts, which in the case of Cx43 are also translated as independent short isoforms, are involved in various cellular signaling cascades and regulate cell functions. This review focuses on channel-dependent and -independent effects of connexins in vascular cells. Channels play an essential role in coordinating and synchronizing endothelial and smooth muscle activity and in their interplay, in the control of vasomotor actions of blood vessels including endothelial cell reactivity to agonist stimulation, nitric oxide-dependent dilation, and endothelial-derived hyperpolarizing factor-type responses. Further channel-dependent and -independent roles of connexins in blood vessel function range from basic processes of vascular remodeling and angiogenesis to vascular permeability and interactions with leukocytes with the vessel wall. Together, these connexin functions constitute an often underestimated basis for the enormous plasticity of vascular morphology and function enabling the required dynamic adaptation of the vascular system to varying tissue demands.
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Affiliation(s)
- Ulrich Pohl
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Planegg-Martinsried, Germany; Biomedical Centre, Cardiovascular Physiology, LMU Munich, Planegg-Martinsried, Germany; German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Munich, Germany; and Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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6
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Yeung AK, Patil CS, Jackson MF. Pannexin‐1 in the CNS: Emerging concepts in health and disease. J Neurochem 2020; 154:468-485. [DOI: 10.1111/jnc.15004] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/26/2020] [Accepted: 03/09/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Albert K. Yeung
- Department of Pharmacology and Therapeutics Max Rady College of Medicine Rady Faculty of Health Sciences University of Manitoba Winnipeg Manitoba Canada
- Neuroscience Research Program Kleysen Institute for Advanced Medicine University of Manitoba Winnipeg Manitoba Canada
| | - Chetan S. Patil
- Department of Pharmacology and Therapeutics Max Rady College of Medicine Rady Faculty of Health Sciences University of Manitoba Winnipeg Manitoba Canada
- Neuroscience Research Program Kleysen Institute for Advanced Medicine University of Manitoba Winnipeg Manitoba Canada
| | - Michael F. Jackson
- Department of Pharmacology and Therapeutics Max Rady College of Medicine Rady Faculty of Health Sciences University of Manitoba Winnipeg Manitoba Canada
- Neuroscience Research Program Kleysen Institute for Advanced Medicine University of Manitoba Winnipeg Manitoba Canada
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7
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Tozzi M, Larsen AT, Lange SC, Giannuzzo A, Andersen MN, Novak I. The P2X7 receptor and pannexin-1 are involved in glucose-induced autocrine regulation in β-cells. Sci Rep 2018; 8:8926. [PMID: 29895988 PMCID: PMC5997690 DOI: 10.1038/s41598-018-27281-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 05/31/2018] [Indexed: 01/02/2023] Open
Abstract
Extracellular ATP is an important short-range signaling molecule that promotes various physiological responses virtually in all cell types, including pancreatic β-cells. It is well documented that pancreatic β-cells release ATP through exocytosis of insulin granules upon glucose stimulation. We hypothesized that glucose might stimulate ATP release through other non-vesicular mechanisms. Several purinergic receptors are found in β-cells and there is increasing evidence that purinergic signaling regulates β-cell functions and survival. One of the receptors that may be relevant is the P2X7 receptor, but its detailed role in β-cell physiology is unclear. In this study we investigated roles of the P2X7 receptor and pannexin-1 in ATP release, intracellular ATP, Ca2+ signals, insulin release and cell proliferation/survival in β-cells. Results show that glucose induces rapid release of ATP and significant fraction of release involves the P2X7 receptor and pannexin-1, both expressed in INS-1E cells, rat and mouse β-cells. Furthermore, we provide pharmacological evidence that extracellular ATP, via P2X7 receptor, stimulates Ca2+ transients and cell proliferation in INS-1E cells and insulin secretion in INS-1E cells and rat islets. These data indicate that the P2X7 receptor and pannexin-1 have important functions in β-cell physiology, and should be considered in understanding and treatment of diabetes.
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Affiliation(s)
- Marco Tozzi
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Anna T Larsen
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Sofie C Lange
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Andrea Giannuzzo
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Martin N Andersen
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ivana Novak
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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8
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Good ME, Eucker SA, Li J, Bacon HM, Lang SM, Butcher JT, Johnson TJ, Gaykema RP, Patel MK, Zuo Z, Isakson BE. Endothelial cell Pannexin1 modulates severity of ischemic stroke by regulating cerebral inflammation and myogenic tone. JCI Insight 2018; 3:96272. [PMID: 29563335 PMCID: PMC5926909 DOI: 10.1172/jci.insight.96272] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 02/16/2018] [Indexed: 12/24/2022] Open
Abstract
Ischemic stroke is a leading cause of morbidity and mortality in the US; however, there currently exists only one effective acute pharmacological therapeutic intervention. Purinergic signaling has been shown to regulate vascular function and pathological processes, including inflammation and arterial myogenic reactivity, and plays a role in ischemic stroke outcome. Purinergic signaling requires extracellular purines; however, the mechanism of purine release from cells is unclear. Pannexin1 (Panx1) channels are potentially novel purine release channels expressed throughout the vascular tree that couples regulated purine release with purinergic signaling. Therefore, we examined the role of smooth muscle and endothelial cell Panx1, using conditional cell type-specific transgenic mice, in cerebral ischemia/reperfusion injury outcomes. Deletion of endothelial cell Panx1, but not smooth muscle cell Panx1, significantly reduced cerebral infarct volume after ischemia/reperfusion. Infiltration of leukocytes into brain tissue and development of cerebral myogenic tone were both significantly reduced when mice lacked endothelial Panx1. Panx1 regulation of myogenic tone was unique to the cerebral circulation, as mesenteric myogenic reactivity and blood pressure were independent of endothelial Panx1. Overall, deletion of endothelial Panx1 mitigated cerebral ischemic injury by reducing inflammation and myogenic tone development, indicating that endothelial Panx1 is a possible novel target for therapeutic intervention of ischemic stroke.
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Affiliation(s)
- Miranda E Good
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Stephanie A. Eucker
- Division of Emergency Medicine, Department of Surgery, Duke University, Durham, North Carolina, USA
| | - Jun Li
- Department of Anesthesiology and
| | - Hannah M. Bacon
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Susan M. Lang
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Joshua T. Butcher
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Tyler J. Johnson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | | | | | | | - Brant E. Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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9
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Shestopalov VI, Panchin Y, Tarasova OS, Gaynullina D, Kovalzon VM. Pannexins Are Potential New Players in the Regulation of Cerebral Homeostasis during Sleep-Wake Cycle. Front Cell Neurosci 2017; 11:210. [PMID: 28769767 PMCID: PMC5511838 DOI: 10.3389/fncel.2017.00210] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/03/2017] [Indexed: 12/18/2022] Open
Abstract
During brain homeostasis, both neurons and astroglia release ATP that is rapidly converted to adenosine in the extracellular space. Pannexin-1 (Panx1) hemichannels represent a major conduit of non-vesicular ATP release from brain cells. Previous studies have shown that Panx1−/− mice possess severe disruption of the sleep-wake cycle. Here, we review experimental data supporting the involvement of pannexins (Panx) in the coordination of fundamental sleep-associated brain processes, such as neuronal activity and regulation of cerebrovascular tone. Panx1 hemichannels are likely implicated in the regulation of the sleep-wake cycle via an indirect effect of released ATP on adenosine receptors and through interaction with other somnogens, such as IL-1β, TNFα and prostaglandin D2. In addition to the recently established role of Panx1 in the regulation of endothelium-dependent arterial dilation, similar signaling pathways are the major cellular component of neurovascular coupling. The new discovered role of Panx in sleep regulation may have broad implications in coordinating neuronal activity and homeostatic housekeeping processes during the sleep-wake cycle.
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Affiliation(s)
- Valery I Shestopalov
- Institute for Information Transmission Problems, Russian Academy of SciencesMoscow, Russia.,Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of MedicineMiami, FL, United States.,Microbiology and Bioengineering Laboratory, Department of Genomics and Biotechnology, Vavilov Institute of General Genetics, Russian Academy of SciencesMoscow, Russia
| | - Yuri Panchin
- Institute for Information Transmission Problems, Russian Academy of SciencesMoscow, Russia.,Department of Mathematical Methods in Biology, Belozersky Institute, M.V. Lomonosov Moscow State UniversityMoscow, Russia
| | - Olga S Tarasova
- Institute for Information Transmission Problems, Russian Academy of SciencesMoscow, Russia.,Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State UniversityMoscow, Russia.,State Research Center of the Russian Federation, Institute for Biomedical Problems, Russian Academy of SciencesMoscow, Russia
| | - Dina Gaynullina
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State UniversityMoscow, Russia.,Department of Physiology, Russian National Research Medical UniversityMoscow, Russia
| | - Vladimir M Kovalzon
- Institute for Information Transmission Problems, Russian Academy of SciencesMoscow, Russia.,Severtsov Institute Ecology and Evolution, Russian Academy of SciencesMoscow, Russia
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10
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Begandt D, Good ME, Keller AS, DeLalio LJ, Rowley C, Isakson BE, Figueroa XF. Pannexin channel and connexin hemichannel expression in vascular function and inflammation. BMC Cell Biol 2017; 18:2. [PMID: 28124621 PMCID: PMC5267334 DOI: 10.1186/s12860-016-0119-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Control of blood flow distribution and tissue homeostasis depend on the tight regulation of and coordination between the microvascular network and circulating blood cells. Channels formed by connexins or pannexins that connect the intra- and extracellular compartments allow the release of paracrine signals, such as ATP and prostaglandins, and thus play a central role in achieving fine regulation and coordination of vascular function. This review focuses on vascular connexin hemichannels and pannexin channels. We review their expression pattern within the arterial and venous system with a special emphasis on how post-translational modifications by phosphorylation and S-nitrosylation of these channels modulate their function and contribute to vascular homeostasis. Furthermore, we highlight the contribution of these channels in smooth muscle cells and endothelial cells in the regulation of vasomotor tone as well as how these channels in endothelial cells regulate inflammatory responses such as during ischemic and hypoxic conditions. In addition, this review will touch on recent evidence implicating a role for these proteins in regulating red blood cell and platelet function.
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Affiliation(s)
- Daniela Begandt
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Miranda E Good
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Alex S Keller
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Leon J DeLalio
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Carol Rowley
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Brant E Isakson
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.,Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Xavier F Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
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11
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Abstract
Pannexin channels are newly discovered ATP release channels expressed throughout the body. Pannexin 1 (Panx1) channels have become of great interest as they appear to participate in a multitude of signalling cascades, including regulation of vascular function. Although numerous Panx1 pharmacological inhibitors have been discovered, these inhibitors are not specific for Panx1 and have additional effects on other proteins. Therefore, molecular tools, such as RNA interference and knockout animals, are needed to demonstrate the role of pannexins in various cellular functions. This review focuses on the known roles of Panx1 related to purinergic signalling in the vasculature focusing on post-translational modifications and channel gating mechanisms that may participate in the regulated release of ATP.
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12
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Decrock E, De Bock M, Wang N, Bultynck G, Giaume C, Naus CC, Green CR, Leybaert L. Connexin and pannexin signaling pathways, an architectural blueprint for CNS physiology and pathology? Cell Mol Life Sci 2015; 72:2823-51. [PMID: 26118660 PMCID: PMC11113968 DOI: 10.1007/s00018-015-1962-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/11/2015] [Indexed: 02/06/2023]
Abstract
The central nervous system (CNS) is composed of a highly heterogeneous population of cells. Dynamic interactions between different compartments (neuronal, glial, and vascular systems) drive CNS function and allow to integrate and process information as well as to respond accordingly. Communication within this functional unit, coined the neuro-glio-vascular unit (NGVU), typically relies on two main mechanisms: direct cell-cell coupling via gap junction channels (GJCs) and paracrine communication via the extracellular compartment, two routes to which channels composed of transmembrane connexin (Cx) or pannexin (Panx) proteins can contribute. Multiple isoforms of both protein families are present in the CNS and each CNS cell type is characterized by a unique Cx/Panx portfolio. Over the last two decades, research has uncovered a multilevel platform via which Cxs and Panxs can influence different cellular functions within a tissue: (1) Cx GJCs enable a direct cell-cell communication of small molecules, (2) Cx hemichannels and Panx channels can contribute to autocrine/paracrine signaling pathways, and (3) different structural domains of these proteins allow for channel-independent functions, such as cell-cell adhesion, interactions with the cytoskeleton, and the activation of intracellular signaling pathways. In this paper, we discuss current knowledge on their multifaceted contribution to brain development and to specific processes in the NGVU, including synaptic transmission and plasticity, glial signaling, vasomotor control, and blood-brain barrier integrity in the mature CNS. By highlighting both physiological and pathological conditions, it becomes evident that Cxs and Panxs can play a dual role in the CNS and that an accurate fine-tuning of each signaling mechanism is crucial for normal CNS physiology.
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Affiliation(s)
- Elke Decrock
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
| | - Marijke De Bock
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
| | - Nan Wang
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, KU Leuven, Louvain, Belgium
| | - Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, 75231 Paris Cedex 05, France
- University Pierre et Marie
Curie, ED, N°158, 75005 Paris, France
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005 Paris, France
| | - Christian C. Naus
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3 Canada
| | - Colin R. Green
- Department of Ophthalmology, The University of Auckland, Auckland, New Zealand
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
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13
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Meens MJ, Kwak BR, Duffy HS. Role of connexins and pannexins in cardiovascular physiology. Cell Mol Life Sci 2015; 72:2779-92. [PMID: 26091747 PMCID: PMC11113959 DOI: 10.1007/s00018-015-1959-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/11/2015] [Indexed: 12/26/2022]
Abstract
Connexins and pannexins form connexons, pannexons and membrane channels, which are critically involved in many aspects of cardiovascular physiology. For that reason, a vast number of studies have addressed the role of connexins and pannexins in the arterial and venous systems as well as in the heart. Moreover, a role for connexins in lymphatics has recently also been suggested. This review provides an overview of the current knowledge regarding the involvement of connexins and pannexins in cardiovascular physiology.
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Affiliation(s)
- Merlijn J. Meens
- Department of Pathology and Immunology, University of Geneva, Rue Michel-Servet 1, 1211 Geneva 4, Switzerland
- Department of Medical Specializations-Cardiology, University of Geneva, Geneva, Switzerland
| | - Brenda R. Kwak
- Department of Pathology and Immunology, University of Geneva, Rue Michel-Servet 1, 1211 Geneva 4, Switzerland
- Department of Medical Specializations-Cardiology, University of Geneva, Geneva, Switzerland
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14
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Diezmos EF, Sandow SL, Perera DS, King DW, Bertrand PP, Liu L. Pannexin-2 is expressed in the human colon with extensive localization in the enteric nervous system. Neurogastroenterol Motil 2015; 27:672-83. [PMID: 25773474 DOI: 10.1111/nmo.12541] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 02/16/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND Pannexin-2 (Panx2) is a member of the novel group of membrane spanning protein channels present in the central nervous system. Limited studies have examined Panx2 in the intestine, where it may have important physiological roles. The present study characterized Panx2 expression and localization in the human colon in health and disease states. METHODS Immunofluorescence determined Panx2 localization and co-localization, and quantitative real-time PCR and Western blot determined gene and protein expression in ulcerative colitis (UC), Crohn's disease (CD), and control human colon. KEY RESULTS Panx2 was widely expressed in myenteric and submucosal ganglia, particularly in the cytoplasm of neurons. Panx2 was also expressed on smooth muscle of the muscularis and blood vessels, some non-lymphoid leukocytes, mast cells, and mucosal epithelial cells. Co-localization of Panx2 occurred with β-tubulin, neuronal nitric oxide synthase, substance P, vesicular acetylcholine transporter, and calcitonin gene-related peptide, indicating widespread Panx2 expression in extrinsic and intrinsic neurons. Molecular studies revealed a 3.4-fold higher level of Panx2 mRNA in ascending compared to sigmoid muscularis (p < 0.05), despite similar protein levels. Similarly, UC muscularis showed a 35-fold up-regulation in Panx2 mRNA, but not in protein (p < 0.05). CONCLUSIONS & INFERENCES Here, we demonstrated the dense expression of Panx2 in the enteric nervous system and the co-localization of Panx2 with a spectrum of neuronal markers, indicating that Panx2 may be involved in mediating neurotransmission in the colon. The substantial increase in Panx2 mRNA in UC muscle but not protein suggests that the Panx2 translation process may be disrupted in UC.
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Affiliation(s)
- E F Diezmos
- School of Medical Sciences, UNSW Australia, Sydney, NSW, Australia
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15
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Freitas-Andrade M, Naus CC. Astrocytes in neuroprotection and neurodegeneration: The role of connexin43 and pannexin1. Neuroscience 2015; 323:207-21. [PMID: 25913636 DOI: 10.1016/j.neuroscience.2015.04.035] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 04/13/2015] [Accepted: 04/15/2015] [Indexed: 12/26/2022]
Abstract
The World Health Organization has predicted that by 2040 neurodegenerative diseases will overtake cancer to become the world's second leading cause of death after cardiovascular disease. This has sparked the development of several European and American brain research initiatives focusing on elucidating the underlying cellular and molecular mechanisms of neurodegenerative diseases. Connexin (Cx) and pannexin (Panx) membrane channel proteins are conduits through which neuronal, glial, and vascular tissues interact. In the brain, this interaction is highly critical for homeostasis and brain repair after injury. Understanding the molecular mechanisms by which these membrane channels function, in health and disease, might be particularly influential in establishing conceptual frameworks to develop new therapeutics against Cx and Panx channels. This review focuses on current insights and emerging concepts, particularly the impact of connexin43 and pannexin1, under neuroprotective and neurodegenerative conditions within the context of astrocytes.
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Affiliation(s)
- M Freitas-Andrade
- Department of Cellular and Physiological Sciences, The Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - C C Naus
- Department of Cellular and Physiological Sciences, The Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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16
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Boassa D, Nguyen P, Hu J, Ellisman MH, Sosinsky GE. Pannexin2 oligomers localize in the membranes of endosomal vesicles in mammalian cells while Pannexin1 channels traffic to the plasma membrane. Front Cell Neurosci 2015; 8:468. [PMID: 25698922 PMCID: PMC4313697 DOI: 10.3389/fncel.2014.00468] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 12/27/2014] [Indexed: 12/13/2022] Open
Abstract
Pannexin2 (Panx2) is the largest of three members of the pannexin proteins. Pannexins are topologically related to connexins and innexins, but serve different functional roles than forming gap junctions. We previously showed that pannexins form oligomeric channels but unlike connexins and innexins, they form only single membrane channels. High levels of Panx2 mRNA and protein in the Central Nervous System (CNS) have been documented. Whereas Pannexin1 (Panx1) is fairly ubiquitous and Pannexin3 (Panx3) is found in skin and connective tissue, both are fully glycosylated, traffic to the plasma membrane and have functions correlated with extracellular ATP release. Here, we describe trafficking and subcellular localizations of exogenous Panx2 and Panx1 protein expression in MDCK, HeLa, and HEK 293T cells as well as endogenous Panx1 and Panx2 patterns in the CNS. Panx2 was found in intracellular localizations, was partially N-glycosylated, and localizations were non-overlapping with Panx1. Confocal images of hippocampal sections immunolabeled for the astrocytic protein GFAP, Panx1 and Panx2 demonstrated that the two isoforms, Panx1 and Panx2, localized at different subcellular compartments in both astrocytes and neurons. Using recombinant fusions of Panx2 with appended genetic tags developed for correlated light and electron microscopy and then expressed in different cell lines, we determined that Panx2 is localized in the membrane of intracellular vesicles and not in the endoplasmic reticulum as initially indicated by calnexin colocalization experiments. Dual immunofluorescence imaging with protein markers for specific vesicle compartments showed that Panx2 vesicles are early endosomal in origin. In electron tomographic volumes, cross-sections of these vesicles displayed fine structural details and close proximity to actin filaments. Thus, pannexins expressed at different subcellular compartments likely exert distinct functional roles, particularly in the nervous system.
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Affiliation(s)
- Daniela Boassa
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA
| | - Phuong Nguyen
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA
| | - Junru Hu
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA ; Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Gina E Sosinsky
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, La Jolla, CA, USA ; Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
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17
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Functional Role of Connexins and Pannexins in the Interaction Between Vascular and Nervous System. J Cell Physiol 2014; 229:1336-45. [DOI: 10.1002/jcp.24563] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 01/16/2014] [Indexed: 01/22/2023]
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18
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Abstract
The pannexins (Panxs) are a family of chordate proteins homologous to the invertebrate gap junction forming proteins named innexins. Three distinct Panx paralogs (Panx1, Panx2, and Panx3) are shared among the major vertebrate phyla, but they appear to have suppressed (or even lost) their ability to directly couple adjacent cells. Connecting the intracellular and extracellular compartments is now widely accepted as Panx's primary function, facilitating the passive movement of ions and small molecules along electrochemical gradients. The tissue distribution of the Panxs ranges from pervasive to very restricted, depending on the paralog, and are often cell type-specific and/or developmentally regulated within any given tissue. In recent years, Panxs have been implicated in an assortment of physiological and pathophysiological processes, particularly with respect to ATP signaling and inflammation, and they are now considered to be a major player in extracellular purinergic communication. The following is a comprehensive review of the Panx literature, exploring the historical events leading up to their discovery, outlining our current understanding of their biochemistry, and describing the importance of these proteins in health and disease.
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Affiliation(s)
- Stephen R Bond
- Genome Technology Branch, Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health Bethesda, MD, USA ; Department of Cellular and Physiological Science, Life Sciences Institute, University of British Columbia Vancouver, BC, Canada
| | - Christian C Naus
- Department of Cellular and Physiological Science, Life Sciences Institute, University of British Columbia Vancouver, BC, Canada
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19
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Rosell A. Pannexins after stroke. Channels (Austin) 2013; 7:58-9. [PMID: 23665614 PMCID: PMC3667884 DOI: 10.4161/chan.24143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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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] [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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21
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Simard JM, Woo SK, Schwartzbauer GT, Gerzanich V. Sulfonylurea receptor 1 in central nervous system injury: a focused review. J Cereb Blood Flow Metab 2012; 32:1699-717. [PMID: 22714048 PMCID: PMC3434627 DOI: 10.1038/jcbfm.2012.91] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 05/03/2012] [Accepted: 05/09/2012] [Indexed: 01/13/2023]
Abstract
The sulfonylurea receptor 1 (Sur1)-regulated NC(Ca-ATP) channel is a nonselective cation channel that is regulated by intracellular calcium and adenosine triphosphate. The channel is not constitutively expressed, but is transcriptionally upregulated de novo in all cells of the neurovascular unit, in many forms of central nervous system (CNS) injury, including cerebral ischemia, traumatic brain injury (TBI), spinal cord injury (SCI), and subarachnoid hemorrhage (SAH). The channel is linked to microvascular dysfunction that manifests as edema formation and delayed secondary hemorrhage. Also implicated in oncotic cell swelling and oncotic (necrotic) cell death, the channel is a major molecular mechanism of 'accidental necrotic cell death' in the CNS. In animal models of SCI, pharmacological inhibition of Sur1 by glibenclamide, as well as gene suppression of Abcc8, prevents delayed capillary fragmentation and tissue necrosis. In models of stroke and TBI, glibenclamide ameliorates edema, secondary hemorrhage, and tissue damage. In a model of SAH, glibenclamide attenuates the inflammatory response due to extravasated blood. Clinical trials of an intravenous formulation of glibenclamide in TBI and stroke underscore the importance of recent advances in understanding the role of the Sur1-regulated NC(Ca-ATP) channel in acute ischemic, traumatic, and inflammatory injury to the CNS.
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Affiliation(s)
- J Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland 21201-1595, USA.
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