101
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Freitas-Andrade M, Wang N, Bechberger JF, De Bock M, Lampe PD, Leybaert L, Naus CC. Targeting MAPK phosphorylation of Connexin43 provides neuroprotection in stroke. J Exp Med 2019; 216:916-935. [PMID: 30872361 PMCID: PMC6446879 DOI: 10.1084/jem.20171452] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 03/31/2018] [Accepted: 02/08/2019] [Indexed: 12/13/2022] Open
Abstract
This study demonstrates that astrocytic connexin43 gap junction hemichannels are largely controlled by four C-terminal tail–located serine residues and provides mechanistic insight on how phosphorylation of these residues affects recovery from stroke. Connexin43 (Cx43) function is influenced by kinases that phosphorylate specific serine sites located near its C-terminus. Stroke is a powerful inducer of kinase activity, but its effect on Cx43 is unknown. We investigated the impact of wild-type (WT) and knock-in Cx43 with serine to alanine mutations at the protein kinase C (PKC) site Cx43S368A, the casein kinase 1 (CK1) sites Cx43S325A/328Y/330A, and the mitogen-activated protein kinase (MAPK) sites Cx43S255/262/279/282A (MK4) on a permanent middle cerebral artery occlusion (pMCAO) stroke model. We demonstrate that MK4 transgenic animals exhibit a significant decrease in infarct volume that was associated with improvement in behavioral performance. An increase in astrocyte reactivity with a concomitant decrease in microglial reactivity was observed in MK4 mice. In contrast to WT, MK4 astrocytes displayed reduced Cx43 hemichannel activity. Pharmacological blockade of Cx43 hemichannels with TAT-Gap19 also significantly decreased infarct volume in WT animals. This study provides novel molecular insights and charts new avenues for therapeutic intervention associated with Cx43 function.
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Affiliation(s)
- Moises Freitas-Andrade
- Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nan Wang
- Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - John F Bechberger
- Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Marijke De Bock
- Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Paul D Lampe
- Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Luc Leybaert
- Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Christian C Naus
- Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
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102
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Giaume C, Sáez JC, Song W, Leybaert L, Naus CC. Connexins and pannexins in Alzheimer’s disease. Neurosci Lett 2019; 695:100-105. [DOI: 10.1016/j.neulet.2017.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 08/14/2017] [Accepted: 09/01/2017] [Indexed: 12/22/2022]
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103
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Sciuto KJ, Deng SW, Moreno A, Zaitsev AV. Chronology of critical events in neonatal rat ventricular myocytes occurring during reperfusion after simulated ischemia. PLoS One 2019; 14:e0212076. [PMID: 30730997 PMCID: PMC6366697 DOI: 10.1371/journal.pone.0212076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 01/25/2019] [Indexed: 11/19/2022] Open
Abstract
While an ischemic insult poses a lethal danger to myocardial cells, a significant proportion of cardiac myocytes remain viable throughout the ischemic episode and die, paradoxically, only after the blood flow is reinstated. Despite decades of research, the actual chronology of critical events leading to cardiomyocyte death during the reperfusion phase remains poorly understood. Arguably, identification of the pivotal event in this setting is necessary to design effective strategies aimed at salvaging the myocardium after an ischemic attack. Here we used neonatal rat ventricular myocytes (NRVMs) subjected to 20–30 min of simulated ischemia followed by 1 hour of “reperfusion”. Using different combinations of spectrally-compatible fluorescent indicators, we analyzed the relative timing of the following events: (1) abnormal increase in cytoplasmic [Ca2+] (TCaCy); (2) abnormal increase in mitochondrial [Ca2+] (TCaMi); (3) loss of mitochondrial inner membrane potential (ΔΨm) indicating mitochondrial permeability transitions (TMPT); (4) sacrolemmal permeabilization (SP) to the normally impermeable small fluorophore TO-PRO3 (TSP). In additional experiments we also analyzed the timing of abnormal uptake of Zn2+ into the cytoplasm (TZnCy) relative to TCaCy and TSP. We focused on those NRVMs which survived anoxia, as evidenced by at least 50% recovery of ΔΨm and the absence of detectable SP. In these cells, we found a consistent sequence of critical events in the order, from first to last, of TCaCy, TCaMi, TMPT, TSP. After detecting TCaCy and TCaMi, abrupt switches between 1.1 mM and nominally zero [Ca2+] in the perfusate quickly propagated to the cytoplasmic and mitochondrial [Ca2+]. Depletion of the sarcoplasmic reticulum with ryanodine (5 μM)/thapsigargin (1 μM) accelerated all events without changing their order. In the presence of ZnCl2 (10–30 μM) in the perfusate we found a consistent timing sequence TCaCy < TZn ≤ TSP. In some cells ZnCl2 interfered with Ca2+ uptake, causing “steps” or “gaps” in the [Ca2+]Cy curve, a phenomenon never observed in the absence of ZnCl2. Together, these findings suggest an evolving permeabilization of NRVM’s sarcolemma during reoxygenation, in which the expansion of the pore size determines the timing of critical events, including TMPT.
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Affiliation(s)
- Katie J. Sciuto
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States of America
| | - Steven W. Deng
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States of America
| | - Alonso Moreno
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Department of Internal Medicine, School of Medicine, University of Utah, Salt Lake City, Utah, United States of America
| | - Alexey V. Zaitsev
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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104
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George SA, Hoeker G, Calhoun PJ, Entz M, Raisch TB, King DR, Khan M, Baker C, Gourdie RG, Smyth JW, Nielsen MS, Poelzing S. Modulating cardiac conduction during metabolic ischemia with perfusate sodium and calcium in guinea pig hearts. Am J Physiol Heart Circ Physiol 2019; 316:H849-H861. [PMID: 30707595 DOI: 10.1152/ajpheart.00083.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We previously demonstrated that altering extracellular sodium (Nao) and calcium (Cao) can modulate a form of electrical communication between cardiomyocytes termed "ephaptic coupling" (EpC), especially during loss of gap junction coupling. We hypothesized that altering Nao and Cao modulates conduction velocity (CV) and arrhythmic burden during ischemia. Electrophysiology was quantified by optically mapping Langendorff-perfused guinea pig ventricles with modified Nao (147 or 155 mM) and Cao (1.25 or 2.0 mM) during 30 min of simulated metabolic ischemia (pH 6.5, anoxia, aglycemia). Gap junction-adjacent perinexal width ( WP), a candidate cardiac ephapse, and connexin (Cx)43 protein expression and Cx43 phosphorylation at S368 were quantified by transmission electron microscopy and Western immunoblot analysis, respectively. Metabolic ischemia slowed CV in hearts perfused with 147 mM Nao and 2.0 mM Cao; however, theoretically increasing EpC with 155 mM Nao was arrhythmogenic, and CV could not be measured. Reducing Cao to 1.25 mM expanded WP, as expected during ischemia, consistent with reduced EpC, but attenuated CV slowing while delaying arrhythmia onset. These results were further supported by osmotically reducing WP with albumin, which exacerbated CV slowing and increased early arrhythmias during ischemia, whereas mannitol expanded WP, permitted conduction, and delayed the onset of arrhythmias. Cx43 expression patterns during the various interventions insufficiently correlated with observed CV changes and arrhythmic burden. In conclusion, decreasing perfusate calcium during metabolic ischemia enhances perinexal expansion, attenuates conduction slowing, and delays arrhythmias. Thus, perinexal expansion may be cardioprotective during metabolic ischemia. NEW & NOTEWORTHY This study demonstrates, for the first time, that modulating perfusate ion composition can alter cardiac electrophysiology during simulated metabolic ischemia.
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Affiliation(s)
- Sharon A George
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University , Blacksburg, Virginia.,Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia
| | - Gregory Hoeker
- Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia
| | - Patrick J Calhoun
- Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia.,Department of Biological Sciences, Virginia Polytechnic Institute and State University , Blacksburg, Virginia
| | - Michael Entz
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University , Blacksburg, Virginia.,Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia
| | - Tristan B Raisch
- Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia.,Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University , Blacksburg, Virginia
| | - D Ryan King
- Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia.,Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University , Blacksburg, Virginia
| | - Momina Khan
- Department of Human Food Nutrition and Exercise, Virginia Polytechnic Institute and State University , Blacksburg, Virginia
| | - Chandra Baker
- Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia
| | - Robert G Gourdie
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University , Blacksburg, Virginia.,Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia
| | - James W Smyth
- Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia.,Department of Biological Sciences, Virginia Polytechnic Institute and State University , Blacksburg, Virginia
| | - Morten S Nielsen
- Department of Biomedical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Steven Poelzing
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University , Blacksburg, Virginia.,Center for Heart and Reparative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia.,Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University , Blacksburg, Virginia
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105
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Wu F, Gao A, Liu J, Shen Y, Xu P, Meng J, Wen T, Xu L, Xu H. High Modulus Conductive Hydrogels Enhance In Vitro Maturation and Contractile Function of Primary Cardiomyocytes for Uses in Drug Screening. Adv Healthc Mater 2018; 7:e1800990. [PMID: 30565899 DOI: 10.1002/adhm.201800990] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/13/2018] [Indexed: 12/20/2022]
Abstract
Effective and quick screening and cardiotoxicity assessment are very crucial for drug development. Here, a novel composite hydrogel composed of carbon fibers (CFs) with high conductivity and modulus with polyvinyl alcohol (PVA) is reported. The conductivity of the composite hydrogel PVA/CFs is similar to that of natural heart tissue, and the elastic modulus is close to that of natural heart tissue during systole, due to the incorporation of CFs. PVA/CFs remarkably enhance the maturation of neonatal rat cardiomyocytes (NRCM) in vitro by upregulating the expression of α-actinin, troponin T, and connexin-43, activating the signaling pathway of α5 and β1 integrin-dependent ILK/p-AKT, and increasing the level of RhoA and hypoxia-inducible factor-1α. As a result, the engineered cell sheet-like constructs NRCM@PVA/CFs display much more synchronous, stable, and robust beating behavior than NRCM@PVA. When exposed to doxorubicin or isoprenaline, NRCM@PVA/CFs can retain effective beating for much longer time or change the contractile rate much faster than NRCM@PVA, respectively, therefore representing a promising heart-like platform for in vitro drug screening and cardiotoxicity assessment.
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Affiliation(s)
- Fengxin Wu
- Institute of Basic Medical Sciences; Chinese Academy of Medical Sciences & Peking Union Medical College; Beijing 100010 China
| | - Aijun Gao
- National Carbon Fiber Engineering Technology Center; Beijing University of Chemical Technology; Beijing 100029 China
| | - Jian Liu
- Institute of Basic Medical Sciences; Chinese Academy of Medical Sciences & Peking Union Medical College; Beijing 100010 China
| | - Yaoyi Shen
- Institute of Basic Medical Sciences; Chinese Academy of Medical Sciences & Peking Union Medical College; Beijing 100010 China
| | - Panpan Xu
- National Carbon Fiber Engineering Technology Center; Beijing University of Chemical Technology; Beijing 100029 China
| | - Jie Meng
- Institute of Basic Medical Sciences; Chinese Academy of Medical Sciences & Peking Union Medical College; Beijing 100010 China
| | - Tao Wen
- Institute of Basic Medical Sciences; Chinese Academy of Medical Sciences & Peking Union Medical College; Beijing 100010 China
| | - Lianghua Xu
- National Carbon Fiber Engineering Technology Center; Beijing University of Chemical Technology; Beijing 100029 China
| | - Haiyan Xu
- Institute of Basic Medical Sciences; Chinese Academy of Medical Sciences & Peking Union Medical College; Beijing 100010 China
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106
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Wang Q, Zhou C, Li X, Cai L, Zou J, Zhang D, Xie J, Lai W. TGF-β1 promotes gap junctions formation in chondrocytes via Smad3/Smad4 signalling. Cell Prolif 2018; 52:e12544. [PMID: 30444057 PMCID: PMC6495951 DOI: 10.1111/cpr.12544] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/04/2018] [Accepted: 09/21/2018] [Indexed: 02/05/2023] Open
Abstract
Objectives Connexin‐mediated functional gap junction intercellular communication (GJIC) has a vital role in development, homeostasis and pathology. Transforming growth factor‐β1 (TGF‐β1), as one of the most vital factors in chondrocytes, promotes cartilage precursor cell differentiation and chondrocyte proliferation, migration and metabolism. However, how TGF‐β1 mediates GJIC in chondrocytes remains unclear. This study aims to determine the influence of TGF‐β1 on GJIC in mouse chondrocytes and its underlying mechanism. Methods qPCR and mRNA microarray were used to verify the expression of genes in the TGF‐β and connexin families in cartilage and chondrocytes. A scrape loading/dye transfer assay was performed to explore GJIC. Western blot analysis was used to detect connexin43 (Cx43) and Smad signalling components. Immunofluorescence staining was performed to characterize protein distribution. Results The TGF‐β1 mRNA was the highest expressed member of the TGFβ super family in cartilage. TGF‐β1 promoted functional GJIC through increased expression of Cx43. TGF‐β1‐mediated GJIC required the participation of TGF‐β type I receptor. TGF‐β1 activated Smad3 and Smad4 signalling to facilitate their nuclear translocation. The Smad3 and Smad4 signalling proteins bound to the promoter of Gja1 and thus initiated Cx43 gene expression. Conclusions For the first time, these results revealed a vital role of TGF‐β1 in cell‐cell communication in chondrocytes via gap junction formation. We describe the regulatory mechanism, the involvement of TGF‐β type I receptor and the nuclear translocation of Smad3/4.
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Affiliation(s)
- Qingxuan Wang
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Chenchen Zhou
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xiaobing Li
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Linyi Cai
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Zou
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Demao Zhang
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Wenli Lai
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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107
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Chen Y, Wang L, Zhang L, Chen B, Yang L, Li X, Li Y, Yu H. Inhibition of Connexin 43 Hemichannels Alleviates Cerebral Ischemia/Reperfusion Injury via the TLR4 Signaling Pathway. Front Cell Neurosci 2018; 12:372. [PMID: 30386214 PMCID: PMC6199357 DOI: 10.3389/fncel.2018.00372] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 09/28/2018] [Indexed: 01/01/2023] Open
Abstract
Connexin 43 (Cx43) widely exists in all components of the neurovascular unit (NVU) and is a constituent of gap junctions and hemichannels. In physiological states, gap junctions are open for regular intercellular communication, and the hemichannels present low open probability in astrocytes. After cerebral ischemia, a large number of hemichannels are unusually opened, leading to cell swelling and even death. Most known hemichannel blockers also inhibit gap junctions and sequentially obstruct normal electrical cell-cell communication. In this study, we tested the hypothesis that Gap19, a selective Cx43-hemichannel inhibitor, exhibited neuroprotective effects on cerebral ischemia/reperfusion (I/R). An obvious improvement in neurological scores and infarct volume reduction were observed in Gap19-treated mice after brain ischemia induced by middle cerebral artery occlusion (MCAO). Gap19 treatment attenuated white matter damage. Moreover, Gap19 treatment suppressed the expression of Cx43 and Toll-like receptor 4 (TLR4) pathway-relevant proteins and prevented the overexpression of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). To further explore downstream signaling, we established an in vitro model-oxygen glucose deprivation (OGD) to simulate ischemic conditions. Immunofluorescence staining showed that Cx43 co-existed with TLR4 in astrocytes. The hemichannel activity was increased after OGD and Gap19 could inhibit this effect on astrocytes. Gap19 substantially improved relative cell vitality and decreased the expression of Cx43, TLR4 and inflammatory cytokines in vitro. In addition, in the lipopolysaccharide (LPS) stimulation OGD model, Gap19 also exhibited a protective effect via inhibiting TLR4 pathway activation. In summary, our results showed that Gap19 exerted a neuroprotective effect after stroke via inhibition of the TLR4-mediated signaling pathway.
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Affiliation(s)
- Yingzhu Chen
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Liangzhu Wang
- Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China.,Dalian Medical University, Dalian, China
| | - Lingling Zhang
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Beilei Chen
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Liu Yang
- Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China.,Dalian Medical University, Dalian, China
| | - Xiaobo Li
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China.,Institute of Neuroscience, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Yuping Li
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Hailong Yu
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China.,Institute of Neuroscience, Northern Jiangsu People's Hospital, Yangzhou, China.,Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China
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108
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Hamanaka G, Ohtomo R, Takase H, Lok J, Arai K. White-matter repair: Interaction between oligodendrocytes and the neurovascular unit. Brain Circ 2018; 4:118-123. [PMID: 30450418 PMCID: PMC6187946 DOI: 10.4103/bc.bc_15_18] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/06/2018] [Accepted: 09/10/2018] [Indexed: 02/06/2023] Open
Abstract
There are currently no adequate treatments for white-matter injury, which often follows central nervous system maladies and their accompanying neurodegenerative processes. Indeed, the white matter is compromised by the deterioration of the blood–brain barrier and the demyelination of neuronal axons. Key repairs to the white matter are mediated by oligodendrocyte lineage cells after damaging events. Oligodendrocytes are supported by other cells in the neurovascular unit and these cells collaborate in processes such as angiogenesis, neurogenesis, and oligodendrogenesis. Understanding the various interactions between these cells and oligodendrocytes will be imperative for developing reparative therapies for impaired white matter. This minireview will discuss how oligodendrocytes and oligodendrocyte lineage cells mend damage to the white matter and restore brain function ensuing neural injury.
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Affiliation(s)
- Gen Hamanaka
- Department of Radiology and Neurology, Neuroprotection Research Laboratory, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Ryo Ohtomo
- Department of Radiology and Neurology, Neuroprotection Research Laboratory, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Hajime Takase
- Department of Radiology and Neurology, Neuroprotection Research Laboratory, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Josephine Lok
- Department of Radiology and Neurology, Neuroprotection Research Laboratory, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Ken Arai
- Department of Radiology and Neurology, Neuroprotection Research Laboratory, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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109
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Li K, Zhou H, Zhan L, Shi Z, Sun W, Liu D, Liu L, Liang D, Tan Y, Xu W, Xu E. Hypoxic Preconditioning Maintains GLT-1 Against Transient Global Cerebral Ischemia Through Upregulating Cx43 and Inhibiting c-Src. Front Mol Neurosci 2018; 11:344. [PMID: 30323740 PMCID: PMC6172853 DOI: 10.3389/fnmol.2018.00344] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 09/03/2018] [Indexed: 01/06/2023] Open
Abstract
Transient global cerebral ischemia (tGCI) causes excessive release of glutamate from neurons. Astrocytic glutamate transporter-1 (GLT-1) and glutamine synthetase (GS) together play a predominant role in maintaining glutamate at normal extracellular concentrations. Though our previous studies reported the alleviation of tGCI-induced neuronal death by hypoxic preconditioning (HPC) in hippocampal Cornu Ammonis 1 (CA1) of adult rats, the underlying mechanism has not yet been fully elaborated. In this study, we aimed to investigate the roles of GLT-1 and GS in the neuroprotection mediated by HPC against tGCI and to ascertain whether these roles can be regulated by connexin 43 (Cx43) and cellular-Src (c-Src) activity. We found that HPC decreased the level of extracellular glutamate in CA1 after tGCI via maintenance of GLT-1 expression and GS activity. Inhibition of GLT-1 expression with dihydrokainate (DHK) or inhibition of GS activity with methionine sulfoximine (MSO) abolished the neuroprotection induced by HPC. Also, HPC markedly upregulated Cx43 and inhibited p-c-Src expression in CA1 after tGCI, whereas inhibition of Cx43 with Gap26 dramatically reversed this effect. Furthermore, inhibition of p-c-Src with 4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo (3, 4-d) pyrimidine (PP2) decreased c-Src activity, increased protein levels of GLT-1 and Cx43, enhanced GS activity, and thus reduced extracellular glutamate level in CA1 after tGCI. Collectively, our data demonstrated that reduced extracellular glutamate induced by HPC against tGCI through preventing the reduction of GLT-1 expression and maintaining GS activity in hippocampal CA1, which was mediated by upregulating Cx43 expression and inhibiting c-Src activity.
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Affiliation(s)
- Kongping Li
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Huarong Zhou
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Lixuan Zhan
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Zhe Shi
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Weiwen Sun
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Dandan Liu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Liu Liu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Donghai Liang
- Department of Environmental Health Sciences, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Yafu Tan
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.,Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Wensheng Xu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - En Xu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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110
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Hamanaka G, Ohtomo R, Takase H, Lok J, Arai K. Role of oligodendrocyte-neurovascular unit in white matter repair. Neurosci Lett 2018; 684:175-180. [DOI: 10.1016/j.neulet.2018.07.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 07/09/2018] [Indexed: 12/20/2022]
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111
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Arshad M, Conzelmann C, Riaz MA, Noll T, Gündüz D. Inhibition of Cx43 attenuates ERK1/2 activation, enhances the expression of Cav‑1 and suppresses cell proliferation. Int J Mol Med 2018; 42:2811-2818. [PMID: 30132504 DOI: 10.3892/ijmm.2018.3828] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 07/31/2018] [Indexed: 11/06/2022] Open
Abstract
In addition to being an important component of the gap junction, connexin 43 (Cx43) has been shown to regulate other cellular functions, including cell proliferation. This regulatory role of Cx43 may be important in therapeutic situations, including wound healing or ischemic injuries. Caveolin‑1 (Cav‑1) has been shown to regulate angiogenesis. The aim of the present study was to analyze whether Cx43 counter‑regulates Cav‑1 in controlling the proliferation and migration of endothelial cells. The inhibition of Cx43 with niflumic acid, flufenamic acid and 18‑α‑glycyrrhetinic acid in cultured human umbilical vein endothelial cells resulted in decreased phosphorylation of extracellular signal‑regulated kinase (ERK)1/2 and increased expression of Cav‑1, as shown by western blot analysis. Furthermore, the inhibition of Cx43 resulted in a 50±7% decrease in cell proliferation, determined using a crystal violet assay, a 48±5% decrease in migration, determined using a migration assay, and a 49±6% decrease in endothelial tube formation, determined using a Matrigel assay, compared with the control. Similar results were obtained following specific inhibition of Cx43 by mimetic peptides (Gap26 and Gap27). Inhibition of the mitogen‑activated protein kinase kinase/ERK pathway with PD‑98059 resulted in an increased expression of Cav‑1 and a reduction in the expression of Cx43. Furthermore, cell proliferation, migration and tube formation in endothelial cells were impaired. By contrast, downregulation of the protein expression of Cav‑1 by small interference RNA resulted in increased expression of Cx43 and phosphorylation of ERK1/2. Accordingly, the number of cells in the Cav‑1 treated‑group increased by 35±5% compared with the controls. The data of the present study showed that Cav‑1 suppressed cell proliferation by inhibiting the activity of Cx43, which is upstream of ERK1/2. The downregulation of Cav‑1 protein resulted in loss of the inhibitory activity of Cav‑1 on cell proliferation and led to increased cell proliferation. This counter‑regulatory effect of Cx43 may be of importance in therapeutic angiogenesis.
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Affiliation(s)
- Muhammad Arshad
- Department of Cardiology and Angiology, University Hospital Giessen and Marburg, D‑35392 Giessen, Germany
| | - Charlotte Conzelmann
- Department of Cardiology and Angiology, University Hospital Giessen and Marburg, D‑35392 Giessen, Germany
| | - Muhammad Assad Riaz
- Department of Radiotherapy, University Hospital Essen, D‑45147 Essen, Germany
| | - Thomas Noll
- Institute of Physiology, Carl Gustav Carus Technical University of Dresden, D‑01307 Dresden, Germany
| | - Dursun Gündüz
- Department of Cardiology and Angiology, University Hospital Giessen and Marburg, D‑35392 Giessen, Germany
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112
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Rosenberg JH, Werner JH, Moulton MJ, Agrawal DK. Current Modalities and Mechanisms Underlying Cardioprotection by Ischemic Conditioning. J Cardiovasc Transl Res 2018; 11:292-307. [PMID: 29797232 PMCID: PMC6117210 DOI: 10.1007/s12265-018-9813-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/14/2018] [Indexed: 02/07/2023]
Abstract
Ischemic preconditioning is a process which serves to mitigate reperfusion injury. Preconditioning of the heart can be achieved through natural, pharmacological, and mechanical means. Mechanical preconditioning appears to have the greatest chance of good outcomes while methods employing pharmacologic preconditioning have been largely unsuccessful. Remote ischemic preconditioning achieves a cardioprotective effect by applying cycles of ischemia and reperfusion in a distal limb, stimulating the release of a neurohumoral cardioprotective factor incited by stimulation of afferent neurons. The cardioprotective factor stimulates the reperfusion injury salvage kinase (RISK) and survivor activator factor enhancement (SAFE) signaling cascades in cardiomyocytes which promote cell survival by the expression of anti-apoptotic genes and inhibition of the opening of mitochondrial permeability transition pores. Clinical application of ischemic preconditioning involving targets in the RISK and SAFE signaling appears promising in the treatment of acute myocardial infarction; however, clinical trials have yet to demonstrate additional benefit to current therapy.
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Affiliation(s)
- John H Rosenberg
- Department of Clinical & Translational Science, The Peekie Nash Carpenter Endowed Chair in Medicine, Creighton University School of Medicine, CRISS II Room 510, 2500 California Plaza, Omaha, NE, 68178, USA
| | - John H Werner
- Department of Clinical & Translational Science, The Peekie Nash Carpenter Endowed Chair in Medicine, Creighton University School of Medicine, CRISS II Room 510, 2500 California Plaza, Omaha, NE, 68178, USA
| | - Michael J Moulton
- Department of Cardiothoracic Surgery, University of Nebraska Medical Center, Omaha, NE, USA
| | - Devendra K Agrawal
- Department of Clinical & Translational Science, The Peekie Nash Carpenter Endowed Chair in Medicine, Creighton University School of Medicine, CRISS II Room 510, 2500 California Plaza, Omaha, NE, 68178, USA.
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113
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Basheer WA, Shaw RM. Connexin 43 and CaV1.2 Ion Channel Trafficking in Healthy and Diseased Myocardium. Circ Arrhythm Electrophysiol 2018; 9:e001357. [PMID: 27266274 DOI: 10.1161/circep.115.001357] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 04/29/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Wassim A Basheer
- From the Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA (W.A.B., R.M.S.); and Department of Medicine, University of California Los Angeles (R.M.S.)
| | - Robin M Shaw
- From the Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA (W.A.B., R.M.S.); and Department of Medicine, University of California Los Angeles (R.M.S.).
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114
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Jovanović A. Cardioprotective signalling: Past, present and future. Eur J Pharmacol 2018; 833:314-319. [PMID: 29935170 DOI: 10.1016/j.ejphar.2018.06.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/08/2018] [Accepted: 06/19/2018] [Indexed: 11/29/2022]
Abstract
A few decades ago, cardiac muscle was discovered to possess signalling pathways that, when activated, protect the myocardium against the damage induced by ischaemia-reperfusion. The ability of cardiac muscle to protect itself against injury has been termed 'cardioprotection'. Many compounds and procedures can trigger cardioprotection including conditionings (exposure to brief episodes of ischaemia-reperfusion to protect against sustained ischaemia-reperfusion), hypoxia, adenosine, acetylcholine, adrenomedullin, angiotensin, bradykinin, catecholamines, endothelin, estrogens, phenylephrine, opioids, testosterone, and many more. These triggers activate many intracellular signalling factors including protein kinases, different enzymes, transcription factors and defined signalling pathways to target structures in mitochondria, sarcoplasmic reticulum, nucleus and sarcolemma to mediate cardioprotection. Although a lot of information about cardioprotection has been acquired, there are still two major outstanding issues to be addressed in the future 1) better understanding of spatio-temporal relationships between signalling elements, and; 2) devising therapeutic strategies against myocardial diseases based on cardioprotective signalling. Further research is required to paint integral picture of cardioprotective signalling and more clinical studies are required to properly test clinical efficacy and safety of potential cardioprotective strategies. Therapies against cardiac diseases based on cardioprotective strategies would be a perfect adjunct to current therapeutic strategies based on restitution of coronary blood flow and regulation of myocardial metabolic demands.
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Affiliation(s)
- Aleksandar Jovanović
- University of Nicosia Medical School, 21 Ilia Papakyriakou, 2414 Engomi, P.O. Box 24005, CY-1700 Nicosia, Cyprus.
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115
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Yang Y, Ren J, Sun Y, Xue Y, Zhang Z, Gong A, Wang B, Zhong Z, Cui Z, Xi Z, Yang GY, Sun Q, Bian L. A connexin43/YAP axis regulates astroglial-mesenchymal transition in hemoglobin induced astrocyte activation. Cell Death Differ 2018; 25:1870-1884. [PMID: 29880858 DOI: 10.1038/s41418-018-0137-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 04/12/2018] [Accepted: 05/16/2018] [Indexed: 01/05/2023] Open
Abstract
Reactive astrogliosis is a common response to insults to the central nervous system, but the mechanism remains unknown. In this study, we found the temporal and spatial differential expression of glial fibrillary acidic protein (GFAP) and Vimentin in the intracerebral hemorrhage (ICH) mouse brain, indicating that the de-differentiation and astroglial-mesenchymal transition (AMT) of astrocytes might be an early event in reactive astrogliosis. Further we verified the AMT finding in purified astrocyte cultures exposed to hemoglobin (Hb). Additionally, Connexin 43 (Cx43) downregulation and YAP nuclear translocation were observed in Hb-activated astrocytes. Knocking down Cx43 by siRNA triggered YAP nuclear translocation. Cx43 and YAP were physically associated as determined by immunofluorescence and co-immunoprecipitation. We propose that astrocytes undergo AMT during Hb-induced activation where Cx43 downregulation facilitates YAP nuclear translocation is a novel mechanism involved in this process. Cx43-YAP interaction may represent a potential therapeutic target for modulating astrocyte activation.
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Affiliation(s)
- Yong Yang
- Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China.,Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Jie Ren
- Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Yuhao Sun
- Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Yuan Xue
- Zhenjiang Center for Disease Control and Prevention, Zhenjiang, 212000, China
| | - Zhijian Zhang
- Basic Medical Science Research Center, School of Medicine, Jiangsu University, Zhenjiang, 212000, China
| | - Aihua Gong
- Basic Medical Science Research Center, School of Medicine, Jiangsu University, Zhenjiang, 212000, China
| | - Baofeng Wang
- Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Zhihong Zhong
- Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Zhenwen Cui
- Department of Neurosurgery, The Affiliated Hospital of Qingdao University, Qingdao, 266000, China
| | - Zhiyu Xi
- Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Guo-Yuan Yang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Qingfang Sun
- Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China. .,Department of Neurosurgery, Ruijin Hospital Luwan Branch, Shanghai Jiao Tong University, Shanghai, 200025, China.
| | - Liuguan Bian
- Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China.
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116
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Iyyathurai J, Wang N, D'hondt C, Jiang JX, Leybaert L, Bultynck G. The SH3-binding domain of Cx43 participates in loop/tail interactions critical for Cx43-hemichannel activity. Cell Mol Life Sci 2018; 75:2059-2073. [PMID: 29218600 PMCID: PMC6318120 DOI: 10.1007/s00018-017-2722-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 11/24/2017] [Accepted: 11/27/2017] [Indexed: 12/19/2022]
Abstract
Connexin 43 (Cx43) hemichannels establish local signaling networks via the release of ATP and other molecules, but their excessive opening may result in cell death. Hence, the activity of Cx43-hemichannels ought to be critically controlled. This involves interactions between the C-terminal tail (CT) and the cytoplasmic loop (CL), more particularly the L2 domain within CL. Previous work revealed an important role for the last nine amino acids of the Cx43 CT by targeting the L2 domain, as these nine amino acids were sufficient to restore the activity of CT-truncated Cx43-hemichannels. However, we discovered that deletion of the last 19 amino acids of the CT only partially lowered the binding to the L2 domain, indicating that a second L2-binding region is present in the CT. We here provide evidence that the SH3-binding domain is another CT region that targets the L2 domain. At the functional level, the SH3-binding domain was able to restore the activity of CT-truncated Cx43-hemichannels and alleviate the inhibition of full-length Cx43-hemichannels by high intracellular Ca2+ concentration ([Ca2+]i) as demonstrated by various approaches including patch clamp studies of unitary Cx43-hemichannel activity. Finally, we show that in full-length Cx43-hemichannels, deletion of either the SH3-binding domain or the CT9 region suppresses the hemichannel activity, while deletion of both domains completely annihilates the hemichannel activity. These results demonstrate that the Cx43 SH3-binding domain, in addition to the CT9 region, critically controls hemichannel activity at high [Ca2+]i, which may be involved in pathological hemichannel opening.
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Affiliation(s)
- Jegan Iyyathurai
- Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N-1 Bus 802, Herestraat 49, 3000, Louvain, Belgium
| | - Nan Wang
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium
| | - Catheleyne D'hondt
- Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N-1 Bus 802, Herestraat 49, 3000, Louvain, Belgium
| | - Jean X Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N-1 Bus 802, Herestraat 49, 3000, Louvain, Belgium.
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117
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Shvedova M, Anfinogenova Y, Popov SV, Atochin DN. Connexins and Nitric Oxide Inside and Outside Mitochondria: Significance for Cardiac Protection and Adaptation. Front Physiol 2018; 9:479. [PMID: 29867537 PMCID: PMC5964197 DOI: 10.3389/fphys.2018.00479] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/16/2018] [Indexed: 12/27/2022] Open
Abstract
Irreversible myocardial damage happens in the presence of prolonged and severe ischemia. Several phenomena protect the heart against myocardial infarction and other adverse outcomes of ischemia and reperfusion (IR), namely: hibernation related to stunned myocardium, ischemic preconditioning (IPC), ischemic post-conditioning, and their pharmacological surrogates. Ischemic preconditioning consists in the induction of a brief IR to reduce damage of the tissue caused by prolonged and severe ischemia. Nitric oxide (NO) signaling plays an essential role in IPC. Nitric oxide-sensitive guanylate cyclase/cyclic guanosine-3′,5′-monophosphate (cGMP)-dependent protein kinase type I-signaling pathway protects against the IR injury during myocardial infarction. Mitochondrial ATP-sensitive and Ca2+-activated K+ channels are involved in NO-mediated signaling in IPC. Independently of the cGMP-mediated induction of NO production, S-nitrosation represents a regulatory molecular mechanism similar to phosphorylation and is essential for IPC. Unlike conditioning phenomena, the mechanistic basis of myocardial stunning and hibernation remains poorly understood. In this review article, we hypothesize that the disruption of electrical syncytium of the myocardium may underly myocardial stunning and hibernation. Considering that the connexins are the building blocks of gap junctions which represent primary structural basis of electrical syncytium, we discuss data on the involvement of connexins into myocardial conditioning, stunning, and hibernation. We also show how NO-mediated signaling is involved in myocardial stunning and hibernation. Connexins represent an essential element of adaptation phenomena of the heart at the level of both the cardio- myocytes and the mitochondria. Nitric oxide targets mitochondrial connexins which may affect electrical syncytium continuum in the heart. Mitochondrial connexins may play an essential role in NO-dependent mechanisms of myocardial adaptation to ischemia.
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Affiliation(s)
- Maria Shvedova
- Cardiovascular Research Center and Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
| | - Yana Anfinogenova
- Cardiology Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia.,RASA Center, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - Sergey V Popov
- Cardiology Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia
| | - Dmitriy N Atochin
- Cardiovascular Research Center and Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States.,RASA Center, National Research Tomsk Polytechnic University, Tomsk, Russia
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118
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Anupama N, Sindhu G, Raghu KG. Significance of mitochondria on cardiometabolic syndromes. Fundam Clin Pharmacol 2018; 32:346-356. [DOI: 10.1111/fcp.12359] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 01/12/2018] [Accepted: 02/12/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Nair Anupama
- Agroprocessing and Technology Division; CSIR -National Institute for Interdisciplinary Science and Technology (NIIST); Industrial estate P.O., Pappanamcode Thiruvananthapuram 695019 Kerala India
| | - Ganapathy Sindhu
- Agroprocessing and Technology Division; CSIR -National Institute for Interdisciplinary Science and Technology (NIIST); Industrial estate P.O., Pappanamcode Thiruvananthapuram 695019 Kerala India
| | - Kozhiparambil Gopalan Raghu
- Agroprocessing and Technology Division; CSIR -National Institute for Interdisciplinary Science and Technology (NIIST); Industrial estate P.O., Pappanamcode Thiruvananthapuram 695019 Kerala India
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119
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Aasen T, Johnstone S, Vidal-Brime L, Lynn KS, Koval M. Connexins: Synthesis, Post-Translational Modifications, and Trafficking in Health and Disease. Int J Mol Sci 2018; 19:ijms19051296. [PMID: 29701678 PMCID: PMC5983588 DOI: 10.3390/ijms19051296] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/20/2018] [Accepted: 04/21/2018] [Indexed: 02/06/2023] Open
Abstract
Connexins are tetraspan transmembrane proteins that form gap junctions and facilitate direct intercellular communication, a critical feature for the development, function, and homeostasis of tissues and organs. In addition, a growing number of gap junction-independent functions are being ascribed to these proteins. The connexin gene family is under extensive regulation at the transcriptional and post-transcriptional level, and undergoes numerous modifications at the protein level, including phosphorylation, which ultimately affects their trafficking, stability, and function. Here, we summarize these key regulatory events, with emphasis on how these affect connexin multifunctionality in health and disease.
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Affiliation(s)
- Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain.
| | - Scott Johnstone
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VI 22908, USA.
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TT, UK.
| | - Laia Vidal-Brime
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain.
| | - K Sabrina Lynn
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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120
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Wang Q, Wang Z, Tian Y, Zhang H, Fang Y, Yu Z, Wang W, Xie M, Ding F. Inhibition of Astrocyte Connexin 43 Channels Facilitates the Differentiation of Oligodendrocyte Precursor Cells Under Hypoxic Conditions In Vitro. J Mol Neurosci 2018; 64:591-600. [PMID: 29623602 PMCID: PMC6763517 DOI: 10.1007/s12031-018-1061-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 03/06/2018] [Indexed: 12/15/2022]
Abstract
Oligodendrocyte precursor cells (OPCs) proliferation and differentiation are essential for remyelination after white matter injury. Astrocytes could promote oligodendrogenesis after white matter damage whereas the underlying mechanisms are unknown. In this study, the role of astrocytic connexin43 (Cx43) hemichannels involved in OPC proliferation and differentiation in chronic hypoxia was evaluated. In an astrocyte-OPC co-culture chronic hypoxia model, OPCs became proliferative but failed to mature into oligodendrocytes. Application of astrocytic Cx43 blockers attenuated astrocyte activation, suppressed Cx43 hemichannel uptake activity and glutamate release induced by hypoxia, as well as improved OPC differentiation. Moreover, AMPA but not NMDA glutamate receptor antagonist rescued OPC differentiation in hypoxia. In conclusion, these findings suggested that astrocytic Cx43 hemichannel inhibition could potentially improve OPC maturation by attenuating AMPAR-mediated glutamate signaling. Astrocytic Cx43 hemichannels could serve as a potential therapeutic target for remyelination after chronic hypoxia.
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Affiliation(s)
- Qiong Wang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Zhen Wang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Yeye Tian
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Huaqiu Zhang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Yongkang Fang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Zhiyuan Yu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Wei Wang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.,Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Minjie Xie
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.,Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Fengfei Ding
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.
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121
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Abstract
Major depressive disorder (MDD) is a chronic and debilitating illness that affects over 350 million people worldwide; however, current treatments have failed to cure or prevent the progress of depression. Increasing evidence suggests a crucial role for connexins in MDD. In this review, we have summarised recent accomplishments regarding the role of connexins, gap junctions, and hemichannels in the aetiology of MDD, and discussed the limitations of current research. A blockage of gap junctions or hemichannels induces depressive behaviour. Possible underlying mechanisms include the regulation of neurosecretory functions and synaptic activity by gap junctions and hemichannels. Gap junctions are functionally inhibited under stress conditions. Conversely, hemichannel permeability is increased. Antidepressants inhibit hemichannel permeability; however, they have contrasting effects on the function of gap junctions under normal conditions and can protect them against stress. In conclusion, the blockage of hemichannels concurrent with improvements in gap junction functionality might be potential targets for depression treatment.
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Affiliation(s)
- Cong-Yuan Xia
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Zhen-Zhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Tohru Yamakuni
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; College of Pharmacy, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China.
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122
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Yin X, Feng L, Ma D, Yin P, Wang X, Hou S, Hao Y, Zhang J, Xin M, Feng J. Roles of astrocytic connexin-43, hemichannels, and gap junctions in oxygen-glucose deprivation/reperfusion injury induced neuroinflammation and the possible regulatory mechanisms of salvianolic acid B and carbenoxolone. J Neuroinflammation 2018; 15:97. [PMID: 29587860 PMCID: PMC5872583 DOI: 10.1186/s12974-018-1127-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/12/2018] [Indexed: 02/07/2023] Open
Abstract
Background Glia-mediated neuroinflammation is related to brain injury exacerbation after cerebral ischemia/reperfusion (I/R) injury. Astrocytic hemichannels or gap junctions, which were mainly formed by connexin-43, have been implicated in I/R damage. However, the exact roles of astrocytic hemichannels and gap junction in neuroinflammatory responses induced by I/R injury remain unknown. Methods Primary cultured astrocytes were subjected to OGD/R injury, an in vitro model of I/R injury. Salvianolic acid B (SalB) or carbenoxolone (CBX) were applied for those astrocytes. Besides, Cx43 mimetic peptides Gap19 or Gap26 were also applied during OGD/R injury; Cx43 protein levels were determined by western blot and cytoimmunofluorescene staining, hemichannel activities by Ethidium bromide uptake and ATP concentration detection, and gap junction intercellular communication (GJIC) permeability by parachute assay. Further, astrocyte-conditioned medium (ACM) was collected and incubated with microglia. Meanwhile, ATP or apyrase were applied to explore the role of ATP during OGD/R injury. Microglial activation, M1/M2 phenotypes, and M1/M2-related cytokines were detected. Also, microglia-conditioned medium (MEM) was collected and incubated with astrocytes to further investigate its influence on astrocytic hemichannel activity and GJIC permeability. Lastly, effects of ACM and MCM on neuronal viability were detected by flow cytometry. Results We found that OGD/R induced abnormally opened hemichannels with increased ATP release and EtBr uptake but reduced GJIC permeability. WB tests showed decreased astrocytic plasma membrane’s Cx43, while showing an increase in cytoplasma. Treating OGD/R-injured microglia with ATP or OGD/R-ACM induced further microglial activation and secondary pro-inflammatory cytokine release, with the M1 phenotype predominating. Conversely, astrocytes incubated with OGD/R-MCM exhibited increased hemichannel opening but reduced GJIC coupling. Both SalB and CBX inhibited abnormal astrocytic hemichannel opening and ATP release and switched the activated microglial phenotype from M1 to M2, thus providing effective neuroprotection. Application of Gap19 or Gap26 showed similar results with CBX. We also found that OGD/R injury caused both plasma membrane p-Cx43(Ser265) and p-Src(Tyr416) significantly upregulated; application of SalB may be inhibiting Src kinase and attenuating Cx43 internalization. Meanwhile, CBX treatment induced obviously downregulation of p-Cx43(Ser368) and p-PKC(Ser729) protein levels in plasma membrane. Conclusions We propose a vicious cycle exists between astrocytic hemichannel and microglial activation after OGD/R injury, which would aggravate neuroinflammatory responses and neuronal damage. Astrocytic Cx43, hemichannels, and GJIC play critical roles in OGD/R injury-induced neuroinflammatory responses; treatment differentially targeting astrocytic Cx43, hemichannels, and GJIC may provide novel avenues for therapeutics during cerebral I/R injury. Electronic supplementary material The online version of this article (10.1186/s12974-018-1127-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiang Yin
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Liangshu Feng
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Di Ma
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Ping Yin
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Xinyu Wang
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Shuai Hou
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Yulei Hao
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Jingdian Zhang
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Meiying Xin
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Jiachun Feng
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China.
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123
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Shi W, Riquelme MA, Gu S, Jiang JX. Connexin hemichannels mediate glutathione transport and protect lens fiber cells from oxidative stress. J Cell Sci 2018; 131:jcs212506. [PMID: 29487175 PMCID: PMC5897712 DOI: 10.1242/jcs.212506] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 02/07/2018] [Indexed: 01/04/2023] Open
Abstract
Elevated oxidized stress contributes to lens cataracts, and gap junctions play important roles in maintaining lens transparency. As well as forming gap junctions, connexin (Cx) proteins also form hemichannels. Here, we report a new mechanism whereby hemichannels mediate transport of reductant glutathione into lens fiber cells and protect cells against oxidative stress. We found that Cx50 (also known as GJA8) hemichannels opened in response to H2O2 in lens fiber cells but that transport through the channels was inhibited by two dominant-negative mutants in Cx50, Cx50P88S, which inhibits transport through both gap junctions and hemichannels, and Cx50H156N, which only inhibits transport through hemichannels and not gap junctions. Treatment with H2O2 increased the number of fiber cells undergoing apoptosis, and this increase was augmented with dominant-negative mutants that disrupted both hemichannels formed from Cx46 (also known as GJA3) and Cx50, while Cx50E48K, which only impairs gap junctions, did not have such an effect. Moreover, hemichannels mediate uptake of glutathione, and this uptake protected lens fiber cells against oxidative stress, while hemichannels with impaired transport had less protective benefit from glutathione. Taken together, these results show that oxidative stress activates connexin hemichannels in the lens fiber cells and that hemichannels likely protect lens cell against oxidative damage through transporting extracellular reductants.
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Affiliation(s)
- Wen Shi
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha 410000, China
| | - Manuel A Riquelme
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
| | - Sumin Gu
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
| | - Jean X Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
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Johnson RD, Camelliti P. Role of Non-Myocyte Gap Junctions and Connexin Hemichannels in Cardiovascular Health and Disease: Novel Therapeutic Targets? Int J Mol Sci 2018; 19:ijms19030866. [PMID: 29543751 PMCID: PMC5877727 DOI: 10.3390/ijms19030866] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 03/10/2018] [Accepted: 03/12/2018] [Indexed: 12/24/2022] Open
Abstract
The heart is a complex organ composed of multiple cell types, including cardiomyocytes and different non-myocyte populations, all working closely together to determine the hearts properties and maintain normal cardiac function. Connexins are abundantly expressed proteins that form plasma membrane hemichannels and gap junctions between cells. Gap junctions are intracellular channels that allow for communication between cells, and in the heart they play a crucial role in cardiac conduction by coupling adjacent cardiomyocytes. Connexins are expressed in both cardiomyocytes and non-myocytes, including cardiac fibroblasts, endothelial cells, and macrophages. Non-myocytes are the largest population of cells in the heart, and therefore it is important to consider what roles connexins, hemichannels, and gap junctions play in these cell types. The aim of this review is to provide insight into connexin-based signalling in non-myocytes during health and disease, and highlight how targeting these proteins could lead to the development of novel therapies. We conclude that connexins in non-myocytes contribute to arrhythmias and adverse ventricular remodelling following myocardial infarction, and are associated with the initiation and development of atherosclerosis. Therefore, therapeutic interventions targeting these connexins represent an exciting new research avenue with great potential.
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Affiliation(s)
- Robert D Johnson
- School of Biosciences and Medicine, University of Surrey, Guildford GU2 7XH, UK.
| | - Patrizia Camelliti
- School of Biosciences and Medicine, University of Surrey, Guildford GU2 7XH, UK.
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125
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Abstract
Atrial septal defect is one of the most common CHD. The pathogenesis of atrial septal defect still remains unknown. Cx43 is the most prevalent connexin in the mammalian heart during development. Its genetic variants can cause several CHD. The aim of our study was to investigate the association of genetic variations of the Cx43 with sporadic atrial septal defect. A total of 450 paediatric patients were recruited, including 150 cases with atrial septal defect and 300 healthy controls. The promoter region of Cx43 was analysed by sequencing after polymerase chain reaction. All data were analysed by using the Statistic Package for Social Science 19.0 software. The frequency of the single nucleotide polymorphism rs2071166 was significantly higher in atrial septal defect cases than in healthy controls. The CC genotype at rs2071166 site in Cx43 was correlated with an increased risk for atrial septal defect (p<0.0001, odds ratio=3.891, 95% confidence interval 1.948-7.772) and the C allele was positively correlated with atrial septal defect (p=0.007, odds ratio=1.567, 95% confidence interval 1.129-2.175). In conclusion, our results confirmed that rs2071166 in Cx43 may be relevant with an increased atrial septal defect risk.
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126
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Heusch G, Gersh BJ. The pathophysiology of acute myocardial infarction and strategies of protection beyond reperfusion: a continual challenge. Eur Heart J 2018; 38:774-784. [PMID: 27354052 DOI: 10.1093/eurheartj/ehw224] [Citation(s) in RCA: 273] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/12/2016] [Indexed: 12/15/2022] Open
Abstract
The incidence of ST segment elevation myocardial infarction (STEMI) has decreased over the last two decades in developed countries, but mortality from STEMI despite widespread access to reperfusion therapy is still substantial as is the development of heart failure, particularly among an expanding older population. In developing countries, the incidence of STEMI is increasing and interventional reperfusion is often not available. We here review the pathophysiology of acute myocardial infarction and reperfusion, notably the temporal and spatial evolution of ischaemic and reperfusion injury, the different modes of cell death, and the resulting coronary microvascular dysfunction. We then go on to briefly characterize the cardioprotective phenomena of ischaemic preconditioning, ischaemic postconditioning, and remote ischaemic conditioning and their underlying signal transduction pathways. We discuss in detail the attempts to translate conditioning strategies and drug therapy into the clinical setting. Most attempts have failed so far to reduce infarct size and improve clinical outcomes in STEMI patients, and we discuss potential reasons for such failure. Currently, it appears that remote ischaemic conditioning and a few drugs (atrial natriuretic peptide, exenatide, metoprolol, and esmolol) reduce infarct size, but studies with clinical outcome as primary endpoint are still underway.
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Affiliation(s)
- Gerd Heusch
- Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Hufelandstr. 55, 45122 Essen, Germany
| | - Bernard J Gersh
- Division of Cardiovascular Diseases, Mayo Clinic and Mayo Clinic College of Medicine, Rochester, MN, USA
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127
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Li W, Bao G, Chen W, Qiang X, Zhu S, Wang S, He M, Ma G, Ochani M, Al-Abed Y, Yang H, Tracey KJ, Wang P, D'Angelo J, Wang H. Connexin 43 Hemichannel as a Novel Mediator of Sterile and Infectious Inflammatory Diseases. Sci Rep 2018; 8:166. [PMID: 29317708 PMCID: PMC5760527 DOI: 10.1038/s41598-017-18452-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 12/12/2017] [Indexed: 12/29/2022] Open
Abstract
Cytoplasmic membrane-bound connexin 43 (Cx43) proteins oligomerize into hexameric channels (hemichannels) that can sometimes dock with hemichannels on adjacent cells to form gap junctional (GJ) channels. However, the possible role of Cx43 hemichannels in sterile and infectious inflammatory diseases has not been adequately defined due to the lack of selective interventions. Here we report that a proinflammatory mediator, the serum amyloid A (SAA), resembled bacterial endotoxin by stimulating macrophages to up-regulate Cx43 expression and double-stranded RNA-activated protein kinase R (PKR) phosphorylation in a TLR4-dependent fashion. Two well-known Cx43 mimetic peptides, the GAP26 and TAT-GAP19, divergently affected macrophage hemichannel activities in vitro, and differentially altered the outcome of lethal sepsis in vivo. By screening a panel of Cx43 mimetic peptides, we discovered that one cysteine-containing peptide, P5 (ENVCYD), effectively attenuated hemichannel activities, and significantly suppressed endotoxin-induced release of ATP and HMGB1 in vitro. In vivo, the P5 peptide conferred a significant protection against hepatic ischemia/reperfusion injury and lethal microbial infection. Collectively, these findings have suggested a pathogenic role of Cx43 hemichannels in sterile injurious as well as infectious inflammatory diseases possibly through facilitating extracellular ATP efflux to trigger PKR phosphorylation/activation.
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Affiliation(s)
- Wei Li
- Department of Emergency Medicine, North Shore University Hospital, Northwell Health, Manhasset, NY, 11030, USA. .,The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. .,International Laboratory for Sepsis Research, Huaihe Hospital, Henan University, Kaifeng, Henan, 475000, China.
| | - Guoqiang Bao
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA.,Department of General Surgery, Tangdu Hospital, The 4th Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Weiqiang Chen
- Department of Emergency Medicine, North Shore University Hospital, Northwell Health, Manhasset, NY, 11030, USA.,The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Xiaoling Qiang
- Department of Emergency Medicine, North Shore University Hospital, Northwell Health, Manhasset, NY, 11030, USA.,The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Shu Zhu
- Department of Emergency Medicine, North Shore University Hospital, Northwell Health, Manhasset, NY, 11030, USA.,The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Shuaiwei Wang
- International Laboratory for Sepsis Research, Huaihe Hospital, Henan University, Kaifeng, Henan, 475000, China
| | - Mingzhu He
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Gaifeng Ma
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Mahendar Ochani
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Yousef Al-Abed
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Huan Yang
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Kevin J Tracey
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Ping Wang
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - John D'Angelo
- Department of Emergency Medicine, North Shore University Hospital, Northwell Health, Manhasset, NY, 11030, USA
| | - Haichao Wang
- Department of Emergency Medicine, North Shore University Hospital, Northwell Health, Manhasset, NY, 11030, USA. .,The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA.
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128
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Galinsky R, Davidson JO, Dean JM, Green CR, Bennet L, Gunn AJ. Glia and hemichannels: key mediators of perinatal encephalopathy. Neural Regen Res 2018; 13:181-189. [PMID: 29557357 PMCID: PMC5879879 DOI: 10.4103/1673-5374.226378] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Perinatal encephalopathy remains a major cause of disability, such as cerebral palsy. Therapeutic hypothermia is now well established to partially reduce risk of disability in late preterm/term infants. However, new and complementary therapeutic targets are needed to further improve outcomes. There is increasing evidence that glia play a key role in neural damage after hypoxia-ischemia and infection/inflammation. In this review, we discuss the role of astrocytic gap junction (connexin) hemichannels in the spread of neural injury after hypoxia-ischemia and/or infection/inflammation. Potential mechanisms of hemichannel mediated injury likely involve impaired intracellular calcium handling, loss of blood-brain barrier integrity and release of adenosine triphosphate (ATP) resulting in over-activation of purinergic receptors. We propose the hypothesis that inflammation-induced opening of connexin hemichannels is a key regulating event that initiates a vicious cycle of excessive ATP release, which in turn propagates activation of purinergic receptors on microglia and astrocytes. This suggests that developing new neuroprotective strategies for preterm infants will benefit from a detailed understanding of glial and connexin hemichannel responses.
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Affiliation(s)
- Robert Galinsky
- Department of Physiology, University of Auckland, Auckland, New Zealand; The Ritchie Centre, Hudson Institute of Medical Research, Victoria, Australia
| | - Joanne O Davidson
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Justin M Dean
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology, University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Department of Physiology, University of Auckland, Auckland, New Zealand
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129
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Sun JB, Li Y, Cai YF, Huang Y, Liu S, Yeung PK, Deng MZ, Sun GS, Zilundu PL, Hu QS, An RX, Zhou LH, Wang LX, Cheng X. Scutellarin protects oxygen/glucose-deprived astrocytes and reduces focal cerebral ischemic injury. Neural Regen Res 2018; 13:1396-1407. [PMID: 30106052 PMCID: PMC6108207 DOI: 10.4103/1673-5374.235293] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Scutellarin, a bioactive flavone isolated from Scutellaria baicalensis, has anti-inflammatory, anti-neurotoxic, anti-apoptotic and anti-oxidative effects and has been used to treat cardiovascular and cerebrovascular diseases in China. However, the mechanisms by which scutellarin mediates neuroprotection in cerebral ischemia remain unclear. The interaction between scutellarin and nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) was assessed by molecular docking study, which showed that scutellarin selectively binds to NOX2 with high affinity. Cultures of primary astrocytes isolated from the cerebral cortex of neonatal Sprague-Dawley rats were pretreated with 2, 10 or 50 μM scutellarin for 30 minutes. The astrocytes were then subjected to oxygen/glucose deprivation by incubation for 2 hours in glucose-free Dulbecco's modified Eagle's medium in a 95% N2/5% CO2 incubator, followed by simulated reperfusion for 22 hours. Cell viability was assessed by cell counting kit-8 assay. Expression levels of NOX2, connexin 43 and caspase-3 were assessed by western blot assay. Reactive oxygen species were measured spectrophotometrically. Pretreatment with 10 or 50 μM scutellarin substantially increased viability, reduced the expression of NOX2 and caspase-3, increased the expression of connexin 43, and diminished the levels of reactive oxygen species in astrocytes subjected to ischemia-reperfusion. We also assessed the effects of scutellarin in vivo in the rat transient middle cerebral artery occlusion model of cerebral ischemia-reperfusion injury. Rats were given intraperitoneal injection of 100 mg/kg scutellarin 2 hours before surgery. The Bederson scale was used to assess neurological deficit, and 2,3,5-triphenyltetrazolium chloride staining was used to measure infarct size. Western blot assay was used to assess expression of NOX2 and connexin 43 in brain tissue. Enzyme-linked immunosorbent assay was used to detect 8-hydroxydeoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal (4-HNE) and 3-nitrotyrosin (3-NT) in brain tissue. Immunofluorescence double staining was used to determine the co-expression of caspase-3 and NeuN. Pretreatment with scutellarin improved the neurological function of rats with focal cerebral ischemia, reduced infarct size, diminished the expression of NOX2, reduced levels of 8-OHdG, 4-HNE and 3-NT, and reduced the number of cells co-expressing caspase-3 and NeuN in the injured brain tissue. Furthermore, we examined the effect of the NOX2 inhibitor apocynin. Apocynin substantially increased connexin 43 expression in vivo and in vitro. Collectively, our findings suggest that scutellarin protects against ischemic injury in vitro and in vivo by downregulating NOX2, upregulating connexin 43, decreasing oxidative damage, and reducing apoptotic cell death.
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Affiliation(s)
- Jing-Bo Sun
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine; Department of Second Institute of Clinical Medicine, Guangzhou University of Traditional Chinese Medicine; Guangdong Provincial Academy of Chinese Medical Sciences; Guangdong Provincial Chinese Emergency Key Laboratory, Guangzhou, Guangdong Province, China
| | - Yan Li
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine; Department of Second Institute of Clinical Medicine, Guangzhou University of Traditional Chinese Medicine; Guangdong Provincial Academy of Chinese Medical Sciences; Guangdong Provincial Chinese Emergency Key Laboratory, Guangzhou, Guangdong Province, China
| | - Ye-Feng Cai
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine; Department of Second Institute of Clinical Medicine, Guangzhou University of Traditional Chinese Medicine; Guangdong Provincial Academy of Chinese Medical Sciences; Guangdong Provincial Chinese Emergency Key Laboratory, Guangzhou, Guangdong Province, China
| | - Yan Huang
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine; Department of Second Institute of Clinical Medicine, Guangzhou University of Traditional Chinese Medicine; Guangdong Provincial Academy of Chinese Medical Sciences; Guangdong Provincial Chinese Emergency Key Laboratory, Guangzhou, Guangdong Province, China
| | - Shu Liu
- Department of Anatomy, An Hui Medical University, Hefei, Anhui Province, China
| | - Patrick Kk Yeung
- Department of Biomedical Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Min-Zhen Deng
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine; Department of Second Institute of Clinical Medicine, Guangzhou University of Traditional Chinese Medicine; Guangdong Provincial Academy of Chinese Medical Sciences; Guangdong Provincial Chinese Emergency Key Laboratory, Guangzhou, Guangdong Province, China
| | - Guang-Shun Sun
- Department of Preventive Medicine, School of Public Health, Zhong Shan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Prince Lm Zilundu
- Guangzhou Department of Anatomy, Zhong Shan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Qian-Sheng Hu
- Department of Preventive Medicine, School of Public Health, Zhong Shan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Rui-Xin An
- Guangzhou Department of Anatomy, Zhong Shan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Li-Hua Zhou
- Guangzhou Department of Anatomy, Zhong Shan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Li-Xin Wang
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine; Department of Second Institute of Clinical Medicine, Guangzhou University of Traditional Chinese Medicine; Guangdong Provincial Academy of Chinese Medical Sciences; Guangdong Provincial Chinese Emergency Key Laboratory, Guangzhou, Guangdong Province, China
| | - Xiao Cheng
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine; Department of Second Institute of Clinical Medicine, Guangzhou University of Traditional Chinese Medicine; Guangdong Provincial Academy of Chinese Medical Sciences; Guangdong Provincial Chinese Emergency Key Laboratory, Guangzhou, Guangdong Province, China
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130
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Vicario N, Zappalà A, Calabrese G, Gulino R, Parenti C, Gulisano M, Parenti R. Connexins in the Central Nervous System: Physiological Traits and Neuroprotective Targets. Front Physiol 2017; 8:1060. [PMID: 29326598 PMCID: PMC5741605 DOI: 10.3389/fphys.2017.01060] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 12/04/2017] [Indexed: 01/22/2023] Open
Abstract
Cell-to-cell interaction and cell-to-extracellular environment communication are emerging as new therapeutic targets in neurodegenerative disorders. Dynamic expression of connexins leads to distinctive hemichannels and gap junctions, characterized by cell-specific conduction, exchange of stimuli or metabolites, and particular channel functions. Herein, we briefly reviewed classical physiological traits and functions of connexins, hemichannels, and gap junctions, in order to discuss the controversial role of these proteins and their mediated interactions during neuroprotection, with a particular focus on Cx43-based channels. We pointed out the contribution of connexins in neural cells populations during neurodegenerative processes to explore potential neuroprotective therapeutic applications.
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Affiliation(s)
- Nunzio Vicario
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Agata Zappalà
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Giovanna Calabrese
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Rosario Gulino
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Carmela Parenti
- Department of Drug Sciences, University of Catania, Catania, Italy
| | - Massimo Gulisano
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.,Department of Drug Sciences, University of Catania, Catania, Italy
| | - Rosalba Parenti
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
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131
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Malik S, Theis M, Eugenin EA. Connexin43 Containing Gap Junction Channels Facilitate HIV Bystander Toxicity: Implications in NeuroHIV. Front Mol Neurosci 2017; 10:404. [PMID: 29259541 PMCID: PMC5723329 DOI: 10.3389/fnmol.2017.00404] [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: 08/01/2017] [Accepted: 11/21/2017] [Indexed: 02/02/2023] Open
Abstract
Human immunodeficiency virus-1 (HIV-1) infection compromises the central nervous system (CNS) in a significant number of infected individuals, resulting in neurological dysfunction that ranges from minor cognitive deficits to frank dementia. While macrophages/microglia are the predominant CNS cells infected by HIV, our laboratory and others have shown that HIV-infected astrocytes, although present in relatively low numbers with minimal to undetectable viral replication, play key role in NeuroAIDS pathogenesis. Our laboratory has identified that HIV "hijacks" connexin (Cx) containing channels, such as gap junctions (GJs) and hemichannels (HCs), to spread toxicity and apoptosis to uninfected cells even in the absence of active viral replication. In this study, using a murine model with an astrocyte-directed deletion of Cx43 gene (hGFAP-cre Cx43fl/fl) and control Cx43fl/fl mice, we examined whether few HIV-infected human astrocytoma cells (U87-CD4-CCR5), microinjected into the mouse cortex, can spread toxicity and apoptosis through GJ-mediated mechanisms, into the mouse cells, which are resistant to HIV infection. In the control Cx43fl/fl mice, microinjection of HIV-infected U87-CD4-CCR5 cells led to apoptosis in 84.28 ± 6.38% of mouse brain cells around the site of microinjection, whereas hGFAP-cre Cx43fl/fl mice exhibited minimal apoptosis (2.78 ± 1.55%). However, simultaneous injection of GJ blocker, 18α-glycyrrhetinic acid, and Cx43 blocking peptide along with microinjection of HIV-infected cells prevented apoptosis in Cx43fl/fl mice, demonstrating the Cx43 is essential for HIV-induced bystander toxicity. In conclusion, our findings demonstrate that Cx43 expression, and formation of GJs is essential for bystander apoptosis during HIV infection. These findings reveal novel potential therapeutic targets to reduce astrocyte-mediated bystander toxicity in HIV-infected individuals because despite low to undetectable viral replication in the CNS, Cx channels hijacked by HIV amplify viral neuropathogenesis.
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Affiliation(s)
- Shaily Malik
- Public Health Research Institute (PHRI), Newark, NJ, United States.,Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Martin Theis
- Institute of Cellular Neurosciences, University of Bonn, Bonn, Germany
| | - Eliseo A Eugenin
- Public Health Research Institute (PHRI), Newark, NJ, United States.,Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States
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132
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Russell J, Du Toit EF, Peart JN, Patel HH, Headrick JP. Myocyte membrane and microdomain modifications in diabetes: determinants of ischemic tolerance and cardioprotection. Cardiovasc Diabetol 2017; 16:155. [PMID: 29202762 PMCID: PMC5716308 DOI: 10.1186/s12933-017-0638-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 11/22/2017] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular disease, predominantly ischemic heart disease (IHD), is the leading cause of death in diabetes mellitus (DM). In addition to eliciting cardiomyopathy, DM induces a ‘wicked triumvirate’: (i) increasing the risk and incidence of IHD and myocardial ischemia; (ii) decreasing myocardial tolerance to ischemia–reperfusion (I–R) injury; and (iii) inhibiting or eliminating responses to cardioprotective stimuli. Changes in ischemic tolerance and cardioprotective signaling may contribute to substantially higher mortality and morbidity following ischemic insult in DM patients. Among the diverse mechanisms implicated in diabetic impairment of ischemic tolerance and cardioprotection, changes in sarcolemmal makeup may play an overarching role and are considered in detail in the current review. Observations predominantly in animal models reveal DM-dependent changes in membrane lipid composition (cholesterol and triglyceride accumulation, fatty acid saturation vs. reduced desaturation, phospholipid remodeling) that contribute to modulation of caveolar domains, gap junctions and T-tubules. These modifications influence sarcolemmal biophysical properties, receptor and phospholipid signaling, ion channel and transporter functions, contributing to contractile and electrophysiological dysfunction, cardiomyopathy, ischemic intolerance and suppression of protective signaling. A better understanding of these sarcolemmal abnormalities in types I and II DM (T1DM, T2DM) can inform approaches to limiting cardiomyopathy, associated IHD and their consequences. Key knowledge gaps include details of sarcolemmal changes in models of T2DM, temporal patterns of lipid, microdomain and T-tubule changes during disease development, and the precise impacts of these diverse sarcolemmal modifications. Importantly, exercise, dietary, pharmacological and gene approaches have potential for improving sarcolemmal makeup, and thus myocyte function and stress-resistance in this ubiquitous metabolic disorder.
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Affiliation(s)
- Jake Russell
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Eugene F Du Toit
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Jason N Peart
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Hemal H Patel
- VA San Diego Healthcare System and Department of Anesthesiology, University of California San Diego, San Diego, USA
| | - John P Headrick
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia. .,School of Medical Science, Griffith University, Southport, QLD, 4217, Australia.
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133
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Fiori MC, Krishnan S, Kjellgren A, Cuello LG, Altenberg GA. Inhibition by Commercial Aminoglycosides of Human Connexin Hemichannels Expressed in Bacteria. Molecules 2017; 22:molecules22122063. [PMID: 29186829 PMCID: PMC6149774 DOI: 10.3390/molecules22122063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 12/16/2022] Open
Abstract
In addition to gap junctional channels that mediate cell-to-cell communication, connexins form hemichannels that are present at the plasma membrane. Since hemichannels are permeable to small hydrophilic compounds, including metabolites and signaling molecules, their abnormal opening can cause or contribute to cell damage in disorders such as cardiac infarct, stroke, deafness, skin diseases, and cataracts. Therefore, hemichannels are potential pharmacological targets. A few aminoglycosides, well-known broad-spectrum antibiotics, have been shown to inhibit hemichannels. Here, we tested several commercially available aminoglycosides for inhibition of human connexin hemichannels using a cell-based bacterial growth complementation assay that we developed recently. We found that kanamycin A, kanamycin B, geneticin, neomycin, and paromomycin are effective inhibitors of hemichannels formed by connexins 26, 43, and 46 (Cx26, Cx43, and Cx46). Because of the >70 years of clinical experience with aminoglycosides and the fact that several of the aminoglycosides tested here have been used in humans, they are promising starting points for the development of effective connexin hemichannel inhibitors.
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Affiliation(s)
- Mariana C Fiori
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA.
| | - Srinivasan Krishnan
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA.
| | - Abbey Kjellgren
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA.
- Honors College, McClellan Hall, Box 41017, Texas Tech University, Lubbock, TX 79409-1017, USA.
| | - Luis G Cuello
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA.
| | - Guillermo A Altenberg
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA.
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134
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JAK2/STAT3 pathway is involved in the protective effects of epidermal growth factor receptor activation against cerebral ischemia/reperfusion injury in rats. Neurosci Lett 2017; 662:219-226. [PMID: 29061394 DOI: 10.1016/j.neulet.2017.10.037] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 10/16/2017] [Accepted: 10/19/2017] [Indexed: 12/14/2022]
Abstract
Cerebral ischemia and reperfusion is a common pathophysiologic process, which is involved in stroke and brain trauma. Recent studies revealed that activating epidermal growth factor receptor (EGFR) ameliorates cerebral ischemia/reperfusion (I/R) injury, however, the precise mechanisms remain to be illuminated. In this study, the neurological behavior was evaluated by Longa score. The infarct volume was performed by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining and the expression of p-EGFR, p-STAT3, connexin (Cx43), Bax and Bcl-2 were detected by Western blot. The neurological behavior and infarct volume were increased in rats with cerebral I/R injury. Epidermal growth factor (EGF) pretreatment significantly decreased neurological deficit and infarct volume. However, the antagonist of EGFR, AG1478 attenuated the EGF-induced reduction of neurological deficit and infarct volume. Moreover, the inhibitor of JAK2/STAT3, AG490 undermined the protective effects stimulated by activating EGFR in rats with I/R injury. In addition, EGF pretreatment increased the expression of Bcl-2 and reduced the expression of Bax and Cx43, and the effects were abolished after using AG1478 and AG490. These findings implicate that JAK2/STAT3 pathway plays the vital role in I/R injury protection from activating EGFR. And the neuroprotective effects may associate with inhibiting the Cx43 expression and the inhibition of apoptosis.
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135
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Progesterone Via its Type-A Receptor Promotes Myometrial Gap Junction Coupling. Sci Rep 2017; 7:13357. [PMID: 29042599 PMCID: PMC5645358 DOI: 10.1038/s41598-017-13488-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 09/20/2017] [Indexed: 12/17/2022] Open
Abstract
Effective labour contractions require synchronization of myometrial cells through gap junctions (GJs). Clasically, progesterone (P4) is known to inhibit the expression of connexin-43 (Cx43, major component of GJs) and GJ formation in myometrium. Our current study is based on a striking observation that challenges this dogma. We observed conspicuous differences in the intracellular localization of Cx43 protein in PRA versus PRB expressing myocytes. Thus in P4 stimulated PRA cells Cx43 protein forms GJs, whereas in PRB cells the forward trafficking of Cx43 and GJ formation is inhibited even when Cx43 is overexpressed. We found that P4, via PRA/B, differentially regulates Cx43 translation to generate a Cx43-20 K isoform, which facilitates the transport of full length Cx43 to plasma membrane. The P4 mediated regulation of Cx43 trafficking and GJ formation occurs via non-genomic pathway and involves the regulation of mTOR signaling since inhibition of this pathway restored the Cx43 trafficking defect in PRB cells. We propose that PRA is a master regulator of Cx43 expression, GJ formation and myocyte connectivity/synchronization for labour.
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136
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Leybaert L, Lampe PD, Dhein S, Kwak BR, Ferdinandy P, Beyer EC, Laird DW, Naus CC, Green CR, Schulz R. Connexins in Cardiovascular and Neurovascular Health and Disease: Pharmacological Implications. Pharmacol Rev 2017; 69:396-478. [PMID: 28931622 PMCID: PMC5612248 DOI: 10.1124/pr.115.012062] [Citation(s) in RCA: 171] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Connexins are ubiquitous channel forming proteins that assemble as plasma membrane hemichannels and as intercellular gap junction channels that directly connect cells. In the heart, gap junction channels electrically connect myocytes and specialized conductive tissues to coordinate the atrial and ventricular contraction/relaxation cycles and pump function. In blood vessels, these channels facilitate long-distance endothelial cell communication, synchronize smooth muscle cell contraction, and support endothelial-smooth muscle cell communication. In the central nervous system they form cellular syncytia and coordinate neural function. Gap junction channels are normally open and hemichannels are normally closed, but pathologic conditions may restrict gap junction communication and promote hemichannel opening, thereby disturbing a delicate cellular communication balance. Until recently, most connexin-targeting agents exhibited little specificity and several off-target effects. Recent work with peptide-based approaches has demonstrated improved specificity and opened avenues for a more rational approach toward independently modulating the function of gap junctions and hemichannels. We here review the role of connexins and their channels in cardiovascular and neurovascular health and disease, focusing on crucial regulatory aspects and identification of potential targets to modify their function. We conclude that peptide-based investigations have raised several new opportunities for interfering with connexins and their channels that may soon allow preservation of gap junction communication, inhibition of hemichannel opening, and mitigation of inflammatory signaling.
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Affiliation(s)
- Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Paul D Lampe
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Stefan Dhein
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Brenda R Kwak
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Peter Ferdinandy
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Eric C Beyer
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Dale W Laird
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Christian C Naus
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Colin R Green
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Rainer Schulz
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
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137
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Chen B, Sun L, Wu X, Ma J. Correlation between connexin and traumatic brain injury in patients. Brain Behav 2017; 7:e00770. [PMID: 28948071 PMCID: PMC5607540 DOI: 10.1002/brb3.770] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/08/2017] [Accepted: 06/14/2017] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Identification of molecular alterations of damaged tissue in patients with neurological disorders can provide novel insight and potential therapeutic target for treatment of the diseases. It has been suggested by animal studies that connexins (CXs), a family of gap junction proteins, could contribute to neuronal cell death and associate with neurological deficits during trauma-induced damage. Nevertheless, whether specific CXs are involved in traumatic brain injury (TBI) has remained unexplored in human patients. METHODS In a clinical setting, we performed a correlation study of 131 TBI patients who received brain surgery. CXs (including CX40, CX43, and CX45) were examined in the harvested brain tissues for studying the relationships with the Glasgow Coma Scale scores of the patients. RESULTS Specifically, the protein levels of CX43 (negatively) and CX40 (positively) are associated with the extent of disease severity. Meanwhile, the phosphorylation status of CX43 was strongly associated with the severe TBI patients who contain relatively high kinase activities of PKC (protein kinase C) and MAPK (mitogen-activated protein kinase), two possible activators for CX43 phosphorylation. CONCLUSION These data highlight that a cluster of connexin family gap junction proteins not previously studied in humans is significantly correlated with the disease progression of TBI.
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Affiliation(s)
| | - Liwei Sun
- Tianjin Huanhu Hospital Tianjin China
| | | | - Jun Ma
- School of Public Health Tianjin Medical University Tianjin China
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138
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Galinsky R, Davidson JO, Lear CA, Bennet L, Green CR, Gunn AJ. Connexin hemichannel blockade improves survival of striatal GABA-ergic neurons after global cerebral ischaemia in term-equivalent fetal sheep. Sci Rep 2017; 7:6304. [PMID: 28740229 PMCID: PMC5524909 DOI: 10.1038/s41598-017-06683-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/15/2017] [Indexed: 11/17/2022] Open
Abstract
Basal ganglia injury at term remains a major cause of disability, such as cerebral palsy. In this study we tested the hypotheses that blockade of astrocytic connexin hemichannels with a mimetic peptide would improve survival of striatal phenotypic neurons after global cerebral ischaemia in term-equivalent fetal sheep, and that neuronal survival would be associated with electrophysiological recovery. Fetal sheep (0.85 gestation) were randomly assigned to receive a short or long (1 or 25 h) intracerebroventricular infusion of a mimetic peptide or vehicle, starting 90 minutes after 30 minutes of cerebral ischaemia. Sheep were killed 7 days after ischaemia. Cerebral ischaemia was associated with reduced numbers of calbindin-28k, calretinin, parvalbumin and GAD positive striatal neurons (P < 0.05 ischaemia + vehicle, n = 6 vs. sham ischaemia, n = 6) but not ChAT or nNOS positive neurons. Short infusion of peptide (n = 6) did not significantly improve survival of any striatal phenotype. Long infusion of peptide (n = 6) was associated with increased survival of calbindin-28k, calretinin, parvalbumin and GAD positive neurons (P < 0.05 vs. ischaemia + vehicle). Neurophysiological recovery was associated with improved survival of calbindin-28k, calretinin and parvalbumin positive striatal neurons (P < 0.05 for all). In conclusion, connexin hemichannel blockade after cerebral ischaemia in term-equivalent fetal sheep improves survival of striatal GABA-ergic neurons.
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Affiliation(s)
- Robert Galinsky
- Department of Physiology, The University of Auckland, Auckland, New Zealand.,The Ritchie Centre, Hudson Institute of Medical Research, Victoria, Australia
| | - Joanne O Davidson
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Christopher A Lear
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Department of Physiology, The University of Auckland, Auckland, New Zealand.
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139
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Yi C, Ezan P, Fernández P, Schmitt J, Sáez JC, Giaume C, Koulakoff A. Inhibition of glial hemichannels by boldine treatment reduces neuronal suffering in a murine model of Alzheimer's disease. Glia 2017; 65:1607-1625. [PMID: 28703353 DOI: 10.1002/glia.23182] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 05/04/2017] [Accepted: 05/30/2017] [Indexed: 01/06/2023]
Abstract
The contribution of reactive gliosis to the pathological phenotype of Alzheimer's disease (AD) opened the way for therapeutic strategies targeting glial cells instead of neurons. In such context, connexin hemichannels were proposed recently as potential targets since neuronal suffering is alleviated when connexin expression is genetically suppressed in astrocytes of a murine model of AD. Here, we show that boldine, an alkaloid from the boldo tree, inhibited hemichannel activity in astrocytes and microglia without affecting gap junctional communication in culture and acute hippocampal slices. Long-term oral administration of boldine in AD mice prevented the increase in glial hemichannel activity, astrocytic Ca2+ signal, ATP and glutamate release and alleviated hippocampal neuronal suffering. These findings highlight the important pathological role of hemichannels in AD mice. The neuroprotective effect of boldine treatment might provide the basis for future pharmacological strategies that target glial hemichannels to reduce neuronal damage in neurodegenerative diseases.
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Affiliation(s)
- Chenju Yi
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, 75005, France
| | - Pascal Ezan
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, 75005, France
| | - Paola Fernández
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro Interdisciplinario de Neurociencias de Valparaíso, Valparaíso, Chile
| | - Julien Schmitt
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neurosciences Paris Seine, Institut de Biologie Paris Seine (NPS-IBPS), Cerebellum Navigation and Memory team (CeZaMe), Paris, 75005, France
| | - Juan C Sáez
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro Interdisciplinario de Neurociencias de Valparaíso, Valparaíso, Chile
| | - Christian Giaume
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, 75005, France
| | - Annette Koulakoff
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, 75005, France
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140
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Boengler K, Bulic M, Schreckenberg R, Schlüter K, Schulz R. The gap junction modifier ZP1609 decreases cardiomyocyte hypercontracture following ischaemia/reperfusion independent from mitochondrial connexin 43. Br J Pharmacol 2017; 174:2060-2073. [PMID: 28369703 PMCID: PMC5466543 DOI: 10.1111/bph.13804] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 03/13/2017] [Accepted: 03/16/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE Dysregulation of gap junction-mediated cell coupling contributes to development of arrhythmias and myocardial damage after ischaemia/reperfusion (I/R). Connexin 43 (Cx43) is present at ventricular gap junctions and also in the mitochondria of cardiomyocytes. The dipeptide (2S, 4R)-1-(2-aminoacetyl)-4-benzamidopyrrolidine-2-carboxylic acid (ZP1609) has antiarrhythmic properties and reduces infarct size when given at reperfusion. However, it is unclear, whether ZP1609 targets Cx43-containing mitochondria and affects cardiomyocyte hypercontracture following I/R. EXPERIMENTAL APPROACH We studied the effects of ZP1609 on the function of murine sub-sarcolemmal mitochondria (SSM, containing Cx43) and interfibrillar mitochondria (IFM, lacking Cx43). Murine isolated cardiomyocytes were subjected to simulated I/R without and with ZP1609 (applied during I/R or at the onset of reperfusion only), and the number of cardiomyocytes undergoing hypercontracture was quantified. Biochemical pathways targeted by ZP1609 in cardiomyocytes were analysed. KEY RESULTS ZP1609 inhibited ADP-stimulated respiration and ATP production in SSM and IFM. ROS formation and calcium retention capacities in SSM and IFM were not affected by ZP1609, whereas potassium uptake was enhanced in IFM. The number of rod-shaped cardiomyocytes was increased by ZP1609 (10 μM) when administered either during I/R or reperfusion. ZP1609 altered the phosphorylation of proteins contributing to the protection against I/R injury. CONCLUSIONS AND IMPLICATIONS ZP1609 reduced mitochondrial respiration and ATP production, but enhanced potassium uptake of IFM. Additionally, ZP1609 reduced the extent of cardiomyocytes undergoing hypercontracture following I/R. The protective effect was independent of mitochondrial Cx43, as ZP1609 exerts its effects in Cx43-containing SSM and Cx43-lacking IFM.
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Affiliation(s)
- Kerstin Boengler
- Physiologisches InstitutJustus‐Liebig‐Universität GiessenGiessenGermany
| | - Marko Bulic
- Physiologisches InstitutJustus‐Liebig‐Universität GiessenGiessenGermany
| | | | | | - Rainer Schulz
- Physiologisches InstitutJustus‐Liebig‐Universität GiessenGiessenGermany
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141
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Rodríguez-Sinovas A, Ruiz-Meana M, Denuc A, García-Dorado D. Mitochondrial Cx43, an important component of cardiac preconditioning. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017. [PMID: 28642043 DOI: 10.1016/j.bbamem.2017.06.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Connexin 43 (Cx43) forms gap junction channels that are essential for the propagation of electrical depolarization in cardiomyocytes, but also with important roles in the pathophysiology of reperfusion injury. However, more recent studies have shown that Cx43 has also important functions independent from intercellular communication between adjacent cardiomyocytes. Some of these actions have been related to the presence of Cx43 in the mitochondria of these cells (mitoCx43). The functions of mitoCx43 have not been completely elucidated, but there is strong evidence indicating that mitoCx43 modulates mitochondrial respiration at respiratory complex I, production of radical oxygen species and ATP synthesis. These functions of mitoCx43 modulate mitochondrial and cellular tolerance to reperfusion after prolonged ischemia and are necessary for the cardioprotective effect of ischemic preconditioning. In the present review article we discuss available knowledge on these functions of mitoCx43 in relation to reperfusion injury, the molecular mechanisms involved and explore the possibility that mitoCx43 may constitute a new pharmacological target in patients with ST-segment elevation myocardial infarction (STEMI). This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Antonio Rodríguez-Sinovas
- Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Cardiovasculares (CIBERCV), Spain
| | - Marisol Ruiz-Meana
- Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Cardiovasculares (CIBERCV), Spain
| | - Amanda Denuc
- Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - David García-Dorado
- Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Cardiovasculares (CIBERCV), Spain.
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142
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DeLalio LJ, Isakson BE. ZP1609/danegaptide and mitochondrial connexin hemichannels: a harbinger for peptide drug design. Br J Pharmacol 2017; 174:2606-2607. [PMID: 28567717 DOI: 10.1111/bph.13891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/19/2017] [Accepted: 05/23/2017] [Indexed: 12/01/2022] Open
Abstract
LINKED ARTICLES This article is a Commentary on Boengler K, Bulic M, Schreckenberg R, Schlüter K-D, Schulz R (2017). The gap junction modifier ZP1609 decreases cardiomyocyte hypercontracture following ischaemia/reperfusion independent from mitochondrial connexin 43. Br J Pharmacol 174: 2060-2073. https://doi.org/10.1111/bph.13804.
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Affiliation(s)
- Leon J DeLalio
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA.,Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Brant E Isakson
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA.,Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA, USA
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143
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Epifantseva I, Shaw RM. Intracellular trafficking pathways of Cx43 gap junction channels. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:40-47. [PMID: 28576298 DOI: 10.1016/j.bbamem.2017.05.018] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/19/2017] [Accepted: 05/25/2017] [Indexed: 12/11/2022]
Abstract
Gap Junction (GJ) channels, including the most common Connexin 43 (Cx43), have fundamental roles in excitable tissues by facilitating rapid transmission of action potentials between adjacent cells. For instance, synchronization during each heartbeat is regulated by these ion channels at the cardiomyocyte cell-cell border. Cx43 protein has a short half-life, and rapid synthesis and timely delivery of those proteins to particular subdomains are crucial for the cellular organization of gap junctions and maintenance of intracellular coupling. Impairment in gap junction trafficking contributes to dangerous complications in diseased hearts such as the arrhythmias of sudden cardiac death. Of recent interest are the protein-protein interactions with the Cx43 carboxy-terminus. These interactions have significant impact on the full length Cx43 lifecycle and also contribute to trafficking of Cx43 as well as possibly other functions. We are learning that many of the known non-canonical roles of Cx43 can be attributed to the recently identified six endogenous Cx43 truncated isoforms which are produced by internal translation. In general, alternative translation is a new leading edge for proteome expansion and therapeutic drug development. This review highlights recent mechanisms identified in the trafficking of gap junction channels, involvement of other proteins contributing to the delivery of channels to the cell-cell border, and understanding of possible roles of the newly discovered alternatively translated isoforms in Cx43 biology. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Irina Epifantseva
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Robin M Shaw
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.; Department of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA..
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144
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Vicario N, Calabrese G, Zappalà A, Parenti C, Forte S, Graziano ACE, Vanella L, Pellitteri R, Cardile V, Parenti R. Inhibition of Cx43 mediates protective effects on hypoxic/reoxygenated human neuroblastoma cells. J Cell Mol Med 2017; 21:2563-2572. [PMID: 28488330 PMCID: PMC5618696 DOI: 10.1111/jcmm.13177] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 02/28/2017] [Indexed: 12/18/2022] Open
Abstract
Olfactory ensheathing cells (OECs), a special population of glial cells, are able to synthesise several trophic factors exerting a neuroprotective action and promoting growth and functional recovery in both in vitro and in vivo models. In the present work, we investigated the neuroprotective effects of OEC-conditioned medium (OEC-CM) on two different human neuron-like cell lines, SH-SY5Y and SK-N-SH (neuroblastoma cell lines), under normoxic and hypoxic conditions. In addition, we also focused our attention on the role of connexins (Cxs) in the neuroprotective processes. Our results confirmed OEC-CM mediated neuroprotection as shown by cell adherence, proliferation and cellular viability analyses. Reduced connexin 43 (Cx43) levels in OEC-CM compared to unconditioned cells in hypoxic conditions prompted us to investigate the role of Cx43-Gap junctions (GJs) and Cx43-hemichannels (HCs) in hypoxic/reoxygenation injury using carbenoxolone (non-selective GJ inhibitor), ioxynil octanoato (selective Cx43-GJ inhibitor) and Gap19 (selective Cx43-HC inhibitor). We found that Cx43-GJ and Cx43-HC inhibitors are able to protect SH-SY5Y and allow to these cultures to overcome the injury. Our findings support the hypothesis that both OEC-CM and the inhibition of Cx43-GJs and Cx43-HCs offer a neuroprotective effect by reducing Cx43-mediated cell-to-cell and cell-to-extracellular environment communications.
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Affiliation(s)
- Nunzio Vicario
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
| | - Giovanna Calabrese
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
| | - Agata Zappalà
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
| | - Carmela Parenti
- Department of Drug Sciences, University of Catania, Catania, Italy
| | | | | | - Luca Vanella
- Department of Drug Sciences, University of Catania, Catania, Italy
| | - Rosalia Pellitteri
- Institute Neurological Sciences, National Research Council, Catania, Italy
| | - Venera Cardile
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
| | - Rosalba Parenti
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
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145
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Zhang XF, Cui X. Connexin 43: Key roles in the skin. Biomed Rep 2017; 6:605-611. [PMID: 28584630 DOI: 10.3892/br.2017.903] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/17/2017] [Indexed: 12/26/2022] Open
Abstract
Gap junctions are tightly packed intercellular channels that serve a common purpose of allowing the intercellular exchange of small metabolites, second messengers and electrical signals. Connexins (Cxs) are gap junction proteins. Currently, 20 and 21 members of Cxs have been characterized in mice and humans, respectively. Connexin 43 (Cx43) is the most ubiquitously expressed type of Cx in the skin. It is produced by various different types of skin cell, such as keratinocytes, fibroblasts, endothelial and basal cells, melanocytes and dermal papilla cells. At present, more evidence indicates that Cx43 has an important role in skin repair and skin tumor development, as well as in skin cell invasion and metastasis. In this review, current knowledge regarding the regulation and function of Cx43 is summarized and the therapeutic potential of regulating Cx43 activity is discussed.
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Affiliation(s)
- Xiao-Fei Zhang
- Department of Biological Sciences and Biotechnology, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, Hubei 430070, P.R. China
| | - Xiaofeng Cui
- Department of Biological Sciences and Biotechnology, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, Hubei 430070, P.R. China
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146
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Hood AR, Ai X, Pogwizd SM. Regulation of cardiac gap junctions by protein phosphatases. J Mol Cell Cardiol 2017; 107:52-57. [PMID: 28478048 DOI: 10.1016/j.yjmcc.2017.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 04/13/2017] [Accepted: 05/02/2017] [Indexed: 01/16/2023]
Abstract
Sufficient connexin-mediated intercellular coupling is critical to maintain gap junctional communication for proper cardiac function. Alterations in connexin phosphorylation state, particularly dephosphorylation of connexin 43 (Cx43), may impact cell coupling and conduction in disease states. Cx43 dephosphorylation may be carried out by protein phosphatase activity. Here, we present an overview of the key phosphatases known to interact with Cx43 or modulators of Cx43, as well as some possible therapeutic targets to regulate phosphatase activity in the heart.
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Affiliation(s)
- Ashleigh R Hood
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Xun Ai
- Department of Biophysics and Physiology, Rush University, Chicago, IL, United States
| | - Steven M Pogwizd
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, United States; Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States.
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147
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Fauconnier J. Transfer of mitochondria after stroke: a new hope for cardioprotection coming from the brain? Cardiovasc Res 2017; 113:e10-e11. [PMID: 28453738 DOI: 10.1093/cvr/cvx057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jérémy Fauconnier
- UMR CNRS 9214, INSERM U1046, Université de Montpellier, CHU Montpellier, 371 Avenue du Doyen Gaston Giraud, 34295 Montpellier Cedex, France
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148
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Chen W, Guo Y, Yang W, Zheng P, Zeng J, Tong W. Involvement of autophagy in connexin 40 reduction in the late phase of traumatic brain injury in rats. Brain Res Bull 2017; 131:100-106. [PMID: 28373150 DOI: 10.1016/j.brainresbull.2017.03.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 03/17/2017] [Accepted: 03/29/2017] [Indexed: 10/19/2022]
Abstract
Brain trauma can activate an attenuation of connexin gap junction that is implicated in neuronal injury, but the underlying cellular mechanisms remain incompletely understood. Here, we aimed to study whether autophagy, a stress-response process for recycling of intracellular proteins and organelles, is involved in the reduction of connexin 40 (Cx40) during the late phase of traumatic brain injury (TBI). In a rat model of TBI induced by controlled cortical impact (CCI), we found that Cx40 protein in the brain started to decline at post-surgery day 2 and the decrease continued for up to day 6. Such a relatively late response of Cx40 following TBI was found to be coincident with the substantial induction of neuron degeneration and autophagy, elevated autophagic vacuole numbers, and induced LC3-II and p62 levels. At day 4 post-injury, the extent of co-localization between LC3 and Cx40 was greatly enhanced, and the reduction of Cx40 was rescued by the administration of an autophagy inhibitor chloroquine. Thus, autophagy stimulated in the injured brains may act as a suppressing mechanism to decrease gap junction protein Cx40 in the late phase of TBI.
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Affiliation(s)
- Wei Chen
- The People's Hospital of Pudong New Area, 490 South Chuanhuan Road, Chuansha New Town, Shanghai 201299, PR China
| | - Yijun Guo
- The People's Hospital of Pudong New Area, 490 South Chuanhuan Road, Chuansha New Town, Shanghai 201299, PR China
| | - Wenjin Yang
- The People's Hospital of Pudong New Area, 490 South Chuanhuan Road, Chuansha New Town, Shanghai 201299, PR China
| | - Ping Zheng
- The People's Hospital of Pudong New Area, 490 South Chuanhuan Road, Chuansha New Town, Shanghai 201299, PR China
| | - Jinsong Zeng
- The People's Hospital of Pudong New Area, 490 South Chuanhuan Road, Chuansha New Town, Shanghai 201299, PR China
| | - Wusong Tong
- The People's Hospital of Pudong New Area, 490 South Chuanhuan Road, Chuansha New Town, Shanghai 201299, PR China.
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149
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Spatio-temporal regulation of connexin43 phosphorylation and gap junction dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:83-90. [PMID: 28414037 DOI: 10.1016/j.bbamem.2017.04.008] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/05/2017] [Accepted: 04/11/2017] [Indexed: 01/23/2023]
Abstract
Gap junctions are specialized membrane domains containing tens to thousands of intercellular channels. These channels permit exchange of small molecules (<1000Da) including ions, amino acids, nucleotides, metabolites and secondary messengers (e.g., calcium, glucose, cAMP, cGMP, IP3) between cells. The common reductionist view of these structures is that they are composed entirely of integral membrane proteins encoded by the 21 member connexin human gene family. However, it is clear that the normal physiological function of this structure requires interaction and regulation by a variety of proteins, especially kinases. Phosphorylation is capable of directly modulating connexin channel function but the most dramatic effects on gap junction activity occur via the organization of the gap junction structures themselves. This is a direct result of the short half-life of the primary gap junction protein, connexin, which requires them to be constantly assembled, remodeled and turned over. The biological consequences of this remodeling are well illustrated during cardiac ischemia, a process wherein gap junctions are disassembled and remodeled resulting in arrhythmia and ultimately heart failure. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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150
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Mitochondrial Cx43 hemichannels contribute to mitochondrial calcium entry and cell death in the heart. Basic Res Cardiol 2017; 112:27. [PMID: 28364353 DOI: 10.1007/s00395-017-0618-1] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
Abstract
Mitochondrial connexin 43 (Cx43) plays a key role in cardiac cytoprotection caused by repeated exposure to short periods of non-lethal ischemia/reperfusion, a condition known as ischemic preconditioning. Cx43 also forms calcium (Ca2+)-permeable hemichannels that may potentially lead to mitochondrial Ca2+ overload and cell death. Here, we studied the role of Cx43 in facilitating mitochondrial Ca2+ entry and investigated its downstream consequences. To that purpose, we used various connexin-targeting peptides interacting with extracellular (Gap26) and intracellular (Gap19, RRNYRRNY) Cx43 domains, and tested their effect on mitochondrial dye- and Ca2+-uptake, electrophysiological properties of plasmalemmal and mitochondrial Cx43 channels, and cell injury/cell death. Our results in isolated mice cardiac subsarcolemmal mitochondria indicate that Cx43 forms hemichannels that contribute to Ca2+ entry and may trigger permeability transition and cell injury/death. RRNYRRNY displayed the strongest effects in all assays and inhibited plasma membrane as well as mitochondrial Cx43 hemichannels. RRNYRRNY also strongly reduced the infarct size in ex vivo cardiac ischemia-reperfusion studies. These results indicate that Cx43 contributes to mitochondrial Ca2+ homeostasis and is involved in triggering cell injury/death pathways that can be inhibited by RRNYRRNY peptide.
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