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Golino M, Harding D, Del Buono MG, Fanti S, Mohiddin S, Toldo S, Smyth J, Sanna T, Marelli-Berg F, Abbate A. Innate and adaptive immunity in acute myocarditis. Int J Cardiol 2024; 404:131901. [PMID: 38403204 DOI: 10.1016/j.ijcard.2024.131901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/12/2024] [Accepted: 02/21/2024] [Indexed: 02/27/2024]
Abstract
Acute myocarditis is an acute inflammatory cardiomyopathy associated with cardiac damage triggered by a virus or a pathological immune activation. It may present with a wide range of clinical presentations, ranging from mild symptoms to severe forms like fulminant myocarditis, characterized by hemodynamic compromise and cardiogenic shock. The immune system plays a central role in the pathogenesis of myocarditis. In fact, while its function is primarily protective, aberrant responses can be detrimental. In this context, both innate and adaptive immunity play pivotal roles; notably, the innate system offers a non-specific and immediate defense, while the adaptive provides specialized protection with immunological memory. However, dysregulation in these systems can misidentify cardiac tissue, triggering autoimmune reactions and possibly leading to significant cardiac tissue damage. This review highlights the importance of innate and adaptive immune responses in the progression and treatment of acute myocarditis.
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Affiliation(s)
- Michele Golino
- Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, United States of America; Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Daniel Harding
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Marco Giuseppe Del Buono
- Department of Cardiovascular Medicine, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Silvia Fanti
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Saidi Mohiddin
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, London, United Kingdom; Barts Heart Centre, London, United Kingdom
| | - Stefano Toldo
- Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, United States of America
| | - James Smyth
- Fralin Biomedical Research Institute at Virginia Tech Carillion, Roanoke, VA, United States of America; Virginia Tech Carilion School of Medicine, Roanoke, VA, United States of America; Department of Biological Sciences, College of Science, Virginia Tech, Blacksburg, VA, United States of America
| | - Tommaso Sanna
- Department of Cardiovascular Medicine, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Federica Marelli-Berg
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, London, United Kingdom.
| | - Antonio Abbate
- Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, United States of America.
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2
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Liao L, Wang T, Zhang L, Wei Y, Fan X. Protective Mechanisms of SGLTi in Ischemic Heart Disease. J Cardiovasc Transl Res 2024:10.1007/s12265-024-10513-x. [PMID: 38767796 DOI: 10.1007/s12265-024-10513-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 04/11/2024] [Indexed: 05/22/2024]
Abstract
Ischemic heart disease (IHD) is a common clinical cardiovascular disease with high morbidity and mortality. Sodium glucose cotransporter protein inhibitor (SGLTi) is a novel hypoglycemic drug. To date, both clinical trials and animal experiments have shown that SGLTi play a protective role in IHD, including myocardial infarction (MI) and ischemia/reperfusion (I/R). The protective effects may be involved in mechanisms of energy metabolic conversion, anti-inflammation, anti-fibrosis, ionic homeostasis improvement, immune cell development, angiogenesis and functional regulation, gut microbiota regulation, and epicardial lipids. Thus, this review summarizes the above mechanisms and aims to provide theoretical evidence for therapeutic strategies for IHD.
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Affiliation(s)
- Lei Liao
- Department of Cardiology, the Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
| | - Tong Wang
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, 646000, Sichuan, China
| | - Lu Zhang
- Department of Cardiology, the Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
| | - Yan Wei
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, 646000, Sichuan, China.
| | - Xinrong Fan
- Department of Cardiology, the Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China.
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, 646000, Sichuan, China.
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3
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Padget RL, Zeitz MJ, Blair GA, Wu X, North MD, Tanenbaum MT, Stanley KE, Phillips CM, King DR, Lamouille S, Gourdie RG, Hoeker GS, Swanger SA, Poelzing S, Smyth JW. Acute Adenoviral Infection Elicits an Arrhythmogenic Substrate Prior to Myocarditis. Circ Res 2024; 134:892-912. [PMID: 38415360 PMCID: PMC11003857 DOI: 10.1161/circresaha.122.322437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/12/2024] [Indexed: 02/29/2024]
Abstract
BACKGROUND Viral cardiac infection represents a significant clinical challenge encompassing several etiological agents, disease stages, complex presentation, and a resulting lack of mechanistic understanding. Myocarditis is a major cause of sudden cardiac death in young adults, where current knowledge in the field is dominated by later disease phases and pathological immune responses. However, little is known regarding how infection can acutely induce an arrhythmogenic substrate before significant immune responses. Adenovirus is a leading cause of myocarditis, but due to species specificity, models of infection are lacking, and it is not understood how adenoviral infection may underlie sudden cardiac arrest. Mouse adenovirus type-3 was previously reported as cardiotropic, yet it has not been utilized to understand the mechanisms of cardiac infection and pathology. METHODS We have developed mouse adenovirus type-3 infection as a model to investigate acute cardiac infection and molecular alterations to the infected heart before an appreciable immune response or gross cardiomyopathy. RESULTS Optical mapping of infected hearts exposes decreases in conduction velocity concomitant with increased Cx43Ser368 phosphorylation, a residue known to regulate gap junction function. Hearts from animals harboring a phospho-null mutation at Cx43Ser368 are protected against mouse adenovirus type-3-induced conduction velocity slowing. Additional to gap junction alterations, patch clamping of mouse adenovirus type-3-infected adult mouse ventricular cardiomyocytes reveals prolonged action potential duration as a result of decreased IK1 and IKs current density. Turning to human systems, we find human adenovirus type-5 increases phosphorylation of Cx43Ser368 and disrupts synchrony in human induced pluripotent stem cell-derived cardiomyocytes, indicating common mechanisms with our mouse whole heart and adult cardiomyocyte data. CONCLUSIONS Together, these findings demonstrate that adenoviral infection creates an arrhythmogenic substrate through direct targeting of gap junction and ion channel function in the heart. Such alterations are known to precipitate arrhythmias and likely contribute to sudden cardiac death in acutely infected patients.
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Affiliation(s)
- Rachel L. Padget
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Michael J. Zeitz
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Grace A. Blair
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Xiaobo Wu
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Michael D. North
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
| | | | - Kari E. Stanley
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Chelsea M. Phillips
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - D. Ryan King
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Samy Lamouille
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Robert G. Gourdie
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - Gregory S. Hoeker
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Sharon A. Swanger
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA
| | - Steven Poelzing
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - James W. Smyth
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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4
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Pun R, Cavanaugh AM, Aldrich E, Tran O, Rudd JC, Hansen LA, North BJ. PKCμ promotes keratinocyte cell migration through Cx43 phosphorylation-mediated suppression of intercellular communication. iScience 2024; 27:109033. [PMID: 38375220 PMCID: PMC10875573 DOI: 10.1016/j.isci.2024.109033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 12/18/2023] [Accepted: 01/23/2024] [Indexed: 02/21/2024] Open
Abstract
Downregulation of intercellular communication through suppression of gap junctional conductance is necessary during wound healing. Connexin 43 (Cx43), a prominent gap junction protein in skin, is downregulated following wounding to restrict communication between keratinocytes. Previous studies found that PKCμ, a novel PKC isozyme, regulates efficient cutaneous wound healing. However, the molecular mechanism by which PKCμ regulates wound healing remains unknown. We have identified that PKCμ suppresses intercellular communication and enhances cell migration in an in vitro wound healing model by regulating Cx43 containing gap junctions. PKCμ can directly interact with and phosphorylate Cx43 at S368, which leads to Cx43 internalization and downregulation. Finally, utilizing phosphomimetic and non-phosphorylatable S368 substitutions and gap junction inhibitors, we confirmed that PKCμ regulates intercellular communication and in vitro wound healing by controlling Cx43-S368 phosphorylation. These results define PKCμ as a critical regulator of Cx43 phosphorylation to control cell migration and wound healing in keratinocytes.
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Affiliation(s)
- Renju Pun
- Biomedical Sciences Department, School of Medicine, Creighton University, Omaha, NE 68178, USA
| | - Ann M. Cavanaugh
- Department of Biology, College of Arts and Sciences, Creighton University, Omaha, NE 68178, USA
| | - Emily Aldrich
- Biomedical Sciences Department, School of Medicine, Creighton University, Omaha, NE 68178, USA
| | - Olivia Tran
- Biomedical Sciences Department, School of Medicine, Creighton University, Omaha, NE 68178, USA
| | - Justin C. Rudd
- Biomedical Sciences Department, School of Medicine, Creighton University, Omaha, NE 68178, USA
| | - Laura A. Hansen
- Biomedical Sciences Department, School of Medicine, Creighton University, Omaha, NE 68178, USA
| | - Brian J. North
- Biomedical Sciences Department, School of Medicine, Creighton University, Omaha, NE 68178, USA
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5
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Al-attar R, Jargstorf J, Romagnuolo R, Jouni M, Alibhai FJ, Lampe PD, Solan JL, Laflamme MA. Casein Kinase 1 Phosphomimetic Mutations Negatively Impact Connexin-43 Gap Junctions in Human Pluripotent Stem Cell-Derived Cardiomyocytes. Biomolecules 2024; 14:61. [PMID: 38254663 PMCID: PMC10813327 DOI: 10.3390/biom14010061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/14/2023] [Accepted: 12/25/2023] [Indexed: 01/24/2024] Open
Abstract
The transplantation of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) has shown promise in preclinical models of myocardial infarction, but graft myocardium exhibits incomplete host-graft electromechanical integration and a propensity for pro-arrhythmic behavior. Perhaps contributing to this situation, hPSC-CM grafts show low expression of connexin 43 (Cx43), the major gap junction (GJ) protein, in ventricular myocardia. We hypothesized that Cx43 expression and function could be rescued by engineering Cx43 in hPSC-CMs with a series of phosphatase-resistant mutations at three casein kinase 1 phosphorylation sites (Cx43-S3E) that have been previously reported to stabilize Cx43 GJs and reduce arrhythmias in transgenic mice. However, contrary to our predictions, transgenic Cx43-S3E hPSC-CMs exhibited reduced Cx43 expression relative to wild-type cells, both at baseline and following ischemic challenge. Cx43-S3E hPSC-CMs showed correspondingly slower conduction velocities, increased automaticity, and differential expression of other connexin isoforms and various genes involved in cardiac excitation-contraction coupling. Cx43-S3E hPSC-CMs also had phosphorylation marks associated with Cx43 GJ internalization, a finding that may account for their impaired GJ localization. Taken collectively, our data indicate that the Cx43-S3E mutation behaves differently in hPSC-CMs than in adult mouse ventricular myocytes and that multiple biological factors likely need to be addressed synchronously to ensure proper Cx43 expression, localization, and function.
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Affiliation(s)
- Rasha Al-attar
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Joseph Jargstorf
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Rocco Romagnuolo
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Mariam Jouni
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Faisal J. Alibhai
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Paul D. Lampe
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; (P.D.L.); (J.L.S.)
| | - Joell L. Solan
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; (P.D.L.); (J.L.S.)
| | - Michael A. Laflamme
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON M5G 1L7, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5G 1L7, Canada
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6
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Fernandez-Flores A, Varela-Vazquez A, Mayan MD, Fonseca E. Connexin 43 in Dermatofibroma and Dermatofibrosarcoma Protuberans: Diagnostic, Pathogenic, and Therapeutic Implications. Am J Dermatopathol 2023; 45:812-815. [PMID: 37982464 DOI: 10.1097/dad.0000000000002562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
ABSTRACT Connexins play a crucial role in the formation of gap junctions that connect cells to each other, as well as cells to the surrounding environment. In recent years, connexin 43 has been extensively studied in various human tumors. In this study, we conducted an immunohistochemical analysis to evaluate the expression of connexin in 16 dermatofibromas (DFs) and 13 dermatofibrosarcoma protuberans (DFSP). Connexin was diffusely expressed in the cytoplasm of all DFs with moderate or strong intensity, whereas all DFSPs showed negative staining. In addition to its diagnostic implications, the loss of Cx43 may elucidate the invasive capacity of DFSP and offer a potential avenue for future therapeutic interventions.
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Affiliation(s)
- Angel Fernandez-Flores
- Department of Cellular Pathology, Hospital El Bierzo, Ponferrada, Spain
- Department of Cellular Pathology, Hospital de la Reina, Ponferrada, Spain
| | - Adrian Varela-Vazquez
- Department of Research, Institute for Biomedical Research of A Coruña (INIBIC), University of A Coruña (UDC), A Coruña, Spain; and
| | - Maria D Mayan
- Department of Research, Institute for Biomedical Research of A Coruña (INIBIC), University of A Coruña (UDC), A Coruña, Spain; and
| | - Eduardo Fonseca
- Department of Research, Institute for Biomedical Research of A Coruña (INIBIC), University of A Coruña (UDC), A Coruña, Spain; and
- Department of Dermatology, Universitary Hospital of A Coruña, A Coruña, Spain
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7
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Madeira D, Domingues J, Lopes CR, Canas PM, Cunha RA, Agostinho P. Modification of astrocytic Cx43 hemichannel activity in animal models of AD: modulation by adenosine A 2A receptors. Cell Mol Life Sci 2023; 80:340. [PMID: 37898985 PMCID: PMC10613596 DOI: 10.1007/s00018-023-04983-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 09/07/2023] [Accepted: 09/26/2023] [Indexed: 10/31/2023]
Abstract
Increasing evidence implicates astrocytic dysfunction in Alzheimer's disease (AD), a neurodegenerative disorder characterised by progressive cognitive loss. The accumulation of amyloid-β (Aβ) plaques is a histopathological hallmark of AD and associated with increased astrocyte reactivity. In APP/PS1 mice modelling established AD (9 months), we now show an altered astrocytic morphology and enhanced activity of astrocytic hemichannels, mainly composed by connexin 43 (Cx43). Hemichannel activity in hippocampal astrocytes is also increased in two models of early AD: (1) mice with intracerebroventricular (icv) administration of Aβ1-42, and (2) hippocampal slices superfused with Aβ1-42 peptides. In hippocampal gliosomes of APP/PS1 mice, Cx43 levels were increased, whereas mice administered icv with Aβ1-42 only displayed increased Cx43 phosphorylation levels. This suggests that hemichannel activity might be differentially modulated throughout AD progression. Additionally, we tested if adenosine A2A receptor (A2AR) blockade reversed alterations of astrocytic hemichannel activity and found that the pharmacological blockade or genetic silencing (global and astrocytic) of A2AR prevented Aβ-induced hemichannel dysregulation in hippocampal slices, although A2AR genetic silencing increased the activity of astroglial hemichannels in control conditions. In primary cultures of astrocytes, A2AR-related protective effect was shown to occur through a protein kinase C (PKC) pathway. Our results indicate that the dysfunction of hemichannel activity in hippocampal astrocytes is an early event in AD, which is modulated by A2AR.
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Affiliation(s)
- Daniela Madeira
- Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Rua Larga, Polo I FMUC, First Floor, 3004-504, Coimbra, Portugal
| | - Joana Domingues
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Rua Larga, Polo I FMUC, First Floor, 3004-504, Coimbra, Portugal
| | - Cátia R Lopes
- Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Rua Larga, Polo I FMUC, First Floor, 3004-504, Coimbra, Portugal
| | - Paula M Canas
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Rua Larga, Polo I FMUC, First Floor, 3004-504, Coimbra, Portugal
| | - Rodrigo A Cunha
- Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Rua Larga, Polo I FMUC, First Floor, 3004-504, Coimbra, Portugal
| | - Paula Agostinho
- Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal.
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Rua Larga, Polo I FMUC, First Floor, 3004-504, Coimbra, Portugal.
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8
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Adams WP, Raisch TB, Zhao Y, Davalos R, Barrett S, King DR, Bain CB, Colucci-Chang K, Blair GA, Hanlon A, Lozano A, Veeraraghavan R, Wan X, Deschenes I, Smyth JW, Hoeker GS, Gourdie RG, Poelzing S. Extracellular Perinexal Separation Is a Principal Determinant of Cardiac Conduction. Circ Res 2023; 133:658-673. [PMID: 37681314 PMCID: PMC10561697 DOI: 10.1161/circresaha.123.322567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 08/29/2023] [Indexed: 09/09/2023]
Abstract
BACKGROUND Cardiac conduction is understood to occur through gap junctions. Recent evidence supports ephaptic coupling as another mechanism of electrical communication in the heart. Conduction via gap junctions predicts a direct relationship between conduction velocity (CV) and bulk extracellular resistance. By contrast, ephaptic theory is premised on the existence of a biphasic relationship between CV and the volume of specialized extracellular clefts within intercalated discs such as the perinexus. Our objective was to determine the relationship between ventricular CV and structural changes to micro- and nanoscale extracellular spaces. METHODS Conduction and Cx43 (connexin43) protein expression were quantified from optically mapped guinea pig whole-heart preparations perfused with the osmotic agents albumin, mannitol, dextran 70 kDa, or dextran 2 MDa. Peak sodium current was quantified in isolated guinea pig ventricular myocytes. Extracellular resistance was quantified by impedance spectroscopy. Intercellular communication was assessed in a heterologous expression system with fluorescence recovery after photobleaching. Perinexal width was quantified from transmission electron micrographs. RESULTS CV primarily in the transverse direction of propagation was significantly reduced by mannitol and increased by albumin and both dextrans. The combination of albumin and dextran 70 kDa decreased CV relative to albumin alone. Extracellular resistance was reduced by mannitol, unchanged by albumin, and increased by both dextrans. Cx43 expression and conductance and peak sodium currents were not significantly altered by the osmotic agents. In response to osmotic agents, perinexal width, in order of narrowest to widest, was albumin with dextran 70 kDa; albumin or dextran 2 MDa; dextran 70 kDa or no osmotic agent, and mannitol. When compared in the same order, CV was biphasically related to perinexal width. CONCLUSIONS Cardiac conduction does not correlate with extracellular resistance but is biphasically related to perinexal separation, providing evidence that the relationship between CV and extracellular volume is determined by ephaptic mechanisms under conditions of normal gap junctional coupling.
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Affiliation(s)
- William P. Adams
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Tristan B. Raisch
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Yajun Zhao
- School of Biomedical Engineering and Sciences, Virginia Tech
| | - Rafael Davalos
- School of Biomedical Engineering and Sciences, Virginia Tech
| | | | - D. Ryan King
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Chandra B. Bain
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
| | - Katrina Colucci-Chang
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- School of Biomedical Engineering and Sciences, Virginia Tech
| | - Grace A. Blair
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Alexandra Hanlon
- Virginia Tech Center for Biostatistics and Health Data Science, Roanoke, Virginia
| | - Alicia Lozano
- Virginia Tech Center for Biostatistics and Health Data Science, Roanoke, Virginia
| | - Rengasayee Veeraraghavan
- Department of Biomedical Engineering, College of Engineering, The Ohio State University
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center
| | - Xiaoping Wan
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center
| | - Isabelle Deschenes
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center
| | - James W. Smyth
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Department of Biological Sciences, College of Science, Virginia Tech
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia
| | - Gregory S. Hoeker
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
| | - Robert G. Gourdie
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- School of Biomedical Engineering and Sciences, Virginia Tech
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia
| | - Steven Poelzing
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
- School of Biomedical Engineering and Sciences, Virginia Tech
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia
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9
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Zheng L, Spagnol G, Gandhi DR, Sharma K, Kumar V, Patel KP, Sorgen PL. Inhibition of Pyk2 Improves Cx43 Intercalated Disc Localization, Infarct Size, and Cardiac Function in Rats With Heart Failure. Circ Heart Fail 2023; 16:e010294. [PMID: 37465947 PMCID: PMC10524803 DOI: 10.1161/circheartfailure.122.010294] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 05/12/2023] [Indexed: 07/20/2023]
Abstract
BACKGROUND Heart failure causes changes in Cx43 (Connexin43) regulation that are associated with arrhythmic heart disease. Pyk2 (proline-rich tyrosine kinase 2) is activated in cardiomyopathies and phosphorylates Cx43 to decrease intercellular communication. This study was designed to determine if Pyk2 inhibition improves cardiac function in a myocardial infarction (MI)-induced heart failure model in rats. METHODS MI (ligation of left anterior descending artery) rats were treated with the Pyk2 inhibitor PF4618433. Hemodynamic and structural parameters were monitored in Sham (n=5), MI-vehicle (n=5), and MI-PF4618433 (n=8) groups. Heart tissues were collected after 6 weeks to assess Pyk2 and Cx43 protein level and localization. RESULTS PF4618433 produced no observed adverse effects and inhibited ventricular Pyk2. PF4618433 reduced the MI infarct size from 34% to 17% (P=0.007). PF4618433 improved stroke volume (P=0.031) and cardiac output (P=0.009) in comparison to MI-vehicle with values similar to the Sham group. PF4618433 also led to an increase in the ejection fraction (P=0.002) and fractional shortening (P=0.006) when compared with the MI-vehicle (32% and 35% improvement, respectively) yet were lower in comparison with the Sham group. Pyk2 inhibition decreased Cx43 tyrosine phosphorylation (P=0.043) and maintained Cx43 at the intercalated disc in the distal ventricle 6 weeks post-MI. CONCLUSIONS Unlike other attempts to decrease Cx43 remodeling after MI-induced heart failure, inhibition of Pyk2 activity maintained Cx43 at the intercalated disc. This may have aided in the reduced infarct size (acute time frame) and improved cardiac function (chronic time frame). Additionally, we provide evidence that Pyk2 is activated following MI in human left ventricle, implicating a novel potential target for therapy in patients with heart failure.
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Affiliation(s)
- Li Zheng
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Gaelle Spagnol
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Devashri R. Gandhi
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kanika Sharma
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Vikas Kumar
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kaushik P. Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Paul L. Sorgen
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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10
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Nielsen MS, van Opbergen CJM, van Veen TAB, Delmar M. The intercalated disc: a unique organelle for electromechanical synchrony in cardiomyocytes. Physiol Rev 2023; 103:2271-2319. [PMID: 36731030 PMCID: PMC10191137 DOI: 10.1152/physrev.00021.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
The intercalated disc (ID) is a highly specialized structure that connects cardiomyocytes via mechanical and electrical junctions. Although described in some detail by light microscopy in the 19th century, it was in 1966 that electron microscopy images showed that the ID represented apposing cell borders and provided detailed insight into the complex ID nanostructure. Since then, much has been learned about the ID and its molecular composition, and it has become evident that a large number of proteins, not all of them involved in direct cell-to-cell coupling via mechanical or gap junctions, reside at the ID. Furthermore, an increasing number of functional interactions between ID components are emerging, leading to the concept that the ID is not the sum of isolated molecular silos but an interacting molecular complex, an "organelle" where components work in concert to bring about electrical and mechanical synchrony. The aim of the present review is to give a short historical account of the ID's discovery and an updated overview of its composition and organization, followed by a discussion of the physiological implications of the ID architecture and the local intermolecular interactions. The latter will focus on both the importance of normal conduction of cardiac action potentials as well as the impact on the pathophysiology of arrhythmias.
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Affiliation(s)
- Morten S Nielsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chantal J M van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
| | - Toon A B van Veen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
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11
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Zhang M, Wang ZZ, Chen NH. Connexin 43 Phosphorylation: Implications in Multiple Diseases. Molecules 2023; 28:4914. [PMID: 37446576 DOI: 10.3390/molecules28134914] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
Connexin 43 (Cx43) is most widely distributed in mammals, especially in the cardiovascular and nervous systems. Its phosphorylation state has been found to be regulated by the action of more than ten kinases and phosphatases, including mitogen-activated protein kinase/extracellular signaling and regulating kinase signaling. In addition, the phosphorylation status of different phosphorylation sites affects its own synthesis and assembly and the function of the gap junctions (GJs) to varying degrees. The phosphorylation of Cx43 can affect the permeability, electrical conductivity, and gating properties of GJs, thereby having various effects on intercellular communication and affecting physiological or pathological processes in vitro and in vivo. Therefore, clarifying the relationship between Cx43 phosphorylation and specific disease processes will help us better understand the disease. Based on the above clinical and preclinical findings, we present in this review the functional significance of Cx43 phosphorylation in multiple diseases and discuss the potential of Cx43 as a drug target in Cx43-related disease pathophysiology, with an emphasis on the importance of connexin 43 as an emerging therapeutic target in cardiac and neuroprotection.
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Affiliation(s)
- Meng Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Science 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 Science and Peking Union Medical College, Beijing 100050, China
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100050, China
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12
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Li Y, Chang HM, Sung YW, Zhu H, Leung PCK, Sun YP. Betacellulin regulates gap junction intercellular communication by inducing the phosphorylation of connexin 43 in human granulosa-lutein cells. J Ovarian Res 2023; 16:103. [PMID: 37231448 DOI: 10.1186/s13048-023-01185-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 05/06/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND The gap junction protein, connexin 43 (Cx43) is highly expressed in human granulosa-lutein (hGL) cells. The phosphorylation of certain amino acid residues in the Cx43 protein has been shown to be related to a decline in gap junction intercellular communication (GJIC), which subsequently affects oocyte meiotic resumption. As a member of the epidermal growth factor (EGF) family, betacellulin (BTC) mediates luteinizing hormone (LH)-induced oocyte maturation and cumulus cell expansion in mammalian follicles. Whether BTC can regulate Cx43 phosphorylation, which further reduces Cx43-coupled GJIC activity in hGL cells remains to be determined. METHODS Immortalized human granulosa cells (SVOG cells) and primary human granulosa-lutein cells obtained from women undergoing in vitro fertilization in an academic research center were used as the study models. The expression levels of Cx43 and phosphorylated Cx43 were examined following cell incubation with BTC at different time points. Several kinase inhibitors (sotrastaurin, AG1478, and U0126) and small interfering RNAs targeting EGF receptor (EGFR) and receptor tyrosine-protein kinase 4 (ErbB4) were used to verify the specificity of the effects and to investigate the molecular mechanisms. Real-time-quantitative PCR and western blot analysis were used to detect the specific mRNA and protein levels, respectively. GJIC between SVOG cells were evaluated using a scrape loading and dye transfer assay. Results were analyzed by one-way analysis of variance. RESULTS The results showed that BTC induced the rapid phosphorylation of Cx43 at serine368 without altering the expression of Cx43 in primary and immortalized hGL cells. Additionally, using a dual inhibition approach (kinase inhibitors and siRNA-based expression knockdown), we demonstrated that this effect was mainly mediated by the EGFR but not the ErbB4 receptor. Furthermore, using a protein kinase C (PKC) kinase assay and a scrape-loading and dye transfer assay, we revealed that PKC signaling is the downstream signaling pathway that mediates the increase in Cx43 phosphorylation and subsequent decrease in GJIC activity in response to BTC treatment in hGL cells. CONCLUSIONS BTC promptly induced the phosphorylation of connexin 43 at Ser368, leading to decreased GJIC activity in hGL cells. The BTC-induced cellular activities were most likely driven by the EGFR-mediated PKC-dependent signaling pathway. Our findings shed light on the detailed molecular mechanisms by which BTC regulates the process of oocyte meiotic resumption.
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Affiliation(s)
- Yuxi Li
- Center for Reproductive Medicine, The First Affiliated Hospital of Zhengzhou University, 40, Daxue Road, Zhengzhou, 450052, Henan, China
- Department of Obstetrics and Gynecology, BC Children's Hospital Research Institute, University of British Columbia, Room 317, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Henan Key Laboratory of Reproduction and Genetics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Henan Provincial Obstetrical and Gynecological Diseases (Reproductive Medicine) Clinical Research Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Hsun-Ming Chang
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Wen Sung
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, China Medical University Hospital, Taichung, Taiwan
| | - Hua Zhu
- Department of Obstetrics and Gynecology, BC Children's Hospital Research Institute, University of British Columbia, Room 317, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
| | - Peter C K Leung
- Department of Obstetrics and Gynecology, BC Children's Hospital Research Institute, University of British Columbia, Room 317, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada.
| | - Ying-Pu Sun
- Center for Reproductive Medicine, The First Affiliated Hospital of Zhengzhou University, 40, Daxue Road, Zhengzhou, 450052, Henan, China.
- Henan Key Laboratory of Reproduction and Genetics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
- Henan Provincial Obstetrical and Gynecological Diseases (Reproductive Medicine) Clinical Research Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
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13
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Leybaert L, De Smet MA, Lissoni A, Allewaert R, Roderick HL, Bultynck G, Delmar M, Sipido KR, Witschas K. Connexin hemichannels as candidate targets for cardioprotective and anti-arrhythmic treatments. J Clin Invest 2023; 133:168117. [PMID: 36919695 PMCID: PMC10014111 DOI: 10.1172/jci168117] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023] Open
Abstract
Connexins are crucial cardiac proteins that form hemichannels and gap junctions. Gap junctions are responsible for the propagation of electrical and chemical signals between myocardial cells and cells of the specialized conduction system in order to synchronize the cardiac cycle and steer cardiac pump function. Gap junctions are normally open, while hemichannels are closed, but pathological circumstances may close gap junctions and open hemichannels, thereby perturbing cardiac function and homeostasis. Current evidence demonstrates an emerging role of hemichannels in myocardial ischemia and arrhythmia, and tools are now available to selectively inhibit hemichannels without inhibiting gap junctions as well as to stimulate hemichannel incorporation into gap junctions. We review available experimental evidence for hemichannel contributions to cellular pro-arrhythmic events in ventricular and atrial cardiomyocytes, and link these to insights at the level of molecular control of connexin-43-based hemichannel opening. We conclude that a double-edged approach of both preventing hemichannel opening and preserving gap junctional function will be key for further research and development of new connexin-based experimental approaches for treating heart disease.
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Affiliation(s)
- Luc Leybaert
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Maarten Aj De Smet
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Alessio Lissoni
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Rosalie Allewaert
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - H Llewelyn Roderick
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, and
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Mario Delmar
- Leon H. Charney Division of Cardiology, School of Medicine, New York University, New York, USA
| | - Karin R Sipido
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, and
| | - Katja Witschas
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
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14
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Jabr RI, Salvage SC, Hatch FS, Fry CH. Calcineurin-dependent regulation of gap junction conductance and connexin phosphorylation in guinea pig left atrium. Pflugers Arch 2023; 475:583-593. [PMID: 36917272 PMCID: PMC10105670 DOI: 10.1007/s00424-023-02798-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 02/18/2023] [Accepted: 02/20/2023] [Indexed: 03/16/2023]
Abstract
Atrial fibrillation (AF) occurs from disordered atrial action potential conduction and is associated with reduced gap junction electrical conductance (Gj). The Ca2+ and calmodulin-dependent phosphatase, calcineurin, reduces Gj in ventricular myocardium via a protein phosphatase-1 (PP1)-dependent pathway culminating in phosphorylation of serine368 on connexin43 (pSer368-Cx43). However, characterisation of corresponding pathways in left atrial myocardium, which have a more complex connexin subtype profile, is undefined and was the aim of this study. Gj was measured in guinea-pig left atrium from the frequency-dependent variation of intracellular impedance; intracellular [Ca2+], ([Ca2+]i) in low-Na solution was measured by Fura-2 fluorescence. Phosphorylation of guinea-pig Ser368-Cx43 residues was measured by Western blot; Cx40 was immunoprecipitated and probed for serine/threonine residue phosphorylation. Low-Na solution reversibly reduced Gj, in turn attenuated or prevented by calcineurin inhibitors cyclosporin-A or CAIP, respectively. Moreover, Ser368-Cx43 phosphorylation in low-Na solution was also prevented by CAIP. Changes were partially prevented by fostreicin (FST), a protein phosphatase-2A (PP2A) inhibitor; but not by tautomycin, a PP1 inhibitor. Serine/threonine residues on Cx40 were also phosphorylated in low-Na solution; prevented by CAIP and attenuated by FST. Reduced Gj with raised [Ca2+]i is paralleled by a changed Cx43/Cx40 phosphorylation status; changes mediated by calcineurin and PP2A-dependent pathways, but not PP1. The pharmacological profile underlying changes to guinea-pig atrial gap junction electrical conductance with raised intracellular [Ca2+]i is fundamentally different from that in ventricular myocardium. This provides a targeted drug model whereby atrial and ventricular myocardium can be selectively targeted to correct conduction defects.
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Affiliation(s)
- R I Jabr
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - S C Salvage
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - F S Hatch
- Department of Biochemistry and Physiology, Surrey University, Guildford, UK
| | - C H Fry
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.
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15
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β3 adrenergic receptor activation modulates connexin 43 activity to relax human myometrium. Cell Signal 2023; 106:110640. [PMID: 36841274 PMCID: PMC10134909 DOI: 10.1016/j.cellsig.2023.110640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/27/2023] [Accepted: 02/21/2023] [Indexed: 02/27/2023]
Abstract
Preterm labor, delivery prior to 37 completed weeks of gestation, is the leading cause of infant morbidity and mortality. β3 adrenergic receptor protein expression is increased in the myometrium during pregnancy, and the agonist, mirabegron, relaxes the myometrium making the β3 adrenergic receptor a potential therapeutic target in PTL. β3 adrenergic receptor has been shown to activate the tyrosine kinase, Src, which can down regulate connexin 43, a contractile associated protein which promotes the formation of gap junctions that create an electrical syncytium. We hypothesize that mirabegron downregulates connexin 43, imparting quiescence effects on the myometrium. Employing contractile studies, we demonstrate that Src is involved in the mirabegron-induced relaxation of contracting pregnant human myometrial tissue strips. Western blot analysis demonstrates that Src kinase expression is decreased in both preterm and term laboring myometrial tissue. Imaging revealed that mirabegron stimulation of the β3 adrenergic receptor phosphorylates tyrosine at position Y265 on connexin 43 in pregnant human uterine myocytes. Western blot analysis and immunofluorescent imaging indicate that mirabegron decreases the expression of connexin 43 and mediates relaxation over a 24-h exposure period, suggesting that mirabegron has long lasting quiescent effects on the human myometrium. The relationship between the β3 adrenergic receptor and down regulation of the contractile associated protein connexin 43 through activation of Src kinase suggests that mirabegron may be useful in combination tocolysis.
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16
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Zhao GL, Zhou H, Guo YH, Zhong SM, Zhou H, Li F, Lei B, Wang Z, Miao Y. Modulation of Rac1/PAK1/connexin43-mediated ATP release from astrocytes contributes to retinal ganglion cell survival in experimental glaucoma. Glia 2023; 71:1502-1521. [PMID: 36794533 DOI: 10.1002/glia.24354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/17/2023]
Abstract
Connexin43 (Cx43) is a major gap junction protein in glial cells. Mutations have been found in the gap-junction alpha 1 gene encoding Cx43 in glaucomatous human retinas, suggestive of the involvement of Cx43 in the pathogenesis of glaucoma. However, how Cx43 is involved in glaucoma is still unknown. We showed that increased intraocular pressure in a glaucoma mouse model of chronic ocular hypertension (COH) downregulated Cx43, which was mainly expressed in retinal astrocytes. Astrocytes in the optic nerve head where they gather and wrap the axons (optic nerve) of retinal ganglion cells (RGCs) were activated earlier than neurons in COH retinas and the alterations in astrocytes plasticity in the optic nerve caused a reduction in Cx43 expression. A time course showed that reductions of Cx43 expression were correlated with the activation of Rac1, a member of the Rho family. Co-immunoprecipitation assays showed that active Rac1, or the downstream signaling effector PAK1, negatively regulated Cx43 expression, Cx43 hemichannel opening and astrocyte activation. Pharmacological inhibition of Rac1 stimulated Cx43 hemichannel opening and ATP release, and astrocytes were identified to be one of the main sources of ATP. Furthermore, conditional knockout of Rac1 in astrocytes enhanced Cx43 expression and ATP release, and promoted RGC survival by upregulating the adenosine A3 receptor in RGCs. Our study provides new insight into the relationship between Cx43 and glaucoma, and suggests that regulating the interaction between astrocytes and RGCs via the Rac1/PAK1/Cx43/ATP pathway may be used as part of a therapeutic strategy for managing glaucoma.
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Affiliation(s)
- Guo-Li Zhao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Hong Zhou
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yun-Hui Guo
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Shu-Min Zhong
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Han Zhou
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Fang Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Bo Lei
- Institute of Neuroscience and Third Affiliated Hospital, Henan Provincial People's Hospital, Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Zhongfeng Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yanying Miao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
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17
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Jiang H, Zhang Y, Wang ZZ, Chen NH. Connexin 43: An Interface Connecting Neuroinflammation to Depression. Molecules 2023; 28:molecules28041820. [PMID: 36838809 PMCID: PMC9961786 DOI: 10.3390/molecules28041820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023] Open
Abstract
Major depressive disorder (MDD) is a leading chronic mental illness worldwide, characterized by anhedonia, pessimism and even suicidal thoughts. Connexin 43 (Cx43), mainly distributed in astrocytes of the brain, is by far the most widely and ubiquitously expressed connexin in almost all vital organs. Cx43 forms gap junction channels in the brain, which mediate energy exchange and effectively maintain physiological homeostasis. Increasing evidence suggests the crucial role of Cx43 in the pathogenesis of MDD. Neuroinflammation is one of the most common pathological features of the central nervous system dysfunctions. Inflammatory factors are abnormally elevated in patients with depression and are closely related to nearly all links of depression. After activating the inflammatory pathway in the brain, the release and uptake of glutamate and adenosine triphosphate, through Cx43 in the synaptic cleft, would be affected. In this review, we have summarized the association between Cx43 and neuroinflammation, the cornerstones linking inflammation and depression, and Cx43 abnormalities in depression. We also discuss the significant association of Cx43 in inflammation and depression, which will help to explore new antidepressant drug targets.
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Affiliation(s)
- Hong Jiang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical, Science and Peking Union Medical College, Beijing 100050, China
| | - Yi Zhang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 102488, 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, Science and Peking Union Medical College, Beijing 100050, China
- Correspondence: (Z.-Z.W.); (N.-H.C.); Tel.: +86-10-6316-5182 (Z.-Z.W.); +86-10-63165177 (N.-H.C.)
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical, Science and Peking Union Medical College, Beijing 100050, China
- Correspondence: (Z.-Z.W.); (N.-H.C.); Tel.: +86-10-6316-5182 (Z.-Z.W.); +86-10-63165177 (N.-H.C.)
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18
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El-Hajjar L, Saliba J, Karam M, Shaito A, El Hajj H, El-Sabban M. Ubiquitin-Related Modifier 1 (URM-1) Modulates Cx43 in Breast Cancer Cell Lines. Int J Mol Sci 2023; 24:ijms24032958. [PMID: 36769280 PMCID: PMC9917400 DOI: 10.3390/ijms24032958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/23/2022] [Accepted: 12/28/2022] [Indexed: 02/05/2023] Open
Abstract
Gap-junction-forming connexins are exquisitely regulated by post-translational modifications (PTMs). In particular, the PTM of connexin 43 (Cx43), a tumor suppressor protein, regulates its turnover and activity. Here, we investigated the interaction of Cx43 with the ubiquitin-related modifier 1 (URM-1) protein and its impact on tumor progression in two breast cancer cell lines, highly metastatic triple-negative MDA-MB-231 and luminal breast cancer MCF-7 cell lines. To evaluate the subsequent modulation of Cx43 levels, URM-1 was downregulated in these cells. The transcriptional levels of epithelial-to-mesenchymal transition (EMT) markers and the metastatic phenotype were assessed. We demonstrated that Cx43 co-localizes and interacts with URM-1, and URMylated Cx43 was accentuated upon cellular stress. The significant upregulation of small ubiquitin-like modifier-1 (SUMO-1) was also observed. In cells with downregulated URM-1, Cx43 expression significantly decreased, and SUMOylation by SUMO-1 was affected. The concomitant expression of EMT markers increased, leading to increased proliferation, migration, and invasion potential. Inversely, the upregulation of URM-1 increased Cx43 expression and reversed EMT-induced processes, underpinning a role for this PTM in the observed phenotypes. This study proposes that the URMylation of Cx43 in breast cancer cells regulates its tumor suppression properties and contributes to breast cancer cell malignancy.
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Affiliation(s)
- Layal El-Hajjar
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut P.O. Box 11-0236, Lebanon
| | - Jessica Saliba
- Department of Biology, Faculty of Sciences, Lebanese University, Beirut P.O. Box 90656, Lebanon
- Department of Public Health, Faculty of Health Sciences, University of Balamand, Beirut P.O. Box 100, Lebanon
| | - Mario Karam
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut P.O. Box 11-0236, Lebanon
| | - Abdullah Shaito
- Biomedical Research Center, Qatar University Doha, Doha P.O. Box 2713, Qatar
| | - Hiba El Hajj
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut P.O. Box 11-0236, Lebanon
| | - Marwan El-Sabban
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut P.O. Box 11-0236, Lebanon
- Correspondence: ; Tel.: +961-(1)-350000 (ext. 4765)
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19
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Welcome MO, Dogo D, Nikos E Mastorakis. Cellular mechanisms and molecular pathways linking bitter taste receptor signalling to cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases. Inflammopharmacology 2023; 31:89-117. [PMID: 36471190 PMCID: PMC9734786 DOI: 10.1007/s10787-022-01086-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/11/2022] [Indexed: 12/12/2022]
Abstract
Heart diseases and related complications constitute a leading cause of death and socioeconomic threat worldwide. Despite intense efforts and research on the pathogenetic mechanisms of these diseases, the underlying cellular and molecular mechanisms are yet to be completely understood. Several lines of evidence indicate a critical role of inflammatory and oxidative stress responses in the development and progression of heart diseases. Nevertheless, the molecular machinery that drives cardiac inflammation and oxidative stress is not completely known. Recent data suggest an important role of cardiac bitter taste receptors (TAS2Rs) in the pathogenetic mechanism of heart diseases. Independent groups of researchers have demonstrated a central role of TAS2Rs in mediating inflammatory, oxidative stress responses, autophagy, impulse generation/propagation and contractile activities in the heart, suggesting that dysfunctional TAS2R signalling may predispose to cardiac inflammatory and oxidative stress disorders, characterised by contractile dysfunction and arrhythmia. Moreover, cardiac TAS2Rs act as gateway surveillance units that monitor and detect toxigenic or pathogenic molecules, including microbial components, and initiate responses that ultimately culminate in protection of the host against the aggression. Unfortunately, however, the molecular mechanisms that link TAS2R sensing of the cardiac milieu to inflammatory and oxidative stress responses are not clearly known. Therefore, we sought to review the possible role of TAS2R signalling in the pathophysiology of cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases. Potential therapeutic significance of targeting TAS2R or its downstream signalling molecules in cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction is also discussed.
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Affiliation(s)
- Menizibeya O Welcome
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Nile University of Nigeria, Plot 681 Cadastral Zone, C-00 Research and Institution Area, Jabi Airport Road Bypass, FCT, Abuja, Nigeria.
| | - Dilli Dogo
- Department of Surgery, Faculty of Clinical Sciences, College of Health Sciences, Nile University of Nigeria, Abuja, Nigeria
| | - Nikos E Mastorakis
- Technical University of Sofia, Klement Ohridksi 8, Sofia, 1000, Bulgaria
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20
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Maneechote C, Kerdphoo S, Jaiwongkam T, Chattipakorn SC, Chattipakorn N. Chronic Pharmacological Modulation of Mitochondrial Dynamics Alleviates Prediabetes-Induced Myocardial Ischemia-Reperfusion Injury by Preventing Mitochondrial Dysfunction and Programmed Apoptosis. Cardiovasc Drugs Ther 2023; 37:89-105. [PMID: 34515894 DOI: 10.1007/s10557-021-07250-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/25/2021] [Indexed: 01/14/2023]
Abstract
PURPOSE There is an increasing body of evidence to show that impairment in mitochondrial dynamics including excessive fission and insufficient fusion has been observed in the pre-diabetic condition. In pre-diabetic rats with cardiac ischemia-reperfusion (I/R) injury, acute treatment with a mitochondria fission inhibitor (Mdivi-1) and a fusion promoter (M1) showed cardioprotection. However, the potential preventive effects of chronic Mdivi-1 and M1 treatment in a pre-diabetic model of cardiac I/R have never been elucidated. METHODS Male Wistar rats (n = 40) were fed with a high-fat diet (HFD) for 12 weeks to induce prediabetes. Then, all pre-diabetic rats received the following treatments daily via intraperitoneal injection for 2 weeks: (1) HFDV (Vehicle, 0.1% DMSO); (2) HFMdivi1 (Mdivi-1 1.2 mg/kg); (3) HFM1 (M1 2 mg/kg); and (4) HFCom (Mdivi-1 + M1). At the end of treatment protocols, all rats underwent 30 min of coronary artery ligation followed by reperfusion for 120 min. RESULTS Chronic Mdivi-1, M1, and the combined treatment showed markedly improved cardiac mitochondrial function and dynamic control, leading to a decrease in cardiac arrhythmias, myocardial cell death, and infarct size (49%, 42%, and 51% reduction for HFMdivi1, HFM1, and HFCom, respectively vs HFDV). All of these treatments improved cardiac function following cardiac I/R injury in pre-diabetic rats. CONCLUSION Chronic inhibition of mitochondrial fission and promotion of fusion exerted cardioprevention in prediabetes with cardiac I/R injury through the relief of cardiac mitochondrial dysfunction and dynamic alterations, and reduction in myocardial infarction, thus improving cardiac function.
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Affiliation(s)
- Chayodom Maneechote
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Sasiwan Kerdphoo
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Thidarat Jaiwongkam
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Siriporn C Chattipakorn
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Nipon Chattipakorn
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand.
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand.
- Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand.
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21
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Shahid K, Khan K, Badshah Y, Mahmood Ashraf N, Hamid A, Trembley JH, Shabbir M, Afsar T, Almajwal A, Abusharha A, Razak S. Pathogenicity of PKCγ Genetic Variants-Possible Function as a Non-Invasive Diagnostic Biomarker in Ovarian Cancer. Genes (Basel) 2023; 14:236. [PMID: 36672978 PMCID: PMC9858858 DOI: 10.3390/genes14010236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/06/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
Ovarian cancer has the highest mortality rate among gynecologic malignancies, owing to its misdiagnosis or late diagnosis. Identification of its genetic determinants could improve disease outcomes. Conventional Protein Kinase C-γ (PKCγ) dysregulation is reported in several cancers. Similarly, its variant rs1331262028 is also reported to have an association with hepatocellular carcinoma. Therefore, the aim of the present study was to analyze the variant rs1331262028 association with ovarian cancer and to determine its impact on PKCγ's protein interactions. Association of variation was determined through genotyping PCR (cohort size:100). Protein-protein docking and molecular dynamic simulation were carried out to study the variant impact of PKCγ interactions. The study outcome indicated the positive association of variant rs1331262028 with ovarian cancer and its clinicopathological features. Molecular dynamics simulation depicted the potential influence of variation on PKCγ molecular signaling. Hence, this study provided the foundations for assessing variant rs1331262028 as a potential prognostic marker for ovarian cancer. Through further validation, it can be applied at the clinical level.
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Affiliation(s)
- Kanza Shahid
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad 44010, Pakistan
| | - Khushbukhat Khan
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad 44010, Pakistan
| | - Yasmin Badshah
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad 44010, Pakistan
| | - Naeem Mahmood Ashraf
- School of Biochemistry and Biotechnology, University of the Punjab, Lahore 54590, Pakistan
| | - Arslan Hamid
- LIMES Institute (AG-Netea), University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany
| | - Janeen H. Trembley
- Minneapolis VA Health Care System Research Service, Minneapolis, MN 55417, USA
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Maria Shabbir
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad 44010, Pakistan
| | - Tayyaba Afsar
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia
| | - Ali Almajwal
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia
| | - Ali Abusharha
- Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia
| | - Suhail Razak
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia
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22
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Pun R, Kim MH, North BJ. Role of Connexin 43 phosphorylation on Serine-368 by PKC in cardiac function and disease. Front Cardiovasc Med 2023; 9:1080131. [PMID: 36712244 PMCID: PMC9877470 DOI: 10.3389/fcvm.2022.1080131] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/19/2022] [Indexed: 01/13/2023] Open
Abstract
Intercellular communication mediated by gap junction channels and hemichannels composed of Connexin 43 (Cx43) is vital for the propagation of electrical impulses through cardiomyocytes. The carboxyl terminal tail of Cx43 undergoes various post-translational modifications including phosphorylation of its Serine-368 (S368) residue. Protein Kinase C isozymes directly phosphorylate S368 to alter Cx43 function and stability through inducing conformational changes affecting channel permeability or promoting internalization and degradation to reduce intercellular communication between cardiomyocytes. Recent studies have implicated this PKC/Cx43-pS368 circuit in several cardiac-associated diseases. In this review, we describe the molecular and cellular basis of PKC-mediated Cx43 phosphorylation and discuss the implications of Cx43 S368 phosphorylation in the context of various cardiac diseases, such as cardiomyopathy, as well as the therapeutic potential of targeting this pathway.
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Affiliation(s)
- Renju Pun
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States
| | - Michael H. Kim
- CHI Health Heart Institute, School of Medicine, Creighton University, Omaha, NE, United States
| | - Brian J. North
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States,*Correspondence: Brian J. North,
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23
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Zeitz MJ, Smyth JW. Gap Junctions and Ageing. Subcell Biochem 2023; 102:113-137. [PMID: 36600132 DOI: 10.1007/978-3-031-21410-3_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Gap junctions, comprising connexin proteins, create conduits directly coupling the cytoplasms of adjacent cells. Expressed in essentially all tissues, dynamic gap junction structures enable the exchange of small molecules including ions and second messengers, and are central to maintenance of homeostasis and synchronized excitability. With such diverse and critical roles throughout the body, it is unsurprising that alterations to gap junction and/or connexin expression and function underlie a broad array of age-related pathologies. From neurological dysfunction to cardiac arrhythmia and bone loss, it is hard to identify a human disease state that does not involve reduced, or in some cases inappropriate, intercellular communication to affect organ function. With a complex life cycle encompassing several key regulatory steps, pathological gap junction remodeling during ageing can arise from alterations in gene expression, translation, intracellular trafficking, and posttranslational modification of connexins. Connexin proteins are now known to "moonlight" and perform a variety of non-junctional functions in the cell, independent of gap junctions. Furthermore, connexin "hemichannels" on the cell surface can communicate with the extracellular space without ever coupling to an adjacent cell to form a gap junction channel. This chapter will focus primarily on gap junctions in ageing, but such non-junctional connexin functions will be referred to where appropriate and the full spectrum of connexin biology should be noted as potentially causative/contributing to some findings in connexin knockout animals, for example.
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Affiliation(s)
- Michael J Zeitz
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA.,FBRI Center for Vascular and Heart Research, Roanoke, VA, USA
| | - James W Smyth
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA. .,FBRI Center for Vascular and Heart Research, Roanoke, VA, USA. .,Department of Biological Sciences, College of Science, Virginia Tech, Blacksburg, VA, USA. .,Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA.
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24
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Sedovy MW, Leng X, Leaf MR, Iqbal F, Payne LB, Chappell JC, Johnstone SR. Connexin 43 across the Vasculature: Gap Junctions and Beyond. J Vasc Res 2022; 60:101-113. [PMID: 36513042 PMCID: PMC11073551 DOI: 10.1159/000527469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/26/2022] [Indexed: 12/15/2022] Open
Abstract
Connexin 43 (Cx43) is essential to the function of the vasculature. Cx43 proteins form gap junctions that allow for the exchange of ions and molecules between vascular cells to facilitate cell-to-cell signaling and coordinate vasomotor activity. Cx43 also has intracellular signaling functions that influence vascular cell proliferation and migration. Cx43 is expressed in all vascular cell types, although its expression and function vary by vessel size and location. This includes expression in vascular smooth muscle cells (vSMC), endothelial cells (EC), and pericytes. Cx43 is thought to coordinate homocellular signaling within EC and vSMC. Cx43 gap junctions also function as conduits between different cell types (heterocellular signaling), between EC and vSMC at the myoendothelial junction, and between pericyte and EC in capillaries. Alterations in Cx43 expression, localization, and post-translational modification have been identified in vascular disease states, including atherosclerosis, hypertension, and diabetes. In this review, we discuss the current understanding of Cx43 localization and function in healthy and diseased blood vessels across all vascular beds.
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Affiliation(s)
- Meghan W. Sedovy
- The Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, 4 Riverside Circle, Roanoke, VA, USA
- Translational Biology, Medicine, And Health Graduate Program, Virginia Tech, Blacksburg, VA, USA
| | - Xinyan Leng
- The Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, 4 Riverside Circle, Roanoke, VA, USA
| | - Melissa R. Leaf
- The Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, 4 Riverside Circle, Roanoke, VA, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
| | - Farwah Iqbal
- The Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, 4 Riverside Circle, Roanoke, VA, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
| | - Laura Beth Payne
- The Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, 4 Riverside Circle, Roanoke, VA, USA
| | - John C. Chappell
- The Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, 4 Riverside Circle, Roanoke, VA, USA
| | - Scott R. Johnstone
- The Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, 4 Riverside Circle, Roanoke, VA, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
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25
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Kwek XY, Hall AR, Lim WW, Katwadi K, Soong PL, Grishina E, Lin KH, Crespo-Avilan G, Yap EP, Ismail NI, Chinda K, Chung YY, Wei H, Shim W, Montaigne D, Tinker A, Ong SB, Hausenloy DJ. Role of cardiac mitofusins in cardiac conduction following simulated ischemia-reperfusion. Sci Rep 2022; 12:21049. [PMID: 36473917 PMCID: PMC9727036 DOI: 10.1038/s41598-022-25625-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction induced by acute cardiac ischemia-reperfusion (IR), may increase susceptibility to arrhythmias by perturbing energetics, oxidative stress production and calcium homeostasis. Although changes in mitochondrial morphology are known to impact on mitochondrial function, their role in cardiac arrhythmogenesis is not known. To assess action potential duration (APD) in cardiomyocytes from the Mitofusins-1/2 (Mfn1/Mfn2)-double-knockout (Mfn-DKO) compared to wild-type (WT) mice, optical-electrophysiology was conducted. To measure conduction velocity (CV) in atrial and ventricular tissue from the Mfn-DKO and WT mice, at both baseline and following simulated acute IR, multi-electrode array (MEA) was employed. Intracellular localization of connexin-43 (Cx43) at baseline was evaluated by immunohistochemistry, while Cx-43 phosphorylation was assessed by Western-blotting. Mfn-DKO cardiomyocytes demonstrated an increased APD. At baseline, CV was significantly lower in the left ventricle of the Mfn-DKO mice. CV decreased with simulated-ischemia and returned to baseline levels during simulated-reperfusion in WT but not in atria of Mfn-DKO mice. Mfn-DKO hearts displayed increased Cx43 lateralization, although phosphorylation of Cx43 at Ser-368 did not differ. In summary, Mfn-DKO mice have increased APD and reduced CV at baseline and impaired alterations in CV following cardiac IR. These findings were associated with increased Cx43 lateralization, suggesting that the mitofusins may impact on post-MI cardiac-arrhythmogenesis.
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Affiliation(s)
- Xiu-Yi Kwek
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore
| | - Andrew R. Hall
- grid.83440.3b0000000121901201The Hatter Cardiovascular Institute, Institute of Cardiovascular Science, University College London, London, UK
| | - Wei-Wen Lim
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore ,grid.428397.30000 0004 0385 0924Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Khairunnisa Katwadi
- grid.428397.30000 0004 0385 0924Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Poh Loong Soong
- grid.4280.e0000 0001 2180 6431Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore ,grid.4280.e0000 0001 2180 6431Cardiovascular Translational Program, Cardiovascular Research Institute (CVRI), National University of Singapore, Singapore, Singapore ,grid.412106.00000 0004 0621 9599Department of Medicine, National University Hospital of Singapore (NUHS), Singapore, Singapore ,Ternion Biosciences, Singapore, Singapore
| | | | | | - Gustavo Crespo-Avilan
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore ,grid.428397.30000 0004 0385 0924Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore ,grid.8664.c0000 0001 2165 8627Department of Biochemistry, Medical Faculty, Justus Liebig-University, Giessen, Germany
| | - En Ping Yap
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore
| | - Nur Izzah Ismail
- grid.10784.3a0000 0004 1937 0482Centre for Cardiovascular Genomics and Medicine (CCGM), Lui Che Woo Institute of Innovative Medicine, Chinese University of Hong Kong (CUHK), Hong Kong, SAR China ,grid.10784.3a0000 0004 1937 0482Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong (CUHK), Hong Kong, SAR China ,Hong Kong Hub of Paediatric Excellence (HK HOPE), Hong Kong Children’s Hospital (HKCH), Kowloon Bay, Hong Kong, SAR China
| | - Kroekkiat Chinda
- grid.412029.c0000 0000 9211 2704Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand ,grid.412029.c0000 0000 9211 2704Integrative Cardiovascular Research Unit, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Ying Ying Chung
- grid.428397.30000 0004 0385 0924Centre for Vision Research, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Heming Wei
- grid.414963.d0000 0000 8958 3388Research Laboratory, KK Women’s & Children’s Hospital, Singapore, Singapore
| | - Winston Shim
- grid.486188.b0000 0004 1790 4399Health and Social Sciences Cluster, Singapore Institute of Technology, Singapore, Singapore
| | - David Montaigne
- grid.503422.20000 0001 2242 6780Inserm, CHU Lille, Institut Pasteur Lille, U1011-European Genomic Institute for Diabetes (EGID), University of Lille, 59000 Lille, France
| | - Andrew Tinker
- grid.4868.20000 0001 2171 1133Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | - Sang-Bing Ong
- grid.10784.3a0000 0004 1937 0482Centre for Cardiovascular Genomics and Medicine (CCGM), Lui Che Woo Institute of Innovative Medicine, Chinese University of Hong Kong (CUHK), Hong Kong, SAR China ,grid.10784.3a0000 0004 1937 0482Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong (CUHK), Hong Kong, SAR China ,Hong Kong Hub of Paediatric Excellence (HK HOPE), Hong Kong Children’s Hospital (HKCH), Kowloon Bay, Hong Kong, SAR China ,grid.9227.e0000000119573309Joint Laboratory of Bioresources and Molecular Research of Common Diseases, Kunming Institute of Zoology-The Chinese University of Hong Kong (KIZ-CUHK), Chinese Academy of Sciences, Kunming, Yunnan China ,grid.10784.3a0000 0004 1937 0482Shenzhen Research Institute (SZRI), Chinese University of Hong Kong (CUHK), Shenzhen, China
| | - Derek J. Hausenloy
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore ,grid.83440.3b0000000121901201The Hatter Cardiovascular Institute, Institute of Cardiovascular Science, University College London, London, UK ,grid.428397.30000 0004 0385 0924Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore ,grid.4280.e0000 0001 2180 6431Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore
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Dellaqua TT, Vígaro RA, Janini LCZ, Dal Canto M, Renzini MM, Lodde V, Luciano AM, Buratini J. Neuregulin 1 (NRG1) modulates oocyte nuclear maturation during IVM and improves post-IVF embryo development. Theriogenology 2022; 195:209-216. [DOI: 10.1016/j.theriogenology.2022.10.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/31/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
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Gao J, Xue G, Zhan G, Wang X, Li J, Yang X, Xia Y. Benefits of SGLT2 inhibitors in arrhythmias. Front Cardiovasc Med 2022; 9:1011429. [PMID: 36337862 PMCID: PMC9631490 DOI: 10.3389/fcvm.2022.1011429] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 10/04/2022] [Indexed: 09/25/2023] Open
Abstract
Some studies have shown that sodium-glucose cotransporter (SGLT) 2 inhibitors can definitively attenuate the occurrence of cardiovascular diseases such as heart failure (HF), dilated cardiomyopathy (DCM), and myocardial infarction. With the development of research, SGLT2 inhibitors can also reduce the risk of arrhythmias. So in this review, how SGLT2 inhibitors play a role in reducing the risk of arrhythmia from the perspective of electrical remodeling and structural remodeling are explored and then the possible mechanisms are discussed. Specifically, we focus on the role of SGLT2 inhibitors in Na+ and Ca2 + homeostasis and the transients of Na+ and Ca2 +, which could affect electrical remodeling and then lead to arrythmia. We also discuss the protective role of SGLT2 inhibitors in structural remodeling from the perspective of fibrosis, inflammation, oxidative stress, and apoptosis. Ultimately, it is clear that SGLT2 inhibitors have significant benefits on cardiovascular diseases such as HF, myocardial hypertrophy and myocardial infarction. It can be expected that SGLT2 inhibitors can reduce the risk of arrhythmia.
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Affiliation(s)
| | | | | | | | | | | | - Yunlong Xia
- Department of Cardiology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
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28
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Zhang NN, Zhang Y, Wang ZZ, Chen NH. Connexin 43: insights into candidate pathological mechanisms of depression and its implications in antidepressant therapy. Acta Pharmacol Sin 2022; 43:2448-2461. [PMID: 35145238 PMCID: PMC9525669 DOI: 10.1038/s41401-022-00861-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 01/06/2022] [Indexed: 11/09/2022] Open
Abstract
Major depressive disorder (MDD), a chronic and recurrent disease characterized by anhedonia, pessimism or even suicidal thought, remains a major chronic mental concern worldwide. Connexin 43 (Cx43) is the most abundant connexin expressed in astrocytes and forms the gap junction channels (GJCs) between astrocytes, the most abundant and functional glial cells in the brain. Astrocytes regulate neurons' synaptic strength and function by expressing receptors and regulating various neurotransmitters. Astrocyte dysfunction causes synaptic abnormalities, which are related to various mood disorders, e.g., depression. Increasing evidence suggests a crucial role of Cx43 in the pathogenesis of depression. Depression down-regulates Cx43 expression in humans and rats, and dysfunction of Cx43 also induces depressive behaviors in rats and mice. Recently Cx43 has received considerable critical attention and is highly implicated in the onset of depression. However, the pathological mechanisms of depression-like behavior associated with Cx43 still remain ambiguous. In this review we summarize the recent progress regarding the underlying mechanisms of Cx43 in the etiology of depression-like behaviors including gliotransmission, metabolic disorders, and neuroinflammation. We also discuss the effects of antidepressants (monoamine antidepressants and ketamine) on Cx43. The clarity of the candidate pathological mechanisms of depression-like behaviors associated with Cx43 and its potential pharmacological roles for antidepressants will benefit the exploration of a novel antidepressant target.
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Affiliation(s)
- Ning-Ning Zhang
- 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
| | - Yi Zhang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 102488, 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.
| | - 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.
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Effect of WenXin KeLi on Improvement of Arrhythmia after Myocardial Infarction by Intervening PI3K-AKT-mTOR Autophagy Pathway. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:2022970. [PMID: 36212955 PMCID: PMC9536921 DOI: 10.1155/2022/2022970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/12/2022] [Accepted: 09/10/2022] [Indexed: 11/17/2022]
Abstract
Background Myocardial infarction (MI) is an acute and serious cardiovascular disease. Arrhythmia after MI can lead to sudden cardiac death, which seriously affects the survival outcome of patients. WenXin KeLi is a Chinese patent medicine for the treatment of arrhythmia in a clinic, which can significantly improve symptoms of palpitation and play an important role in reducing the risk of arrhythmia after MI. In this study, we aimed to explore the pharmacological mechanism of WenXin KeLi in protecting the heart. Methods The MI model was established by ligating the left coronary artery and the ventricular fibrillation threshold (VFT) was measured by electrical stimulation. The expression of connexin43 (CX43) and autophagy-related protein were measured by Western Blot, and correlation analysis was conducted to study the relationship between cardiac autophagy, CX43, and arrhythmia in rats after MI. The effects of WenXin KeLi on arrhythmia, cardiac structure, and function in MI rats were respectively observed by electrical stimulation, cardiac gross section, Masson staining, and cardiac ultrasound. The effects of WenXin KeLi on the expression of phosphoinositide 3 kinase-protein kinase B-mammalian targets of rapamycin (PI3K-AKT-mTOR) autophagy pathway and CX43 were observed by Western Blot. Results After 4 weeks of MI, the VFT in the model group was significantly reduced, the expression levels of yeast ATG6 homolog (Beclin1), microtubule-associated protein 1A/1B-light chain 3 (LC3II/LC3I), and p-CX43 (S368) significantly increased, the expression of sequestosome-1(P62) and CX43 significantly decreased. LC3II/LC3I and Beclin1 expression were significantly negatively correlated with the VFT, and the expression of P62 and CX43 were significantly positively correlated with the VFT. LC3II/LC3I and Beclin1 expression were negatively correlated with CX43 expression, while P62 expression was positively correlated with CX43 expression. WenXin KeLi could significantly increase the VFT, reduce the deposition of collagen fibers, and increase the index levels of the left ventricular end-diastolic anterior wall (LVEDAW), interventricular septum end-diastolic (IVSED), left ventricular end-systolic anterior wall (LVESAW), interventricular septum end-systolic (IVSES), left ventricular end-diastolic posterior wall (LVEDPW), left ventricular end-systolic posterior wall (LVESPW), left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), and reduce the index levels of the left ventricular end-diastolic dimension (LVEDD), left ventricular end-systolic dimension (LVESD), left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV). WenXin KeLi could increase the expression of CX43, P62, AKT, p-PI3K, p-AKT (308), p-AKT (473), and p-mTOR and decrease the expression of LC3II/LC3I and Beclin1. Conclusion WenXin KeLi can activate the PI3K-AKT-mTOR signaling pathway, improve cardiac autophagy and Cx43 expression in rats after MI, reduce the risk of arrhythmia after MI, and play a cardioprotective role.
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Quentin V, Singh M, Nguyen LS. A review of potential mechanisms and uses of SGLT2 inhibitors in ischemia-reperfusion phenomena. World J Diabetes 2022; 13:683-695. [PMID: 36188147 PMCID: PMC9521445 DOI: 10.4239/wjd.v13.i9.683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/13/2022] [Accepted: 08/16/2022] [Indexed: 02/05/2023] Open
Abstract
Recently added to the therapeutic arsenal against chronic heart failure as a first intention drug, the antidiabetic drug-class sodium-glucose cotransporter-2 inhibitors (SGLT2i) showed efficacy in decreasing overall mortality, hospitalization, and sudden death in patients of this very population, in whom chronic or acute ischemia count among the first cause. Remarkably, this benefit was observed independently from diabetic status, and benefited both preserved and altered ventricular ejection fraction. This feature, observed in several large randomized controlled trials, suggests additional effects from SGLT2i beyond isolated glycemia control. Indeed, both in-vitro and animal models suggest that inhibiting the Na+/H+ exchanger (NHE) may be key to preventing ischemia/ reperfusion injuries, and by extension may hold a similar role in ischemic damage control and ischemic preconditioning. Yet, several other mechanisms may be explored which may help better target those who may benefit most from SGLT2i molecules. Because of a large therapeutic margin with few adverse events, ease of prescription and potential pharmacological efficacity, SGLT2i could be candidate for wider indications. In this review, we aim to summarize all evidence which link SGLT2i and ischemia/reperfusion injuries modulation, by first listing known mechanisms, including metabolic switch, prevention of lethal arrythmias and others, which portend the latter, and second, hypothesize how the former may interact with these mechanisms.
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Affiliation(s)
- Victor Quentin
- Intensive Care Medicine, CMC Ambroise Paré, Neuilly-sur-Seine 92200, France
| | - Manveer Singh
- Intensive Care Medicine, CMC Ambroise Paré, Neuilly-sur-Seine 92200, France
| | - Lee S Nguyen
- Research and Innovation, CMC Ambroise Paré, Neuilly-sur-Seine 92200, France
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Fang JS, Burt JM. Connexin37 Regulates Cell Cycle in the Vasculature. J Vasc Res 2022; 60:73-86. [PMID: 36067749 DOI: 10.1159/000525619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/08/2022] [Indexed: 11/19/2022] Open
Abstract
Control of vascular cell growth responses is critical for development and maintenance of a healthy vasculature. Connexins - the proteins comprising gap junction channels - are key regulators of cell growth in diseases such as cancer, but their involvement in controlling cell growth in the vasculature is less well appreciated. Connexin37 (Cx37) is one of four connexin isotypes expressed in the vessel wall. Its primary role in blood vessels relies on its unique ability to transduce flow-sensitive signals into changes in cell cycle status of endothelial (and perhaps, mural) cells. Here, we review available evidence for Cx37's role in the regulation of vascular growth, vessel organization, and vascular tone in healthy and diseased vasculature. We propose a novel mechanism whereby Cx37 accomplishes this with a phosphorylation-dependent transition between closed (growth-suppressive) and multiple open (growth-permissive) channel conformations that result from interactions of the C-terminus with cell-cycle regulators to limit or support cell cycle progression. Lastly, we discuss Cx37 and its downstream signaling as a novel potential target in the treatment of cardiovascular disease, and we address outstanding research questions that still challenge the development of such therapies.
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Affiliation(s)
- Jennifer S Fang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA
| | - Janis M Burt
- Department of Physiology, University of Arizona, Tucson, Arizona, USA
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Zhong C, Zhao H, Xie X, Qi Z, Li Y, Jia L, Zhang J, Lu Y. Protein Kinase C-Mediated Hyperphosphorylation and Lateralization of Connexin 43 Are Involved in Autoimmune Myocarditis-Induced Prolongation of QRS Complex. Front Physiol 2022; 13:815301. [PMID: 35418879 PMCID: PMC9000987 DOI: 10.3389/fphys.2022.815301] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/25/2022] [Indexed: 02/05/2023] Open
Abstract
Myocarditis is a serious and potentially life-threatening disease, which leads to cardiac dysfunction and sudden cardiac death. An increasing number of evidence suggests that myocarditis is also a malignant complication of coronavirus pneumonia, associated with heart failure and sudden cardiac death. Prolonged QRS complexes that are related to malignant arrhythmias caused by myocarditis significantly increase the risk of sudden cardiac death in patients. However, the molecular mechanisms are not fully known at present. In this study, we identify protein kinase C (PKC) as a new regulator of the QRS complex. In isolated hearts of normal rats, the PKC agonist, phorbol-12-myristate-13-acetate (PMA), induced prolongation of the QRS complex. Mechanistically, hyperphosphorylation and lateralization of connexin 43 (Cx43) by PKC induced depolymerization and internalization of Cx43 gap junction channels and prolongation of the QRS duration. Conversely, administration of the PKC inhibitor, Ro-32-0432, in experimental autoimmune myocarditis (EAM) rats after the most severe inflammation period still significantly rescued the stability of the Cx43 gap junction and alleviated prolongation of the QRS complex. Ro-32-0432 reduced phosphorylation and blocked translocation of Cx43 in EAM rat heart but did not regulate the mRNA expression level of ventricular ion channels and the other regulatory proteins, which indicates that the inhibition of PKC might have no protective effect on ion channels that generate ventricular action potential in EAM rats. These results suggest that the pharmacological inhibition of PKC ameliorates the prolongation of the QRS complex via suppression of Cx43 hyperphosphorylation, lateralization, and depolymerization of Cx43 gap junction channels in EAM rats, which provides a potential therapeutic strategy for myocarditis-induced arrhythmias.
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Affiliation(s)
- Chunlian Zhong
- School of Material and Chemical Engineering, Minjiang University, Fuzhou, China
- Fuzhou Institute of Oceanography, Fuzhou, China
| | - Huan Zhao
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Life Sciences, National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, China
| | - Xinwen Xie
- Liancheng County General Hospital, Longyan, China
| | - Zhi Qi
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Yumei Li
- School of Basic Medicine, Gannan Medical University, Ganzhou, China
| | - Lee Jia
- School of Material and Chemical Engineering, Minjiang University, Fuzhou, China
- Fuzhou Institute of Oceanography, Fuzhou, China
- *Correspondence: Lee Jia, ,
| | - Jinwei Zhang
- Xiamen Key Laboratory of Cardiovascular Disease, Xiamen Cardiovascular Hospital Xiamen University, Xiamen, China
- Hatherly Laboratories, Medical School, College of Medicine and Health, Institute of Biomedical and Clinical Sciences, University of Exeter, Exeter, United Kingdom
- Jinwei Zhang,
| | - Yusheng Lu
- School of Material and Chemical Engineering, Minjiang University, Fuzhou, China
- Fuzhou Institute of Oceanography, Fuzhou, China
- Yusheng Lu, ,
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Maneechote C, Palee S, Kerdphoo S, Jaiwongkam T, Chattipakorn SC, Chattipakorn N. Modulating mitochondrial dynamics attenuates cardiac ischemia-reperfusion injury in prediabetic rats. Acta Pharmacol Sin 2022; 43:26-38. [PMID: 33712720 PMCID: PMC8724282 DOI: 10.1038/s41401-021-00626-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 02/09/2021] [Indexed: 02/08/2023] Open
Abstract
Mitochondria are extraordinarily dynamic organelles that have a variety of morphologies, the status of which are controlled by the opposing processes of fission and fusion. Our recent study shows that inhibition of excessive mitochondrial fission by Drp1 inhibitor (Mdivi-1) leads to a reduction in infarct size and left ventricular (LV) dysfunction following cardiac ischemia-reperfusion (I/R) injury in high fat-fed induced pre-diabetic rats. In the present study, we investigated the cardioprotective effects of a mitochondrial fusion promoter (M1) and a combined treatment (M1 and Mdivi-1) in pre-diabetic rats. Wistar rats were given a high-fat diet for 12 weeks to induce prediabetes. The rats then subjected to 30 min-coronary occlusions followed by reperfusion for 120 min. These rats were intravenously administered M1 (2 mg/kg) or M1 (2 mg/kg) combined with Mdivi-1 (1.2 mg/kg) prior to ischemia, during ischemia or at the onset of reperfusion. We showed that administration of M1 alone or in combination with Mdivi-1 prior to ischemia, during ischemia or at the onset of reperfusion all significantly attenuated cardiac mitochondrial ROS production, membrane depolarization, swelling and dynamic imbalance, leading to reduced arrhythmias and infarct size, resulting in improved LV function in pre-diabetic rats. In conclusion, the promotion of mitochondrial fusion at any time-points during cardiac I/R injury attenuated cardiac mitochondrial dysfunction and dynamic imbalance, leading to decreased infarct size and improved LV function in pre-diabetic rats.
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Affiliation(s)
- Chayodom Maneechote
- grid.7132.70000 0000 9039 7662Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand ,grid.7132.70000 0000 9039 7662Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand ,grid.7132.70000 0000 9039 7662Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Siripong Palee
- grid.7132.70000 0000 9039 7662Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand ,grid.7132.70000 0000 9039 7662Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Sasiwan Kerdphoo
- grid.7132.70000 0000 9039 7662Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand ,grid.7132.70000 0000 9039 7662Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Thidarat Jaiwongkam
- grid.7132.70000 0000 9039 7662Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand ,grid.7132.70000 0000 9039 7662Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Siriporn C. Chattipakorn
- grid.7132.70000 0000 9039 7662Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand ,grid.7132.70000 0000 9039 7662Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Nipon Chattipakorn
- grid.7132.70000 0000 9039 7662Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand ,grid.7132.70000 0000 9039 7662Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand ,grid.7132.70000 0000 9039 7662Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200 Thailand
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Cx43 Promotes Endothelial Cell Migration and Angiogenesis via the Tyrosine Phosphatase SHP-2. Int J Mol Sci 2021; 23:ijms23010294. [PMID: 35008716 PMCID: PMC8745637 DOI: 10.3390/ijms23010294] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/21/2021] [Accepted: 12/24/2021] [Indexed: 12/16/2022] Open
Abstract
The gap junction protein connexin 43 (Cx43) is associated with increased cell migration and to related changes of the actin cytoskeleton, which is mediated via its C-terminal cytoplasmic tail and is independent of its channel function. Cx43 has been shown to possess an angiogenic potential, however, the role of Cx43 in endothelial cell migration has not yet been investigated. Here, we found that the knock-down of Cx43 by siRNA in human microvascular endothelial cells (HMEC) reduces migration, as assessed by a wound assay in vitro and impaired aortic vessel sprouting ex vivo. Immunoprecipitation of Cx43 revealed an interaction with the tyrosine phosphatase SHP-2, which enhanced its phosphatase activity, as observed in Cx43 expressing HeLa cells compared to cells treated with an empty vector. Interestingly, the expression of a dominant negative substrate trapping mutant SHP-2 (CS) in HMEC, via lentiviral transduction, also impaired endothelial migration to a similar extent as Cx43 siRNA compared to SHP-2 WT. Moreover, the reduction in endothelial migration upon Cx43 siRNA could not be rescued by the introduction of a constitutively active SHP-2 construct (EA). Our data demonstrate that Cx43 and SHP-2 mediate endothelial cell migration, revealing a novel interaction between Cx43 and SHP-2, which is essential for this process.
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Pecoraro M, Marzocco S, Popolo A. Diazoxide Needs Mitochondrial Connexin43 to Exert Its Cytoprotective Effect in a Cellular Model of CoCl 2-Induced Hypoxia. Int J Mol Sci 2021; 22:ijms222111599. [PMID: 34769027 PMCID: PMC8583808 DOI: 10.3390/ijms222111599] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/22/2021] [Accepted: 10/24/2021] [Indexed: 02/07/2023] Open
Abstract
Hypoxia is the leading cause of death in cardiomyocytes. Cells respond to oxygen deprivation by activating cytoprotective programs, such as mitochondrial connexin43 (mCx43) overexpression and the opening of mitochondrial KATP channels, aimed to reduce mitochondrial dysfunction. In this study we used an in vitro model of CoCl2-induced hypoxia to demonstrate that mCx43 and KATP channels cooperate to induce cytoprotection. CoCl2 administration induces apoptosis in H9c2 cells by increasing mitochondrial ROS production, intracellular and mitochondrial calcium overload and by inducing mitochondrial membrane depolarization. Diazoxide, an opener of KATP channels, reduces all these deleterious effects of CoCl2 only in the presence of mCx43. In fact, our results demonstrate that in the presence of radicicol, an inhibitor of Cx43 translocation to mitochondria, the cytoprotective effects of diazoxide disappear. In conclusion, these data confirm that there exists a close functional link between mCx43 and KATP channels.
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Duan J, Chen H, Li Y, Xu D, Li X, Zhang Z, Cheng J, Yang L, Li Q. 17β-Estradiol Enhances Porcine Meiosis Resumption from Autophagy-Induced Gap Junction Intercellular Communications and Connexin 43 Phosphorylation via the MEK/ERK Signaling Pathway. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:11847-11855. [PMID: 34609142 DOI: 10.1021/acs.jafc.1c04212] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Estrogen and its analogues are ubiquitous in agricultural environments, with large biological functions of oocyte development. Gap junction intercellular communications (GJICs) are the structural basis in cumulus-oocyte complexes (COCs) and regulate oocyte maturation and developmental material transport through a number of pathways. This study mainly determines the effect and potential mechanism of estrogen (17β-estradiol) in regulating GJICs in porcine COCs. In our study, 17β-estradiol increased porcine nuclear maturation in a time-dependent manner. The analysis revealed that 17β-estradiol upregulated the autophagy in COCs during in vitro maturation. In contrast with the control, 17β-estradiol decreased GJICs in a time-dependent manner between cumulus cells and oocytes, while it was consistent with the control group at 24 h. Carbenoxolone (CBX) blocks GJICs as a negative control group used in our system. Autophagy inhibitor autophinib decreased oocyte maturation, and the reduced nuclear maturation treated with autophinib was abolished by 17β-estradiol. Besides, the upregulation effect of autophinib on GJICs and transzonal projections (TZPs) was decreased by 17β-estradiol. 17β-Estradiol could reduce serine 368 phosphorylation of connexin 43 (Cx43) protein by autophinib in porcine COCs. These results were dependent upon the MEK/ERK signaling pathway. Furthermore, 17β-estradiol-induced GJICs and Cx43 phosphorylation were inhibited by autophinib or the MEK/ERK pathway inhibitors (Trametinib and FR 180204), indicating that 17β-estradiol regulated GJICs through the MEK/ERK signaling pathway. In conclusion, 17β-estradiol improves the autophagy-mediated nuclear maturation with downregulating GJICs and TZPs in porcine COCs. Such an effect occurs by phosphorylation of Cx43, which was regulated via the MEK/ERK signaling pathway.
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Affiliation(s)
- Jiaxin Duan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang, Shaanxi 712100, People's Republic of China
| | - Huali Chen
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621000, People's Republic of China
| | - Yuan Li
- College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang, Shaanxi 712100, People's Republic of China
| | - Dejun Xu
- College of Animal Science and Technology, Southwest University, Chongqing, Sichuan 400000, People's Republic of China
| | - Xiaoya Li
- College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang, Shaanxi 712100, People's Republic of China
| | - Zelin Zhang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang, Shaanxi 712100, People's Republic of China
| | - Jianyong Cheng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang, Shaanxi 712100, People's Republic of China
| | - Li Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang, Shaanxi 712100, People's Republic of China
| | - Qingwang Li
- College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang, Shaanxi 712100, People's Republic of China
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Ai X, Yan J, Pogwizd SM. Serine-threonine protein phosphatase regulation of Cx43 dephosphorylation in arrhythmogenic disorders. Cell Signal 2021; 86:110070. [PMID: 34217833 PMCID: PMC8963383 DOI: 10.1016/j.cellsig.2021.110070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/11/2021] [Accepted: 06/29/2021] [Indexed: 12/11/2022]
Abstract
Regulation of cell-to-cell communication in the heart by the gap junction protein Connexin43 (Cx43) involves modulation of Cx43 phosphorylation state by protein kinases, and dephosphorylation by protein phosphatases. Dephosphorylation of Cx43 has been associated with impaired intercellular coupling and enhanced arrhythmogenesis in various pathologic states. While there has been extensive study of the protein kinases acting on Cx43, there has been limited studies of the protein phosphatases that may underlie Cx43 dephosphorylation. The focus of this review is to introduce serine-threonine protein phosphatase regulation of Cx43 phosphorylation state and cell-to-cell communication, and its impact on arrhythmogenesis in the setting of chronic heart failure and myocardial ischemia, as well as on atrial fibrillation. We also discuss the therapeutic potential of modulating protein phosphatases to treat arrhythmias in these clinical settings.
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Affiliation(s)
- Xun Ai
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Jiajie Yan
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Steven M Pogwizd
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States of America.
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Remodeling of Cardiac Gap Junctional Cell-Cell Coupling. Cells 2021; 10:cells10092422. [PMID: 34572071 PMCID: PMC8465208 DOI: 10.3390/cells10092422] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/03/2021] [Accepted: 09/08/2021] [Indexed: 12/29/2022] Open
Abstract
The heart works as a functional syncytium, which is realized via cell-cell coupling maintained by gap junction channels. These channels connect two adjacent cells, so that action potentials can be transferred. Each cell contributes a hexameric hemichannel (=connexon), formed by protein subuntis named connexins. These hemichannels dock to each other and form the gap junction channel. This channel works as a low ohmic resistor also allowing the passage of small molecules up to 1000 Dalton. Connexins are a protein family comprising of 21 isoforms in humans. In the heart, the main isoforms are Cx43 (the 43 kDa connexin; ubiquitous), Cx40 (mostly in atrium and specific conduction system), and Cx45 (in early developmental states, in the conduction system, and between fibroblasts and cardiomyocytes). These gap junction channels are mainly located at the polar region of the cardiomyocytes and thus contribute to the anisotropic pattern of cardiac electrical conductivity. While in the beginning the cell–cell coupling was considered to be static, similar to an anatomically defined structure, we have learned in the past decades that gap junctions are also subject to cardiac remodeling processes in cardiac disease such as atrial fibrillation, myocardial infarction, or cardiomyopathy. The underlying remodeling processes include the modulation of connexin expression by e.g., angiotensin, endothelin, or catecholamines, as well as the modulation of the localization of the gap junctions e.g., by the direction and strength of local mechanical forces. A reduction in connexin expression can result in a reduced conduction velocity. The alteration of gap junction localization has been shown to result in altered pathways of conduction and altered anisotropy. In particular, it can produce or contribute to non-uniformity of anisotropy, and thereby can pre-form an arrhythmogenic substrate. Interestingly, these remodeling processes seem to be susceptible to certain pharmacological treatment.
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Ahmed F, Rahman M, Thompson R, Bereiter DA. Role of Connexin 43 in an Inflammatory Model for TMJ Hyperalgesia. FRONTIERS IN PAIN RESEARCH 2021; 2:715871. [PMID: 35295418 PMCID: PMC8915650 DOI: 10.3389/fpain.2021.715871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/08/2021] [Indexed: 12/27/2022] Open
Abstract
Temporomandibular joint disorders (TMD) consist of a heterogeneous group of conditions that present with pain in the temporomandibular joint (TMJ) region and muscles of mastication. This project assessed the role of connexin 43 (Cx43), a gap junction protein, in the trigeminal ganglion (TG) in an animal model for persistent inflammatory TMJ hyperalgesia. Experiments were performed in male and female rats to determine if sex differences influence the expression and/or function of Cx43 in persistent TMJ hyperalgesia. Intra-TMJ injection of Complete Freund's Adjuvant (CFA) caused a significant increase in Cx43 expression in the TG at 4 days and 10 days post-injection in ovariectomized (OvX) female rats and OvX females treated with estradiol (OvXE), while TG samples in males revealed only marginal increases. Intra-TG injection of interference RNA for Cx43 (siRNA Cx43) 3 days prior to recording, markedly reduced TMJ-evoked masseter muscle electromyographic (MMemg) activity in all CFA-inflamed rats, while activity in sham animals was not affected. Western blot analysis revealed that at 3 days after intra-TG injection of siRNA Cx43 protein levels for Cx43 were significantly reduced in TG samples of all CFA-inflamed rats. Intra-TG injection of the mimetic peptide GAP19, which inhibits Cx43 hemichannel formation, greatly reduced TMJ-evoked MMemg activity in all CFA-inflamed groups, while activity in sham groups was not affected. These results revealed that TMJ inflammation caused a persistent increase in Cx43 protein in the TG in a sex-dependent manner. However, intra-TG blockade of Cx43 by siRNA or by GAP19 significantly reduced TMJ-evoked MMemg activity in both males and females following TMJ inflammation. These results indicated that Cx43 was necessary for enhanced jaw muscle activity after TMJ inflammation in males and females, a result that could not be predicted on the basis of TG expression of Cx43 alone.
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Lee CC, Chen WT, Chen SY, Lee TM. Dapagliflozin attenuates arrhythmic vulnerabilities by regulating connexin43 expression via the AMPK pathway in post-infarcted rat hearts. Biochem Pharmacol 2021; 192:114674. [PMID: 34252408 DOI: 10.1016/j.bcp.2021.114674] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/28/2021] [Accepted: 07/06/2021] [Indexed: 12/13/2022]
Abstract
We have demonstrated that dapagliflozin, a sodium-glucose cotransporter (SGLT) 2 inhibitor, attenuates reactive oxygen species (ROS) production. Connexin43 playing a role in ventricular arrhythmia is sensitive to redox status. No data are available on the effects of dapagliflozin on arrhythmogenesis. This study was to determine whether dapagliflozin attenuated arrhythmias through modulating AMP-activated protein kinase (AMPK)/free radicals-induced connexin43 after myocardial infarction. After coronary ligation, normoglycemic male Wistar rats were randomized to either vehicle or dapagliflozin (0.1 mg/kg per day) for 4 weeks. Myocardial ROS levels were significantly increased (p < 0.05) and connexin43 levels were substantially decreased after myocardial infarction (p < 0.05). Dapagliflozin administration was associated with increased SGLT1, attenuated ROS and increased connexin43 levels in myocardium (all p < 0.05). During programmed electrical stimulation, arrhythmic severity was significantly improved in the dapagliflozin-treated infarcted rats than those in the vehicle-treated infarcted rats (p < 0.05). Dapagliflozin significantly increased AMPK phosphorylation compared to vehicle after infarction (p < 0.05). Inhibition of AMPK signaling by SBI-0206965 prevented increased SGLT1 and blocked the effects of dapagliflozin on attenuated ROS levels and increased connexin43 phosphorylation (all p < 0.05). SGLT1 inhibited by KGA-2727 showed attenuated ROS levels and increased connexin43 phosphorylation (both p < 0.05) although AMPK phosphorylation was not changed, implying SGLT1 activation was mediated by AMPK in dapagliflozin-treated hearts. Dapagliflozin-treated hearts had significantly increased connexin43 phosphorylation (p < 0.05), which was significantly decreased after adding 3-morpholinosydnonimine (p < 0.05). These data indicate that clinically-relevant dapagliflozin concentrations decreased free radicals content and increased connexin43 levels through AMPK-dependent and SGLT1-independent mechanisms, which attenuated ventricular arrhythmias in the normoglycemic infarcted rats.
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Affiliation(s)
| | - Wei-Ting Chen
- Cardiovascular Institute, An Nan Hospital, China Medical University, Tainan, Taiwan
| | - Syue-Yi Chen
- Cardiovascular Institute, An Nan Hospital, China Medical University, Tainan, Taiwan
| | - Tsung-Ming Lee
- Cardiovascular Institute, An Nan Hospital, China Medical University, Tainan, Taiwan; Department of Medicine, China Medical University, Taichung, Taiwan.
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He J, Gong M, Wang Z, Liu D, Xie B, Luo C, Li G, Tse G, Liu T. Cardiac abnormalities after induction of endoplasmic reticulum stress are associated with mitochondrial dysfunction and connexin43 expression. Clin Exp Pharmacol Physiol 2021; 48:1371-1381. [PMID: 34133785 DOI: 10.1111/1440-1681.13541] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 05/30/2021] [Accepted: 06/09/2021] [Indexed: 02/06/2023]
Abstract
The endoplasmic reticulum (ER) is responsible for protein synthesis and calcium storage. ER stress, reflected by protein unfolding and calcium handling abnormalities, has been studied as a pathogenic factor in cardiovascular diseases. The aim of this study is to examine the effects of ER stress on mechanical and electrophysiological functions in the heart and explore the underlying molecular mechanisms. A total of 30 rats were randomly divided into control, ER stress inducer (tunicamycin[TN]) and ER stress inhibitor (tunicamycin+4-phenylbutyric acid [4-PBA]) groups. ER stress induction led to significantly systolic and diastolic dysfunction as reflected by maximal increasing/decreasing rate of left intraventricular pressure (±dp/dt), left ventricular peaksystolic pressure(LVSP) and LV end-diastolic pressure(LVEDP). Epicardial mapping performed in vivo revealed reduced conduction velocity and increased conduction heterogeneity associated with the development of spontaneous ventricular tachycardia. Masson's trichrome staining revealed marked fibrosis in the myocardial interstitial and sub-pericardial regions, and thickened epicardium. Western blot analysis revealed increased pro-fibrotic factor transforming growth factor-β1 (TGF-β1), decreased mitochondrial biogenesis protein peroxlsome proliferator-activated receptor-γ coactlvator-1α (PGC-1a), and decreased mitochondrial fusion protein mitofusin-2 (MFN2). These changes were associated with mitochondria dysfunction and connexin 43(CX43)translocation to mitochondria. These abnormalities can be partially prevented by the ER stress inhibitor 4-PBA. Our study shows that ER stress induction can produce cardiac electrical and mechanism dysfunction as well as structural remodelling. Mitochondrial function alterations are contributed by CX43 transposition to mitochondria. These abnormalities can be partially prevented by the ER stress inhibitor 4-PBA.
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Affiliation(s)
- Jinli He
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Mengqi Gong
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China.,Department of Cardiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zaojia Wang
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Daiqi Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Bingxin Xie
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Cunjin Luo
- School of Computer Science and Electronic Engineering, University of Essex, Colchester, UK
| | - Guangping Li
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.,Kent and Medway Medical School, Canterbury, UK
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
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Omega-3 PUFAs Suppress IL-1β-Induced Hyperactivity of Immunoproteasomes in Astrocytes. Int J Mol Sci 2021; 22:ijms22115410. [PMID: 34063751 PMCID: PMC8196670 DOI: 10.3390/ijms22115410] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/16/2021] [Accepted: 05/19/2021] [Indexed: 12/14/2022] Open
Abstract
The role of immunoproteasome (iP) in astroglia, the cellular component of innate immunity, has not been clarified. The results so far indicate that neuroinflammation, a prominent hallmark of Alzheimer’s disease, strongly activates the iP subunits expression. Since omega-3 PUFAs possess anti-inflammatory and pro-resolving activity in the brain, we investigated the effect of DHA and EPA on the gene expression of constitutive (β1 and β5) and inducible (iβ1/LMP2 and iβ5/LMP7) proteasome subunits and proteasomal activity in IL-1β-stimulated astrocytes. We found that both PUFAs downregulated the expression of IL-1β-induced the iP subunits, but not the constitutive proteasome subunits. The chymotrypsin-like activity was inhibited in a dose-dependent manner by DHA, and much strongly in the lower concentration by EPA. Furthermore, we established that C/EBPα and C/EBPβ transcription factors, being the cis-regulatory element of the transcription complex, frequently activated by inflammatory mediators, participate in a reduction in the iP subunits’ expression. Moreover, the expression of connexin 43 the major gap junction protein in astrocytes, negatively regulated by IL-1β was markedly increased in PUFA-treated cells. These findings indicate that omega-3 PUFAs attenuate inflammation-induced hyperactivity of iPs in astrocytes and have a beneficial effect on preservation of interastrocytic communication by gap junctions.
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Marsh SR, Williams ZJ, Pridham KJ, Gourdie RG. Peptidic Connexin43 Therapeutics in Cardiac Reparative Medicine. J Cardiovasc Dev Dis 2021; 8:52. [PMID: 34063001 PMCID: PMC8147937 DOI: 10.3390/jcdd8050052] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/19/2021] [Accepted: 05/01/2021] [Indexed: 12/12/2022] Open
Abstract
Connexin (Cx43)-formed channels have been linked to cardiac arrhythmias and diseases of the heart associated with myocardial tissue loss and fibrosis. These pathologies include ischemic heart disease, ischemia-reperfusion injury, heart failure, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and Duchenne muscular dystrophy. A number of Cx43 mimetic peptides have been reported as therapeutic candidates for targeting disease processes linked to Cx43, including some that have advanced to clinical testing in humans. These peptides include Cx43 sequences based on the extracellular loop domains (e.g., Gap26, Gap 27, and Peptide5), cytoplasmic-loop domain (Gap19 and L2), and cytoplasmic carboxyl-terminal domain (e.g., JM2, Cx43tat, CycliCX, and the alphaCT family of peptides) of this transmembrane protein. Additionally, RYYN peptides binding to the Cx43 carboxyl-terminus have been described. In this review, we survey preclinical and clinical data available on short mimetic peptides based on, or directly targeting, Cx43, with focus on their potential for treating heart disease. We also discuss problems that have caused reluctance within the pharmaceutical industry to translate peptidic therapeutics to the clinic, even when supporting preclinical data is strong. These issues include those associated with the administration, stability in vivo, and tissue penetration of peptide-based therapeutics. Finally, we discuss novel drug delivery technologies including nanoparticles, exosomes, and other nanovesicular carriers that could transform the clinical and commercial viability of Cx43-targeting peptides in treatment of heart disease, stroke, cancer, and other indications requiring oral or parenteral administration. Some of these newly emerging approaches to drug delivery may provide a path to overcoming pitfalls associated with the drugging of peptide therapeutics.
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Affiliation(s)
- Spencer R. Marsh
- Fralin Biomedical Research Institute at VTC, Virginia Tech, Roanoke, VA 24016, USA; (S.R.M.); (Z.J.W.); (K.J.P.)
- Center for Heart and Reparative Medicine Research, Virginia Tech, Roanoke, VA 24016, USA
| | - Zachary J. Williams
- Fralin Biomedical Research Institute at VTC, Virginia Tech, Roanoke, VA 24016, USA; (S.R.M.); (Z.J.W.); (K.J.P.)
- Center for Heart and Reparative Medicine Research, Virginia Tech, Roanoke, VA 24016, USA
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Roanoke, VA 24016, USA
| | - Kevin J. Pridham
- Fralin Biomedical Research Institute at VTC, Virginia Tech, Roanoke, VA 24016, USA; (S.R.M.); (Z.J.W.); (K.J.P.)
- Center for Heart and Reparative Medicine Research, Virginia Tech, Roanoke, VA 24016, USA
| | - Robert G. Gourdie
- Fralin Biomedical Research Institute at VTC, Virginia Tech, Roanoke, VA 24016, USA; (S.R.M.); (Z.J.W.); (K.J.P.)
- Center for Heart and Reparative Medicine Research, Virginia Tech, Roanoke, VA 24016, USA
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Emergency Medicine, Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA
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Connexins in the Heart: Regulation, Function and Involvement in Cardiac Disease. Int J Mol Sci 2021; 22:ijms22094413. [PMID: 33922534 PMCID: PMC8122935 DOI: 10.3390/ijms22094413] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/12/2021] [Accepted: 04/20/2021] [Indexed: 12/20/2022] Open
Abstract
Connexins are a family of transmembrane proteins that play a key role in cardiac physiology. Gap junctional channels put into contact the cytoplasms of connected cardiomyocytes, allowing the existence of electrical coupling. However, in addition to this fundamental role, connexins are also involved in cardiomyocyte death and survival. Thus, chemical coupling through gap junctions plays a key role in the spreading of injury between connected cells. Moreover, in addition to their involvement in cell-to-cell communication, mounting evidence indicates that connexins have additional gap junction-independent functions. Opening of unopposed hemichannels, located at the lateral surface of cardiomyocytes, may compromise cell homeostasis and may be involved in ischemia/reperfusion injury. In addition, connexins located at non-canonical cell structures, including mitochondria and the nucleus, have been demonstrated to be involved in cardioprotection and in regulation of cell growth and differentiation. In this review, we will provide, first, an overview on connexin biology, including their synthesis and degradation, their regulation and their interactions. Then, we will conduct an in-depth examination of the role of connexins in cardiac pathophysiology, including new findings regarding their involvement in myocardial ischemia/reperfusion injury, cardiac fibrosis, gene transcription or signaling regulation.
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Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy. Int J Mol Sci 2021; 22:ijms22083860. [PMID: 33917911 PMCID: PMC8068229 DOI: 10.3390/ijms22083860] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/02/2021] [Accepted: 04/04/2021] [Indexed: 12/11/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.
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Khuanjing T, Palee S, Kerdphoo S, Jaiwongkam T, Anomasiri A, Chattipakorn SC, Chattipakorn N. Donepezil attenuated cardiac ischemia/reperfusion injury through balancing mitochondrial dynamics, mitophagy, and autophagy. Transl Res 2021; 230:82-97. [PMID: 33137536 DOI: 10.1016/j.trsl.2020.10.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 10/06/2020] [Accepted: 10/28/2020] [Indexed: 02/08/2023]
Abstract
Cardiac autonomic imbalance including sympathetic overactivity and diminished parasympathetic activity is associated with left ventricular (LV) dysfunction in cases of cardiac ischemia/reperfusion (I/R) injury. Electrical stimulation to increase vagal activity has been shown to reduce infarct size and decrease fatal arrhythmias in cardiac I/R injury. However, the benefits of a parasympathomimetic drug on the heart during I/R are unclear. We hypothesized that administration of donepezil provides cardioprotection in cardiac I/R injury via reducing cellular apoptosis, oxidative stress, mitochondrial dysfunction, mitochondrial dynamic imbalance, increasing autophagy, and mitophagy. Fifty-four male Wistar rats were randomly assigned into sham and I/R groups. Acute cardiac I/R injury was induced by 30-minutes left anterior descending (LAD) coronary artery occlusion followed by 120-minutes reperfusion. These rats with induced I/R injury were randomly assigned to be treated with either: (1) Saline (vehicle group) or donepezil 3 mg/kg via intravenous injection given (2) before ischemia, (3) during ischemia, or (4) at the onset of reperfusion. Rats with cardiac I/R injury showed an increase in infarct size and arrhythmia score, LV dysfunction, impaired mitochondrial dynamic balance, autophagy and mitophagy, mitochondrial dysfunction, and increased apoptosis. All the donepezil-treated rats, regardless of the time of administration, showed a similar reduction in these impairments, and rebalancing in cardiac mitochondrial dynamics, leading to reduced myocardial infarct size and arrhythmia, and improved LV function. These findings suggested that donepezil effectively protected the heart against I/R injury through cardiac mitochondrial protection regardless of the time of administration.
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Affiliation(s)
- Thawatchai Khuanjing
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand
| | - Siripong Palee
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand
| | - Sasiwan Kerdphoo
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand
| | - Thidarat Jaiwongkam
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand
| | - Anawin Anomasiri
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Siriporn C Chattipakorn
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand
| | - Nipon Chattipakorn
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand.
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Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia, largely associated to morbidity and mortality. Over the past decades, research in appearance and progression of this arrhythmia have turned into significant advances in its management. However, the incidence of AF continues to increase with the aging of the population and many important fundamental and translational underlaying mechanisms remain elusive. Here, we review recent advances in molecular and cellular basis for AF initiation, maintenance and progression. We first provide an overview of the basic molecular and electrophysiological mechanisms that lead and characterize AF. Next, we discuss the upstream regulatory factors conducting the underlying mechanisms which drive electrical and structural AF-associated remodeling, including genetic factors (risk variants associated to AF as transcriptional regulators and genetic changes associated to AF), neurohormonal regulation (i.e., cAMP) and oxidative stress imbalance (cGMP and mitochondrial dysfunction). Finally, we discuss the potential therapeutic implications of those findings, the knowledge gaps and consider future approaches to improve clinical management.
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Barnett SD, Asif H, Anderson M, Buxton ILO. Novel Tocolytic Strategy: Modulating Cx43 Activity by S-Nitrosation. J Pharmacol Exp Ther 2021; 376:444-453. [PMID: 33384302 PMCID: PMC7919864 DOI: 10.1124/jpet.120.000427] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 12/23/2020] [Indexed: 12/13/2022] Open
Abstract
Currently available tocolytics are ineffective at significantly delaying preterm birth. This is due in part to our failure to better understand the mechanisms that drive spontaneous preterm labor (sPTL). Cyclic nucleotides are not the primary contributors to myometrial quiescence, but instead nitric oxide (NO)-mediated protein S-nitrosation (SNO) is integral to the relaxation of the tissue. Connexin-43 (Cx43), a myometrial "contractile-associated protein" that functions as either a gap junction channel or an hemichannel (HC), was the focus of this study. Protein analysis determined that Cx43 is downregulated in sPTL myometrium. Furthermore, Cx43 is S-nitrosated by NO, which correlates with an increase of phosphorylated Cx43 at serine 368 (Cx43-pS368 -gap junction inhibition) as well as an increase in the HC open-state probability (quiescence). Pharmacologic inhibition of Cx43 with 18β-glycyrrhetinic acid (18β-GA) exhibits a negative inotropic effect on the myometrium in a dose-dependent manner, as does administration of nebivolol, an NO synthase activator that increases total protein SNOs. When 18β-GA and nebivolol were coadministered at their IC50 values, the effect on contractile dynamics was additive and all but eliminated contractions. The development of new tocolytics demands a better understanding of the underlying mechanisms of sPTL. Here it has been shown that 18β-GA and nebivolol leverage dysregulated pathways in the myometrium, resulting in a novel approach for the treatment of sPTL. SIGNIFICANCE STATEMENT: Although there are many known causes of preterm labor (PTL), the mechanisms of "spontaneous" PTL (sPTL) remain obfuscated, which is why treating this condition is so challenging. Here we have identified that connexin-43 (Cx43), an important contractile-associated protein, is dysregulated in sPTL myometrium and that the pharmacologic inhibition of Cx43 and its S-nitrosation with 18β-glycyrrhetinic acid and nebivolol, respectively, significantly blunts contraction in human myometrial tissue, presenting a novel approach to tocolysis that leverages maladjusted pathways in women who experience sPTL.
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Affiliation(s)
- Scott D Barnett
- Department of Pharmacology, Myometrial Function Group, University of Nevada, Reno School of Medicine, Reno, NV
| | - Hazik Asif
- Department of Pharmacology, Myometrial Function Group, University of Nevada, Reno School of Medicine, Reno, NV
| | - Mitchell Anderson
- Department of Pharmacology, Myometrial Function Group, University of Nevada, Reno School of Medicine, Reno, NV
| | - Iain L O Buxton
- Department of Pharmacology, Myometrial Function Group, University of Nevada, Reno School of Medicine, Reno, NV
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A Cellular Assay for the Identification and Characterization of Connexin Gap Junction Modulators. Int J Mol Sci 2021; 22:ijms22031417. [PMID: 33572565 PMCID: PMC7866863 DOI: 10.3390/ijms22031417] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 12/18/2022] Open
Abstract
Connexin gap junctions (Cx GJs) enable the passage of small molecules and ions between cells and are therefore important for cell-to-cell communication. Their dysfunction is associated with diseases, and small molecules acting as modulators of GJs may therefore be useful as therapeutic drugs. To identify GJ modulators, suitable assays are needed that allow compound screening. In the present study, we established a novel assay utilizing HeLa cells recombinantly expressing Cx43. Donor cells additionally expressing the Gs protein-coupled adenosine A2A receptor, and biosensor cells expressing a cAMP-sensitive GloSensor luciferase were established. Adenosine A2A receptor activation in the donor cells using a selective agonist results in intracellular cAMP production. The negatively charged cAMP migrates via the Cx43 gap junctions to the biosensor cells and can there be measured by the cAMP-dependent luminescence signal. Cx43 GJ modulators can be expected to impact the transfer of cAMP from the donor to the biosensor cells, since cAMP transit is only possible via GJs. The new assay was validated by testing the standard GJ inhibitor carbenoxolon, which showed a concentration-dependent inhibition of the signal and an IC50 value that was consistent with previously reported values. The assay was demonstrated to be suitable for high-throughput screening.
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Astroglial Connexin43 as a Potential Target for a Mood Stabiliser. Int J Mol Sci 2020; 22:ijms22010339. [PMID: 33396966 PMCID: PMC7795839 DOI: 10.3390/ijms22010339] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/24/2020] [Accepted: 12/27/2020] [Indexed: 02/06/2023] Open
Abstract
Mood disorders remain a major public health concern worldwide. Monoaminergic hypotheses of pathophysiology of bipolar and major depressive disorders have led to the development of monoamine transporter-inhibiting antidepressants for the treatment of major depression and have contributed to the expanded indications of atypical antipsychotics for the treatment of bipolar disorders. In spite of psychopharmacological progress, current pharmacotherapy according to the monoaminergic hypothesis alone is insufficient to improve or prevent mood disorders. Recent approval of esketamine for treatment of treatment-resistant depression has attracted attention in psychopharmacology as a glutamatergic hypothesis of the pathophysiology of mood disorders. On the other hand, in the last decade, accumulated findings regarding the pathomechanisms of mood disorders emphasised that functional abnormalities of tripartite synaptic transmission play important roles in the pathophysiology of mood disorders. At first glance, the enhancement of astroglial connexin seems to contribute to antidepressant and mood-stabilising effects, but in reality, antidepressive and mood-stabilising actions are mediated by more complicated interactions associated with the astroglial gap junction and hemichannel. Indeed, several depressive mood-inducing stress stimulations suppress connexin43 expression and astroglial gap junction function, but enhance astroglial hemichannel activity. On the other hand, monoamine transporter-inhibiting antidepressants suppress astroglial hemichannel activity and enhance astroglial gap junction function, whereas several non-antidepressant mood stabilisers activate astroglial hemichannel activity. Based on preclinical findings, in this review, we summarise the effects of antidepressants, mood-stabilising antipsychotics, and anticonvulsants on astroglial connexin, and then, to establish a novel strategy for treatment of mood disorders, we reveal the current progress in psychopharmacology, changing the question from "what has been revealed?" to "what should be clarified?".
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