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King DR, Sedovy MW, Leng X, Xue J, Lamouille S, Koval M, Isakson BE, Johnstone SR. Mechanisms of Connexin Regulating Peptides. Int J Mol Sci 2021; 22:ijms221910186. [PMID: 34638526 PMCID: PMC8507914 DOI: 10.3390/ijms221910186] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 12/22/2022] Open
Abstract
Gap junctions (GJ) and connexins play integral roles in cellular physiology and have been found to be involved in multiple pathophysiological states from cancer to cardiovascular disease. Studies over the last 60 years have demonstrated the utility of altering GJ signaling pathways in experimental models, which has led to them being attractive targets for therapeutic intervention. A number of different mechanisms have been proposed to regulate GJ signaling, including channel blocking, enhancing channel open state, and disrupting protein-protein interactions. The primary mechanism for this has been through the design of numerous peptides as therapeutics, that are either currently in early development or are in various stages of clinical trials. Despite over 25 years of research into connexin targeting peptides, the overall mechanisms of action are still poorly understood. In this overview, we discuss published connexin targeting peptides, their reported mechanisms of action, and the potential for these molecules in the treatment of disease.
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Affiliation(s)
- D. Ryan King
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
| | - Meghan W. Sedovy
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
- Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Blacksburg, VA 24061, USA
| | - Xinyan Leng
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
| | - Jianxiang Xue
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; (J.X.); (B.E.I.)
| | - Samy Lamouille
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
- Center for Vascular and Heart Research, Virginia Tech, Roanoke, VA 24016, USA
| | - Michael Koval
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
| | - Brant E. Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; (J.X.); (B.E.I.)
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Scott R. Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
- Center for Vascular and Heart Research, Virginia Tech, Roanoke, VA 24016, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA
- Correspondence:
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Jost N, Christ T, Magyar J. New Strategies for the Treatment of Atrial Fibrillation. Pharmaceuticals (Basel) 2021; 14:ph14090926. [PMID: 34577626 PMCID: PMC8466466 DOI: 10.3390/ph14090926] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in the clinical practice. It significantly contributes to the morbidity and mortality of the elderly population. Over the past 25-30 years intense effort in basic research has advanced the understanding of the relationship between the pathophysiology of AF and atrial remodelling. Nowadays it is clear that the various forms of atrial remodelling (electrical, contractile and structural) play crucial role in initiating and maintaining the persistent and permanent types of AF. Unlike in ventricular fibrillation, in AF rapid ectopic firing originating from pulmonary veins and re-entry mechanism may induce and maintain (due to atrial remodelling) this complex cardiac arrhythmia. The present review presents and discusses in detail the latest knowledge on the role of remodelling in AF. Special attention is paid to novel concepts and pharmacological targets presumably relevant to the drug treatment of atrial fibrillation.
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Affiliation(s)
- Norbert Jost
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, 6725 Szeged, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6725 Szeged, Hungary
- ELKH-SZTE Research Group for Cardiovascular Pharmacology, Eötvös Loránd Research Network, 6725 Szeged, Hungary
- Correspondence:
| | - Torsten Christ
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany;
- DZHK (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary;
- Department of Sport Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
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Nugent L, Ofori-Frimpong B, Martin PE, Green CR, Wright CS. Cx31.1 expression is modulated in HaCaT cells exposed to UV-induced damage and scrape-wounding. J Cell Physiol 2020; 236:911-920. [PMID: 32592185 DOI: 10.1002/jcp.29901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 05/22/2020] [Accepted: 06/13/2020] [Indexed: 02/02/2023]
Abstract
Connexin31.1 (Cx31.1) is a gap junction protein associated with apoptosis. In the skin, apoptosis is modulated by diabetes. A HaCaT skin model investigated whether normal (NGI) and high glucose and insulin (HGI; diabetic) conditions altered Cx31.1 expression, and if these were apoptosis linked. Cx31.1 was found in HaCaT and HeLa Ohio cells, with HaCaT Cx31.1 protein increased in HGI conditions, and around apoptotic cells. HeLa Cx31.1 channels were noncommunicative. Post scrape-wounding, Cx31.1 increased at wound edges. Caspase 3/7 in scrape-wounds media (containing cells) elevated in HGI. UV exposure raised Cx31.1, and caspase 3/7, in NGI and HGI. UV reduced cell viability in NGI cells, although not significantly in HGI. Cx31.1 is modulated during HaCaT cell wound closure, and associated with 'diabetic' conditions. Cx31.1 expression matched apoptosis levels, higher in HGI cultures. Cx31.1 is noncommunicating, modulated after wounding, linked to apoptosis, and may be associated with tissue turn-over around diabetic wounds.
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Affiliation(s)
- Louise Nugent
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Boatemaa Ofori-Frimpong
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Patricia E Martin
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Colin R Green
- Department of Opthamology, School of Medicine, University of Auckland, Auckland, New Zealand
| | - Catherine S Wright
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
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Yang W, Lampe PD, Kensel-Hammes P, Hesson J, Ware CB, Crisa L, Cirulli V. Connexin 43 Functions as a Positive Regulator of Stem Cell Differentiation into Definitive Endoderm and Pancreatic Progenitors. iScience 2019; 19:450-460. [PMID: 31430690 PMCID: PMC6708988 DOI: 10.1016/j.isci.2019.07.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 05/04/2019] [Accepted: 07/18/2019] [Indexed: 01/05/2023] Open
Abstract
Efficient stem cell differentiation into pancreatic islet cells is of critical importance for the development of cell replacement therapies for diabetes. Here, we identify the expression pattern of connexin 43 (Cx43), a gap junction (GJ) channel protein, in human embryonic stem cell (hESC)-derived definitive endoderm (DE) and primitive gut tube cells, representing early lineages for posterior foregut (PF), pancreatic progenitors (PP), pancreatic endocrine progenitors (PE), and islet cells. As the function of GJ channels is dependent on their gating status, we tested the impact of supplementing hESC-derived PP cell cultures with AAP10, a peptide that promotes Cx43 GJ channel opening. We found that this treatment promotes the expression of DE markers FoxA2 and Sox17, leads to a more efficient derivation of DE, and improves the yield of PF, PP, and PE cells. These results demonstrate a functional involvement of GJ channels in the differentiation of embryonic stem cells into pancreatic cell lineages.
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Affiliation(s)
- Wendy Yang
- Department of Medicine, UW Diabetes Institute, University of Washington, 850 Republican Street, S475, Seattle, WA 98109, USA
| | - Paul D Lampe
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Patricia Kensel-Hammes
- Department of Medicine, UW Diabetes Institute, University of Washington, 850 Republican Street, S475, Seattle, WA 98109, USA
| | - Jennifer Hesson
- Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, S480, Seattle, WA 98109, USA
| | - Carol B Ware
- Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, S480, Seattle, WA 98109, USA
| | - Laura Crisa
- Department of Medicine, UW Diabetes Institute, University of Washington, 850 Republican Street, S475, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, S480, Seattle, WA 98109, USA; Department of Pharmacology, University of Washington, Seattle, WA, USA.
| | - Vincenzo Cirulli
- Department of Medicine, UW Diabetes Institute, University of Washington, 850 Republican Street, S475, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, S480, Seattle, WA 98109, USA; Department of Pharmacology, University of Washington, Seattle, WA, USA.
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Anichkov NM, Sydikov AA, Chuprov IN, Zaslavsky DV, Nasyrov RA. [Role of intercellular slit-like contacts (connexins) in the pathogenesis of erythroderma]. Arkh Patol 2018; 80:61-64. [PMID: 30059073 DOI: 10.17116/patol201880461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Erythroderma is a skin lesion characterized by redness, swelling, infiltration, and desquamation of greater than 90% of the skin. The etiology of erythroderma is not completely clear and the lesion can be manifestations of various chronic dermatoses, including atopic dermatitis, psoriasis, eczema, and toxicodermia, and be represented by erythrodermic mycosis fungoides. The pathogenesis of erythroderma especially at the genetic level remains little studied. Thus, one disease (erythroderma) can be a manifestation of different dermatoses and have similar clinical and histological signs. This paper gives a review of modern literature on the study of erythroderma in terms of morphology and genetic aspects.
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Affiliation(s)
- N M Anichkov
- I.I. Mechnikov North-Western State Medical University, Ministry of Health of Russia, Saint Petersburg, Russia
| | - A A Sydikov
- Saint Petersburg State Pediatric Medical University, Ministry of Health of Russia, Saint Petersburg, Russia
| | - I N Chuprov
- I.I. Mechnikov North-Western State Medical University, Ministry of Health of Russia, Saint Petersburg, Russia
| | - D V Zaslavsky
- Saint Petersburg State Pediatric Medical University, Ministry of Health of Russia, Saint Petersburg, Russia
| | - R A Nasyrov
- Saint Petersburg State Pediatric Medical University, Ministry of Health of Russia, Saint Petersburg, Russia
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Kylmäoja E, Nakamura M, Kokkonen-Puuperä H, Ronkainen VP, Lehenkari P, Tuukkanen J. Gap junctional communication is involved in differentiation of osteoclasts from bone marrow and peripheral blood monocytes. Heliyon 2018; 4:e00621. [PMID: 29756076 PMCID: PMC5944415 DOI: 10.1016/j.heliyon.2018.e00621] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/05/2018] [Accepted: 05/02/2018] [Indexed: 12/22/2022] Open
Abstract
Aims The aim of the study was to compare the influence of gap junctional communication (GJC) in osteoclastogenesis from bone marrow (BM) and peripheral blood (PB) monocytes. These widely used sources differ in purity, since BM cultures contain a significant number of stromal cells. We studied whether stimulation of GJC in BM monocyte/stromal cell cultures differs from the effect in pure PB monocyte cultures. We compared the differentiation also in acidosis, which is a known inducer of bone resorption. Main methods Human BM and PB monocytes were isolated from BM aspirates or whole blood samples. The cells were cultured on human bone slices with osteoclastogenic growth factors and a GJC modulator, antiarrhythmic peptide AAP10, at physiological and acidic pH. Key findings Both BM and PB monocytes differentiated into osteoclasts. Acidosis increased resorption in both cultures but stimulated cell fusion only in BM cultures, which demonstrates the role of stromal cells in osteoclastogenesis. At physiological pH, AAP10 increased the number of multinuclear cells and bone resorption in both BM and PB cultures indicating that GJC is involved in differentiation in both of these osteoclastogenesis assays. Interestingly, in PB cultures at pH 6.5 the stimulation of GJC with AAP10 inhibited both osteoclastogenesis and bone resorption suggesting a different role of GJC in BM and PB monocytes at stressed environment. Significance The study is conducted with primary human tissue samples and adds new knowledge on factors affecting osteoclastogenesis from different monocyte sources.
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Affiliation(s)
- Elina Kylmäoja
- Institute of Cancer Research and Translational Medicine, Department of Anatomy and Cell Biology, Medical Research Center, P.O. Box 5000, 90014, University of Oulu, Finland
- Corresponding author.
| | - Miho Nakamura
- Institute of Cancer Research and Translational Medicine, Department of Anatomy and Cell Biology, Medical Research Center, P.O. Box 5000, 90014, University of Oulu, Finland
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 1010062, Japan
| | - Hanna Kokkonen-Puuperä
- Institute of Cancer Research and Translational Medicine, Department of Anatomy and Cell Biology, Medical Research Center, P.O. Box 5000, 90014, University of Oulu, Finland
| | - Veli-Pekka Ronkainen
- Biocenter Oulu, Light Microscopy Core Facility, P.O. Box 5000, 90014, University of Oulu, Finland
| | - Petri Lehenkari
- Institute of Cancer Research and Translational Medicine, Department of Anatomy and Cell Biology, Medical Research Center, P.O. Box 5000, 90014, University of Oulu, Finland
| | - Juha Tuukkanen
- Institute of Cancer Research and Translational Medicine, Department of Anatomy and Cell Biology, Medical Research Center, P.O. Box 5000, 90014, University of Oulu, Finland
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Connexin 43 and ATP-sensitive potassium channels crosstalk: a missing link in hypoxia/ischemia stress. Cell Tissue Res 2017; 371:213-222. [PMID: 29185069 DOI: 10.1007/s00441-017-2736-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 11/06/2017] [Indexed: 12/28/2022]
Abstract
Connexin 43 (Cx43) is a gap junction protein expressed in various tissues and organs of vertebrates. Besides functioning as a gap junction, Cx43 also regulates diverse cellular processes like cell growth and differentiation, cell migration, cell survival, etc. Cx43 is critical for normal cardiac functioning and is therefore abundantly expressed in cardiomyocytes. On the other hand, ATP-sensitive potassium (KATP) channels are metabolic sensors converting metabolic changes into electrical activity. These channels are important in maintaining the neurotransmitter release, smooth muscle relaxation, cardiac action potential repolarization, normal physiology of cellular repolarization, insulin secretion and immune function. Cx43 and KATP channels are part of the same signaling pathway, regulating cell survival during stress conditions and ischemia/hypoxia preconditioning. However, the underlying molecular mechanism for their combined role in ischemia/hypoxia preconditioning is largely unknown. The current review focuses on understanding the molecular mechanism responsible for the coordinated role of Cx43 and KATP channel protein in protecting cardiomyocytes against ischemia/hypoxia stress.
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Leybaert L, Lampe PD, Dhein S, Kwak BR, Ferdinandy P, Beyer EC, Laird DW, Naus CC, Green CR, Schulz R. Connexins in Cardiovascular and Neurovascular Health and Disease: Pharmacological Implications. Pharmacol Rev 2017; 69:396-478. [PMID: 28931622 PMCID: PMC5612248 DOI: 10.1124/pr.115.012062] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Connexins are ubiquitous channel forming proteins that assemble as plasma membrane hemichannels and as intercellular gap junction channels that directly connect cells. In the heart, gap junction channels electrically connect myocytes and specialized conductive tissues to coordinate the atrial and ventricular contraction/relaxation cycles and pump function. In blood vessels, these channels facilitate long-distance endothelial cell communication, synchronize smooth muscle cell contraction, and support endothelial-smooth muscle cell communication. In the central nervous system they form cellular syncytia and coordinate neural function. Gap junction channels are normally open and hemichannels are normally closed, but pathologic conditions may restrict gap junction communication and promote hemichannel opening, thereby disturbing a delicate cellular communication balance. Until recently, most connexin-targeting agents exhibited little specificity and several off-target effects. Recent work with peptide-based approaches has demonstrated improved specificity and opened avenues for a more rational approach toward independently modulating the function of gap junctions and hemichannels. We here review the role of connexins and their channels in cardiovascular and neurovascular health and disease, focusing on crucial regulatory aspects and identification of potential targets to modify their function. We conclude that peptide-based investigations have raised several new opportunities for interfering with connexins and their channels that may soon allow preservation of gap junction communication, inhibition of hemichannel opening, and mitigation of inflammatory signaling.
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Affiliation(s)
- Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Paul D Lampe
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Stefan Dhein
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Brenda R Kwak
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Peter Ferdinandy
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Eric C Beyer
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Dale W Laird
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Christian C Naus
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Colin R Green
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Rainer Schulz
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
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9
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Connexins and skin disease: insights into the role of beta connexins in skin homeostasis. Cell Tissue Res 2015; 360:645-58. [PMID: 25616557 DOI: 10.1007/s00441-014-2094-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/08/2014] [Indexed: 12/20/2022]
Abstract
Cell-to-cell communication triggered by connexin channels plays a central role in maintaining epidermal homeostasis. Here, we discuss the role of the beta connexin subgroup, where site-specific mutations in at least 4 of these proteins lead to distinctive non-inflammatory and inflammatory hyperproliferative epidermal disorders. Recent advances in the molecular pathways evoked and correlation with clinical outcome are discussed. The latest data provide increasing evidence that connexins in the epidermis are sensors to environmental stress and that targeting aberrant hemichannel activity holds significant therapeutic potential for inflammatory skin disorders.
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10
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Ni M, Ruan L, Zhang C. Antiarrhythmic Peptide AAP10 Prevents Arrhythmias Induced by Protein Kinase C Activation in Rabbit Left Ventricular Wedges. Int Heart J 2015; 56:234-8. [DOI: 10.1536/ihj.14-234] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Mingke Ni
- Department of Cardiology, Zhongshan Hospital
| | - Lei Ruan
- Department of Gerontology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology
| | - Cuntai Zhang
- Department of Gerontology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology
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11
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Iyyathurai J, D'hondt C, Wang N, De Bock M, Himpens B, Retamal MA, Stehberg J, Leybaert L, Bultynck G. Peptides and peptide-derived molecules targeting the intracellular domains of Cx43: gap junctions versus hemichannels. Neuropharmacology 2013; 75:491-505. [PMID: 23664811 DOI: 10.1016/j.neuropharm.2013.04.050] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 04/17/2013] [Accepted: 04/18/2013] [Indexed: 12/15/2022]
Abstract
About a decade ago, the molecular determinants controlling the opening and closing of Cx43 gap junction channels have been identified. Advanced biophysical approaches revealed a critical role for structural rearrangements in the cytoplasmic loop and dimerization of the C-terminal tail, resulting in binding of the C-terminal tail to the cytoplasmic loop and Cx43 gap junction channel closure during cellular acidosis. This has spurred the development of Cx43-mimetic peptides and peptidomimetics that interfere with these loop/tail interactions, thereby preventing the closure of Cx43 gap junctions, e.g. in the heart upon ischemia. Recently, we found that loop/tail interactions control Cx43-hemichannel activity but with an opposite effect. Binding of the C-terminal tail to the cytoplasmic loop is a requisite for the opening of Cx43 hemichannels in response to different stimuli, like decreased extracellular [Ca2+], increased intracellular [Ca2+], positive membrane potentials or ischemia. Strikingly, peptides that favor the open state of Cx43 gap junctions like the L2 peptide inhibit Cx43-hemichannel opening. These tools now provide unprecedented opportunities to selectively inhibit Cx43 hemichannels while maintaining Cx43 gap junction communication, impossible to achieve with siRNA or knockdown approaches both affecting gap junctions and hemichannels. These tools not only are very helpful to unravel the role of Cx43 hemichannels in complex biological systems, but also hold therapeutic potential to counteract excessive Cx43-hemichannel activity like in ischemia/reperfusion in the brain and the heart or to prevent Cx43 hemichannel-mediated gliotransmitter release in the basal amygdala during memory consolidation in response to emotional events. This article is part of the Special Issue Section entitled 'Current Pharmacology of Gap Junction Channels and Hemichannels'.
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Affiliation(s)
- Jegan Iyyathurai
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I Bus 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Catheleyne D'hondt
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I Bus 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Nan Wang
- Faculty of Medicine and Health Sciences, Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B-Rm 310), B-9000 Ghent, Belgium
| | - Marijke De Bock
- Faculty of Medicine and Health Sciences, Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B-Rm 310), B-9000 Ghent, Belgium
| | - Bernard Himpens
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I Bus 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Mauricio A Retamal
- Departamento de Fisiología, Facultad de Medicina, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile
| | - Jimmy Stehberg
- Universidad Andres Bello, Laboratorio de Neurobiologia, Departamento de Ciencias Biologicas, Facultad de Ciencias Biologicas & Facultad de Medicina, Santiago, Chile; Universidad Andres Bello, Centro de Investigaciones Biomédicas, Santiago, Chile
| | - Luc Leybaert
- Faculty of Medicine and Health Sciences, Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B-Rm 310), B-9000 Ghent, Belgium
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I Bus 802, Herestraat 49, BE-3000 Leuven, Belgium.
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12
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Cell motility in models of wounded human skin is improved by Gap27 despite raised glucose, insulin and IGFBP-5. Exp Cell Res 2012; 319:390-401. [PMID: 23262023 DOI: 10.1016/j.yexcr.2012.12.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 12/12/2012] [Accepted: 12/13/2012] [Indexed: 11/21/2022]
Abstract
Reducing Cx43 expression stimulates skin wound healing. This is mimicked in models when Cx43 function is blocked by the connexin mimetic peptide Gap27. IGF-I also stimulates wound healing with IGFBP-5 attenuating its actions. Further, the IGF-I to IGFBP-5 ratio is altered in diabetic skin, where wound closure is impaired. We investigated whether Gap27 remains effective in augmenting scrape-wound closure in human skin wound models simulating diabetes-induced changes, using culture conditions with raised glucose, insulin and IGFBP-5. Gap27 increased scrape-wound closure in normal glucose and insulin (NGI) and to a lesser extent in high glucose and insulin (HGI). IGF-I enhanced scrape-wound closure in keratinocytes whereas IGFBP-5 inhibited this response. Gap27 overcame the inhibitory effects of IGFBP-5 on IGF-I activity. Connexin-mediated communication (CMC) was reduced in HGI, despite raised Cx43, and Gap27 significantly decreased CMC in NGI and HGI. IGF-I and IGFBP-5 did not affect CMC. IGF-I increased keratinocyte proliferation in NGI, and Gap27 increased proliferation in NGI to a greater extent than in HGI. We conclude that IGF-I and Gap27 stimulate scrape-wound closure by independent mechanisms with Gap27 inhibiting Cx43 function. Gap27 can enhance wound closure in diabetic conditions, irrespective of the IGF-I:IGFBP-5 balance.
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13
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Donnelly S, English G, de Zwart-Storm EA, Lang S, van Steensel MAM, Martin PE. Differential susceptibility of Cx26 mutations associated with epidermal dysplasias to peptidoglycan derived from Staphylococcus aureus and Staphylococcus epidermidis. Exp Dermatol 2012; 21:592-8. [PMID: 22643125 DOI: 10.1111/j.1600-0625.2012.01521.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/27/2012] [Indexed: 12/28/2022]
Abstract
Mutations in Connexin26 (Cx26) give rise to a spectrum of dominantly inherited hyperproliferating skin disorders, the severest being keratitis-ichthyosis-deafness (KID) syndrome, an inflammatory skin disorder, with patients prone to opportunistic infections. We compared the effects of peptidoglycan (PGN) extracted from the skin commensal Staphylococcus epidermidis and the opportunistic pathogen Staphylococcus aureus on interleukin-6 and connexin expression in HaCaT cells (a keratinocyte cell line) and connexin channel activity in HaCaT and HeLa (connexin deficient) cells transfected to express KID and non-KID Cx26 mutations. In both cell types, PGN from S. aureus induced hemichannel activity in cells expressing KID mutants as monitored by ATP release assays following 15-min challenge, while that from S. epidermidis evoked a response in HeLa cells. In KID mutant expressing cells, ATP release was significantly higher than in cells transfected with wild-type Cx26. No ATP release was observed in non-KID mutant transfected cells or in the presence of carbenoxolone, a connexin channel blocker. PGN isolated from S. aureus but not S. epidermidis induced interleukin-6 and Cx26 expression in HaCaT cells following 6-h challenge. Challenge by PGN from S. aureus evoked a greater interleukin-6 response in cells expressing KID mutants than in cells expressing wtCx26 or non-KID mutants. This response returned to basal levels if acute KID hemichannel signalling was blocked prior to PGN challenge. Thus, KID mutants form channels that can be triggered by the pro-inflammatory mediator PGN from opportunistic pathogens but not skin commensals, providing further insight into the genotype-phenotype relationship of Cx26 disorders.
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Affiliation(s)
- Steven Donnelly
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Scotland, UK
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14
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Easton JA, Donnelly S, Kamps MAF, Steijlen PM, Martin PE, Tadini G, Janssens R, Happle R, van Geel M, van Steensel MAM. Porokeratotic eccrine nevus may be caused by somatic connexin26 mutations. J Invest Dermatol 2012; 132:2184-91. [PMID: 22592158 PMCID: PMC3422696 DOI: 10.1038/jid.2012.143] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Porokeratotic eccrine ostial and dermal duct nevus, or porokeratotic eccrine nevus (PEN), is a hyperkeratotic epidermal nevus. Several cases of widespread involvement have been reported, including one in association with the keratitis–ichthyosis–deafness (KID) syndrome (OMIM #148210), a rare disorder caused by mutations in the GJB2 gene coding for the gap junction protein connexin26 (Cx26). The molecular cause is, as yet, unknown. We have noted that PEN histopathology is shared by KID. The clinical appearance of PEN can resemble that of KID syndrome. Furthermore, a recent report of cutaneous mosaicism for a GJB2 mutation associated with KID describes linear hyperkeratotic skin lesions that might be consistent with PEN. From this, we hypothesized that PEN might be caused by Cx26 mutations associated with KID or similar gap junction disorders. Thus, we analyzed the GJB2 gene in skin samples from two patients referred with generalized PEN. In both, we found GJB2 mutations in the PEN lesions but not in unaffected skin or peripheral blood. One mutation was already known to cause the KID syndrome, and the other had not been previously associated with skin symptoms. We provide extensive functional data to support its pathogenicity. We conclude that PEN may be caused by mosaic GJB2 mutations.
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Affiliation(s)
- Jennifer A Easton
- Department of Dermatology, Maastricht University Medical Center, Maastricht, The Netherlands.
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15
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Abstract
The appearance of multicellular organisms imposed the development of several mechanisms for cell-to-cell communication, whereby different types of cells coordinate their function. Some of these mechanisms depend on the intercellular diffusion of signal molecules in the extracellular spaces, whereas others require cell-to-cell contact. Among the latter mechanisms, those provided by the proteins of the connexin family are widespread in most tissues. Connexin signaling is achieved via direct exchanges of cytosolic molecules between adjacent cells at gap junctions, for cell-to-cell coupling, and possibly also involves the formation of membrane "hemi-channels," for the extracellular release of cytosolic signals, direct interactions between connexins and other cell proteins, and coordinated influence on the expression of multiple genes. Connexin signaling appears to be an obligatory attribute of all multicellular exocrine and endocrine glands. Specifically, the experimental evidence we review here points to a direct participation of the Cx36 isoform in the function of the insulin-producing β-cells of the endocrine pancreas, and of the Cx40 isoform in the function of the renin-producing juxtaglomerular epithelioid cells of the kidney cortex.
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Affiliation(s)
- Domenico Bosco
- Department of Surgery, University of Geneva Medical School, Geneva, Switzerland
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16
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Peptidoglycan derived from Staphylococcus epidermidis induces Connexin43 hemichannel activity with consequences on the innate immune response in endothelial cells. Biochem J 2010; 432:133-43. [PMID: 20815816 DOI: 10.1042/bj20091753] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Gram-positive bacterial cell wall components including PGN (peptidoglycan) elicit a potent pro-inflammatory response in diverse cell types, including endothelial cells, by activating TLR2 (Toll-like receptor 2) signalling. The functional integrity of the endothelium is under the influence of a network of gap junction intercellular communication channels composed of Cxs (connexins) that also form hemichannels, signalling conduits that are implicated in ATP release and purinergic signalling. PGN modulates Cx expression in a variety of cell types, yet effects in endothelial cells remain unresolved. Using the endothelial cell line b.End5, a 6 h challenge with PGN induced IL-6 (interleukin 6), TLR2 and Cx43 mRNA expression that was associated with enhanced Cx43 protein expression and gap junction coupling. Cx43 hemichannel activity, measured by ATP release from the cells, was induced following 15 min of exposure to PGN. Inhibition of hemichannel activity with carbenoxolone or apyrase prevented induction of IL-6 and TLR2 mRNA expression by PGN, but had no effect on Cx43 mRNA expression levels. In contrast, knockdown of TLR2 expression had no effect on PGN-induced hemichannel activity, but reduced the level of TLR2 and Cx43 mRNA expression following 6 h of PGN challenge. PGN also acutely induced hemichannel activity in HeLa cells transfected to express Cx43, but had no effect in Cx43-deficient HeLa OHIO cells. All ATP responses were blocked with Cx-specific channel blockers. We conclude that acute Cx43 hemichannel signalling plays a role in the initiation of early innate immune responses in the endothelium.
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Li LD, Zhang CT, Ruan L, Ni MK, Quan XQ. Gap junctions enhancer combined with Vaughan Williams class III antiarrhythmic drugs, a promising antiarrhythmic method? Med Hypotheses 2010; 76:119-21. [PMID: 20889260 DOI: 10.1016/j.mehy.2010.08.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 08/24/2010] [Accepted: 08/27/2010] [Indexed: 11/18/2022]
Abstract
Arrhythmias is one of the leading causes of death in the world. Current antiarrhythmic drugs are limited by unsatisfactory efficacy and adverse effects such as proarrhythmias. Reentry mechanism plays an important role in persistence of arrhythmias. Reentry can only continue when reentry path-length is longer than cardiac wavelength which is equal to the product of conduction velocity (CV) and effective refractory period (ERP). Gap junctions uncoupling is associated with proarrhythmic CV slowing and transmural dispersion of repolarization (TDR) increasing in many cardiac diseases. Vaughan Williams class III antiarrhythmic drugs prolong ERP with an augmented TDR which is the main mechanism of the proarrhythmic effects. Gap junctions enhancer can augment CV and diminish TDR. As a result, gap junctions enhancer combined with class III drugs may be a promising antiarrhythmic method.
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Affiliation(s)
- Lian-dong Li
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China
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18
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Ravens U. Antiarrhythmic therapy in atrial fibrillation. Pharmacol Ther 2010; 128:129-45. [DOI: 10.1016/j.pharmthera.2010.06.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 06/11/2010] [Indexed: 12/19/2022]
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19
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Johnstone SR, Best AK, Wright CS, Isakson BE, Errington RJ, Martin PE. Enhanced connexin 43 expression delays intra-mitotic duration and cell cycle traverse independently of gap junction channel function. J Cell Biochem 2010; 110:772-82. [PMID: 20512937 DOI: 10.1002/jcb.22590] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Connexins (Cxs) and gap junction (GJ)-mediated communication have been linked with the regulation of cell cycle traverse. However, it is not clear whether Cx expression or GJ channel function are the key mediators in this process or at what stage this regulation may occur. We therefore tested the hypothesis that enhanced Cx expression could alter the rate of cell cycle traverse independently of GJ channel function. Sodium butyrate (NaBu) or anti-arrhythmic peptide (AAP10) were used to enhance Cx expression in HeLa cells stably expressing Cx43 (HeLa-43) and primary cultures of human fibroblasts (HFF) that predominantly express Cx43. To reduce GJ-mediated communication, 18-alpha-glycyrrhetinic acid (GA) was used. In HeLa-43 and HFF cells, NaBu and AAP10 enhanced Cx43 expression and increased channel function, while GA reduced GJ-mediated communication but did not significantly alter Cx43 expression levels. Timelapse microscopy and flow cytometry of HeLa-WT (wild-type, Cx deficient) and HeLa-43 cells dissected cell cycle traverse and enabled measurements of intra-mitotic time and determined levels of G1 arrest. Enhanced Cx43 expression increased mitotic durations corresponding with a G1 delay in cell cycle, which was linked to an increase in expression of the cell cycle inhibitor p21(waf1/cip1) in both HeLa-43 and HFF cells. Reductions in Cx43 channel function did not abrogate these responses, indicating that GJ channel function was not a critical factor in reducing cell proliferation in either cell type. We conclude that enhanced Cx43 expression and not GJ-mediated communication, is involved in regulating cell cycle traverse.
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Affiliation(s)
- Scott R Johnstone
- Department of Biological and Biomedical Sciences, School of Life Sciences, Glasgow Caledonian University, 70 Cowcaddens Rd, Glasgow, Scotland G4 0BA, UK
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20
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Novel pharmacological approaches for antiarrhythmic therapy. Naunyn Schmiedebergs Arch Pharmacol 2010; 381:187-93. [DOI: 10.1007/s00210-009-0487-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 12/17/2009] [Indexed: 01/14/2023]
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21
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Dhein S, Hagen A, Jozwiak J, Dietze A, Garbade J, Barten M, Kostelka M, Mohr FW. Improving cardiac gap junction communication as a new antiarrhythmic mechanism: the action of antiarrhythmic peptides. Naunyn Schmiedebergs Arch Pharmacol 2009; 381:221-34. [PMID: 19943035 DOI: 10.1007/s00210-009-0473-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Accepted: 11/08/2009] [Indexed: 12/22/2022]
Abstract
Co-ordinated electrical activation of the heart is maintained by intercellular coupling of cardiomyocytes via gap junctional channels located in the intercalated disks. These channels consist of two hexameric hemichannels, docked to each other, provided by either of the adjacent cells. Thus, a complete gap junction channel is made from 12 protein subunits, the connexins. While 21 isoforms of connexins are presently known, cardiomyocytes typically are coupled by Cx43 (most abundant), Cx40 or Cx45. Some years ago, antiarrhythmic peptides were discovered and synthesised, which were shown to increase macroscopic gap junction conductance (electrical coupling) and enhance dye transfer (metabolic coupling). The lead substance of these peptides is AAP10 (H-Gly-Ala-Gly-Hyp-Pro-Tyr-CONH(2)), a peptide with a horseshoe-like spatial structure as became evident from two-dimensional nuclear magnetic resonance studies. A stable D: -amino-acid derivative of AAP10, rotigaptide, as well as a non-peptide analogue, gap-134, has been developed in recent years. Antiarrhythmic peptides act on Cx43 and Cx45 gap junctions but not on Cx40 channels. AAP10 has been shown to enhance intercellular communication in rat, rabbit and human cardiomyocytes. Antiarrhythmic peptides are effective against ventricular tachyarrhythmias, such as late ischaemic (type IB) ventricular fibrillation, CaCl(2) or aconitine-induced arrhythmia. Interestingly, the effect of antiarrhythmic peptides is higher in partially uncoupled cells and was shown to be related to maintained Cx43 phosphorylation, while arrhythmogenic conditions like ischaemia result in Cx43 dephosphorylation and intercellular decoupling. It is still a matter of debate whether these drugs also act against atrial fibrillation. The present review outlines the development of this group of peptides and derivatives, their mode of action and molecular mechanisms, and discusses their possible therapeutic potential.
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Affiliation(s)
- Stefan Dhein
- Clinic for Cardiac Surgery, University of Leipzig, Struempellstr. 39, 04289, Leipzig, Germany.
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