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Yasarbas SS, Inal E, Yildirim MA, Dubrac S, Lamartine J, Mese G. Connexins in epidermal health and diseases: insights into their mutations, implications, and therapeutic solutions. Front Physiol 2024; 15:1346971. [PMID: 38827992 PMCID: PMC11140265 DOI: 10.3389/fphys.2024.1346971] [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: 11/30/2023] [Accepted: 04/15/2024] [Indexed: 06/05/2024] Open
Abstract
The epidermis, the outermost layer of the skin, serves as a protective barrier against external factors. Epidermal differentiation, a tightly regulated process essential for epidermal homeostasis, epidermal barrier formation and skin integrity maintenance, is orchestrated by several players, including signaling molecules, calcium gradient and junctional complexes such as gap junctions (GJs). GJ proteins, known as connexins facilitate cell-to-cell communication between adjacent keratinocytes. Connexins can function as either hemichannels or GJs, depending on their interaction with other connexons from neighboring keratinocytes. These channels enable the transport of metabolites, cAMP, microRNAs, and ions, including Ca2+, across cell membranes. At least ten distinct connexins are expressed within the epidermis and mutations in at least five of them has been linked to various skin disorders. Connexin mutations may cause aberrant channel activity by altering their synthesis, their gating properties, their intracellular trafficking, and the assembly of hemichannels and GJ channels. In addition to mutations, connexin expression is dysregulated in other skin conditions including psoriasis, chronic wound and skin cancers, indicating the crucial role of connexins in skin homeostasis. Current treatment options for conditions with mutant or altered connexins are limited and primarily focus on symptom management. Several therapeutics, including non-peptide chemicals, antibodies, mimetic peptides and allele-specific small interfering RNAs are promising in treating connexin-related skin disorders. Since connexins play crucial roles in maintaining epidermal homeostasis as shown with linkage to a range of skin disorders and cancer, further investigations are warranted to decipher the molecular and cellular alterations within cells due to mutations or altered expression, leading to abnormal proliferation and differentiation. This would also help characterize the roles of each isoform in skin homeostasis, in addition to the development of innovative therapeutic interventions. This review highlights the critical functions of connexins in the epidermis and the association between connexins and skin disorders, and discusses potential therapeutic options.
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Affiliation(s)
- S. Suheda Yasarbas
- Izmir Institute of Technology, Faculty of Science, Department of Molecular Biology and Genetics, Izmir, Turkiye
| | - Ece Inal
- Izmir Institute of Technology, Faculty of Science, Department of Molecular Biology and Genetics, Izmir, Turkiye
| | - M. Azra Yildirim
- Izmir Institute of Technology, Faculty of Science, Department of Molecular Biology and Genetics, Izmir, Turkiye
| | - Sandrine Dubrac
- Department of Dermatology, Venereology and Allergology, Medical University of Innsbruck, Innsbruck, Austria
| | - Jérôme Lamartine
- Skin Functional Integrity Group, Laboratory for Tissue Biology and Therapeutics Engineering (LBTI) CNRS UMR5305, University of Lyon, Lyon, France
| | - Gulistan Mese
- Izmir Institute of Technology, Faculty of Science, Department of Molecular Biology and Genetics, Izmir, Turkiye
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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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Phang SJ, Arumugam B, Kuppusamy UR, Fauzi MB, Looi ML. A review of diabetic wound models-Novel insights into diabetic foot ulcer. J Tissue Eng Regen Med 2021; 15:1051-1068. [PMID: 34551455 DOI: 10.1002/term.3246] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 08/06/2021] [Accepted: 09/17/2021] [Indexed: 12/13/2022]
Abstract
Diabetic foot ulcer (DFU) is a major debilitating complication of diabetes. Many research investigations have been conducted with the aims to uncover the diabetic wound healing mechanisms, develop novel therapeutics, and screen bioactive wound dressings in order to improve the current management of DFU. These would have not been possible without the utilization of an appropriate wound model, especially in a diabetic wound context. This review focuses on the different in vitro research models used in DFU investigations such as the 2D scratch wound assay, 3D skin model, and 3D angiogenesis model as well as their limitations. The current efforts and challenges to apply the 2D and 3D in vitro models in a hyperglycemic context to provide insights into DFU modeling will be reviewed. Perspectives of utilizing 3D bioprinting and skin-on-the-chip model as a diabetic wound model in the future will also be highlighted. By leveraging knowledge from past experiences and current research, an improved experimental model for DFU is anticipated to be established in near future.
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Affiliation(s)
- Shou Jin Phang
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Bavani Arumugam
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Umah Rani Kuppusamy
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Mh Busra Fauzi
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Mee Lee Looi
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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O’Shaughnessy EM, Duffy W, Garcia-Vega L, Hussey K, Burden AD, Zamiri M, Martin PE. Dysregulation of Connexin Expression Plays a Pivotal Role in Psoriasis. Int J Mol Sci 2021; 22:ijms22116060. [PMID: 34199748 PMCID: PMC8200029 DOI: 10.3390/ijms22116060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/28/2021] [Accepted: 06/01/2021] [Indexed: 12/13/2022] Open
Abstract
Background: Psoriasis, a chronic inflammatory disease affecting 2–3% of the population, is characterised by epidermal hyperplasia, a sustained pro-inflammatory immune response and is primarily a T-cell driven disease. Previous work determined that Connexin26 is upregulated in psoriatic tissue. This study extends these findings. Methods: Biopsies spanning psoriatic plaque (PP) and non-involved tissue (PN) were compared to normal controls (NN). RNA was isolated and subject to real-time PCR to determine gene expression profiles, including GJB2/CX26, GJB6/CX30 and GJA1/CX43. Protein expression was assessed by immunohistochemistry. Keratinocytes and fibroblasts were isolated and used in 3D organotypic models. The pro-inflammatory status of fibroblasts and 3D cultures was assessed via ELISA and RnD cytokine arrays in the presence or absence of the connexin channel blocker Gap27. Results: Connexin26 expression is dramatically enhanced at both transcriptional and translational level in PP and PN tissue compared to NN (>100x). In contrast, CX43 gene expression is not affected, but the protein is post-translationally modified and accumulates in psoriatic tissue. Fibroblasts isolated from psoriatic patients had a higher inflammatory index than normal fibroblasts and drove normal keratinocytes to adopt a “psoriatic phenotype” in a 3D-organotypic model. Exposure of normal fibroblasts to the pro-inflammatory mediator peptidoglycan, isolated from Staphylococcus aureus enhanced cytokine release, an event protected by Gap27. Conclusion: dysregulation of the connexin26:43 expression profile in psoriatic tissue contributes to an imbalance of cellular events. Inhibition of connexin signalling reduces pro-inflammatory events and may hold therapeutic benefit.
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Affiliation(s)
- Erin M. O’Shaughnessy
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK; (E.M.O.); (L.G.-V.)
| | - William Duffy
- Department of Dermatology, University Hospital Crosshouse, Kilmarnock KA2 0BE, UK; (W.D.); (M.Z.)
| | - Laura Garcia-Vega
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK; (E.M.O.); (L.G.-V.)
| | - Keith Hussey
- Department of Vascular Surgery, Queen Elizabeth University Hospital, Glasgow G51 4TF, UK;
| | - A. David Burden
- Institute of Infection Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK;
| | - Mozheh Zamiri
- Department of Dermatology, University Hospital Crosshouse, Kilmarnock KA2 0BE, UK; (W.D.); (M.Z.)
- Department of Dermatology, Queen Elizabeth University Hospital, Glasgow G51 4TF, UK
| | - Patricia E. Martin
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK; (E.M.O.); (L.G.-V.)
- Correspondence: ; Tel.: +44-141-331-3726
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Flores-Muñoz C, Maripillán J, Vásquez-Navarrete J, Novoa-Molina J, Ceriani R, Sánchez HA, Abbott AC, Weinstein-Oppenheimer C, Brown DI, Cárdenas AM, García IE, Martínez AD. Restraint of Human Skin Fibroblast Motility, Migration, and Cell Surface Actin Dynamics, by Pannexin 1 and P2X7 Receptor Signaling. Int J Mol Sci 2021; 22:1069. [PMID: 33499026 PMCID: PMC7865282 DOI: 10.3390/ijms22031069] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 01/01/2023] Open
Abstract
Wound healing is a dynamic process required to maintain skin integrity and which relies on the precise migration of different cell types. A key molecule that regulates this process is ATP. However, the mechanisms involved in extracellular ATP management are poorly understood, particularly in the human dermis. Here, we explore the role, in human fibroblast migration during wound healing, of Pannexin 1 channels and their relationship with purinergic signals and in vivo cell surface filamentous actin dynamics. Using siRNA against Panx isoforms and different Panx1 channel inhibitors, we demonstrate in cultured human dermal fibroblasts that the absence or inhibition of Panx1 channels accelerates cell migration, increases single-cell motility, and promotes actin redistribution. These changes occur through a mechanism that involves the release of ATP to the extracellular space through a Panx1-dependent mechanism and the activation of the purinergic receptor P2X7. Together, these findings point to a pivotal role of Panx1 channels in skin fibroblast migration and suggest that these channels could be a useful pharmacological target to promote damaged skin healing.
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Affiliation(s)
- Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Jaime Maripillán
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Jacqueline Vásquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Joel Novoa-Molina
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Ricardo Ceriani
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Helmuth A. Sánchez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Ana C. Abbott
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Caroline Weinstein-Oppenheimer
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile;
- Centro de Investigación Farmacopea Chilena, Valparaíso 2360102, Chile
| | - Donald I. Brown
- Laboratorio de Biología de la Reproducción y del Desarrollo, Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile;
| | - Ana María Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Isaac E. García
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
- Laboratorio de Fisiología Molecular y Biofísica, Facultad de Odontología, Universidad de Valparaíso, Valparaíso 2360004, Chile
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
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McNair AJ, Wilson KS, Martin PE, Welsh DJ, Dempsie Y. Connexin 43 plays a role in proliferation and migration of pulmonary arterial fibroblasts in response to hypoxia. Pulm Circ 2020; 10:2045894020937134. [PMID: 32670564 PMCID: PMC7338651 DOI: 10.1177/2045894020937134] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 06/01/2020] [Indexed: 02/06/2023] Open
Abstract
Pulmonary hypertension (PH) is a disease associated with vasoconstriction and remodelling of the pulmonary vasculature. Pulmonary artery fibroblasts (PAFs) play an important role in hypoxic-induced remodelling. Connexin 43 (Cx43) is involved in cellular communication and regulation of the pulmonary vasculature. Using both in vitro and in vivo models of PH, the aims of this study were to (i) investigate the role of Cx43 in hypoxic-induced proliferation and migration of rat PAFs (rPAFs) and rat pulmonary artery smooth muscle cells (rPASMCs) and (ii) determine whether Cx43 expression is dysregulated in the rat sugen5416/hypoxic model of PH. The role of Cx43 in hypoxic-induced proliferation and migration was investigated using Gap27 (a pharmacological inhibitor of Cx43) or genetic knockdown of Cx43 using siRNA. Cx43 protein expression was increased by hypoxia in rPAFs but not rPASMCs. Hypoxic exposure, in the presence of serum, resulted in an increase in proliferation of rPAFs but not rPASMCs. Hypoxic exposure caused migration of rPAFs but not rPASMCs. Phosphorylation of p38 mitogen-activated protein kinase (MAPK) and ERK1/2 were increased by hypoxia in rPAFs. The effects of hypoxia on proliferation, migration and MAPK phosphorylation in rPAFs were attenuated in the presence of Gap27 or Cx43 siRNA. Cx43 protein expression was increased in sugen5416/hypoxic rat lung; this increased expression was not observed in sugen5416/hypoxic rats treated with the MAPK pathway inhibitor GS-444217. In conclusion, Cx43 is involved in the proliferation and migration of rPAFs in response to hypoxia via the MAPK signalling pathway.
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Affiliation(s)
- Andrew J McNair
- Department of Biological and Biomedical Science, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Kathryn S Wilson
- Department of Biological and Biomedical Science, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Patricia E Martin
- Department of Biological and Biomedical Science, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - David J Welsh
- Department of Biological and Biomedical Science, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK.,Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Yvonne Dempsie
- Department of Biological and Biomedical Science, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
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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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Greco S, Islam MS, Zannotti A, Delli Carpini G, Giannubilo SR, Ciavattini A, Petraglia F, Ciarmela P. Quercetin and indole-3-carbinol inhibit extracellular matrix expression in human primary uterine leiomyoma cells. Reprod Biomed Online 2020; 40:593-602. [PMID: 32276890 DOI: 10.1016/j.rbmo.2020.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 12/19/2019] [Accepted: 01/10/2020] [Indexed: 01/03/2023]
Abstract
RESEARCH QUESTION What is the effect of quercetin and indole-3-carbinol (I3C) on extracellular matrix expression, cell migration and proliferation in human myometrial and uterine leiomyoma cells. DESIGN Myometrial and leiomyoma cells were treated with quercetin or I3C at different concentrations (10 µg/ml; 50 µg/ml; 100 µg/ml; and 250 µg/ml) for 48 h to measure mRNA and protein expressions of extracellular matrix (collagen 1A1, fibronectin and versican), as well as cell migration and the proliferation rate. RESULTS Quercetin decreased mRNA levels of collagen 1A1 in myometrial (P < 0.0001) and leiomyoma cells (P < 0.0001). Quercetin reduced mRNA and protein levels of fibronectin in myometrial cells (P < 0.05) and fibronectin protein in leiomyoma cells (P < 0.05). I3C reduced collagen 1A1 mRNA levels in myometrial (P < 0.05) and leiomyoma cells at higher dose (P < 0.05). The protein levels of fibronectin were also reduced in both myometrial and leiomyoma cells with highest dose of I3C (P < 0.05), although mRNA levels were not affected in leiomyoma cells. Neither quercetin nor I3C treatment altered versican mRNA levels in both cell types. A significant reduction of the migration of both myometrial and leiomyoma cells in response to quercetin was observed (P < 0.05) and I3C (P < 0.05 for myometrial and P < 0.01 for leiomyoma cells) treatment. Both quercetin and I3C significantly reduced myometrial cell proliferation (P < 0.05). CONCLUSIONS The in-vitro anti-fibrotic, anti-migratory and anti-proliferative effects of quercetin and I3C form the scientific basis for developing new therapeutic, preventive agents, or both, for uterine leiomyomas.
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Affiliation(s)
- Stefania Greco
- Department of Experimental and Clinical Medicine, Faculty of Medicine, Università Politecnica delle Marche, 60020 via Tronto 10/a Ancona, Italy
| | - Md Soriful Islam
- Department of Experimental and Clinical Medicine, Faculty of Medicine, Università Politecnica delle Marche, 60020 via Tronto 10/a Ancona, Italy
| | - Alessandro Zannotti
- Department of Experimental and Clinical Medicine, Faculty of Medicine, Università Politecnica delle Marche, 60020 via Tronto 10/a Ancona, Italy; Department of Medical Biotechnology and Department of Molecular and Developmental, Medicine, Obstetrics, and Gynaecology, Università Politecnica delle Marche, Ancona 60020, Italy
| | - Giovanni Delli Carpini
- Department of Medical Biotechnology and Department of Molecular and Developmental, Medicine, Obstetrics, and Gynaecology, Università Politecnica delle Marche, Ancona 60020, Italy
| | - Stefano Raffaele Giannubilo
- Department of Medical Biotechnology and Department of Molecular and Developmental, Medicine, Obstetrics, and Gynaecology, Università Politecnica delle Marche, Ancona 60020, Italy
| | - Andrea Ciavattini
- Department of Medical Biotechnology and Department of Molecular and Developmental, Medicine, Obstetrics, and Gynaecology, Università Politecnica delle Marche, Ancona 60020, Italy
| | - Felice Petraglia
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", Obstetrics and Gynaecology, University of Florence, Italy
| | - Pasquapina Ciarmela
- Department of Experimental and Clinical Medicine, Faculty of Medicine, Università Politecnica delle Marche, 60020 via Tronto 10/a Ancona, Italy.
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Elbadawy HM, Elshawarby A, Raafat MH, Bahaa N, Abdul MIM, Aljuhani N, Bahashwan S, Eltahir HM, Albarry M, Parekh M, Ferrari S. Blocking connexin 43 accelerates corneal healing and improves tissue remodeling during the healing of diabetic rat corneas: A histological and immunohistochemical study. EUR J INFLAMM 2019. [DOI: 10.1177/2058739219843389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Connexin 43 (Cx43) is a potential target for accelerating wound healing. This study aimed at evaluating the therapeutic efficiency of topical application of Gap27, a Cx43 mimetic peptide, on corneal tissue reorganization during wound healing in streptozocin-induced Diabetes in albino rats and its effect on the infiltration of inflammatory cells. Fifty adult male albino Wistar rats were divided equally into two groups: non-diabetic and diabetic. Twenty rats from each group were subjected to corneal injury: 10 untreated and 10 treated with Gap27. The remaining five rats from each group served as negative controls (intact corneas). All rats were sacrificed 3 days after injury. Histological studies were performed to assess signs of cell degeneration, the infiltration of inflammatory cells. Histomorphometric studies were performed to quantify the expression of Cx43. Gap27 promoted corneal wound healing in non-diabetic and diabetic rats. It reduced mononuclear cell infiltration and improved corneal tissue remodeling. However, minor structural changes were still seen in diabetic corneas after treatment with Gap27. Blocking Cx43 was a valuable tool to restore corneal tissue structure, reduce the infiltration of inflammatory cells in non-diabetic and diabetic rats.
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Affiliation(s)
- Hossein M Elbadawy
- Department of Pharmacology and Toxicology, College of Pharmacy, Taibah University, Medina, Saudi Arabia
| | - Amany Elshawarby
- Department of Histology and Cell Biology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Mona H Raafat
- Department of Histology and Cell Biology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Nevine Bahaa
- Department of Histology and Cell Biology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Mohi IM Abdul
- Department of Pharmacology and Toxicology, College of Pharmacy, Taibah University, Medina, Saudi Arabia
| | - Naif Aljuhani
- Department of Pharmacology and Toxicology, College of Pharmacy, Taibah University, Medina, Saudi Arabia
| | - Saleh Bahashwan
- Department of Pharmacology and Toxicology, College of Pharmacy, Taibah University, Medina, Saudi Arabia
| | - Heba M Eltahir
- Department of Pharmacology and Toxicology, College of Pharmacy, Taibah University, Medina, Saudi Arabia
| | - Maan Albarry
- Department of Ophthalmology, College of Medicine, Taibah University, Medina, Saudi Arabia
| | - Mohit Parekh
- Institute of Ophthalmology, University College London, London, UK
| | - Stefano Ferrari
- International Center for Ocular Physiopathology, The Veneto Eye Bank Foundation, Venice, Italy
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10
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Sera T, Arai M, Cui Z, Onose K, Karimi A, Kudo S. Unloading of intercellular tension induces the directional translocation of PKCα. J Cell Physiol 2018; 234:9764-9777. [PMID: 30387146 DOI: 10.1002/jcp.27662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/02/2018] [Indexed: 12/13/2022]
Abstract
The migration of endothelial cells (ECs) is closely associated with a Ca2+ -dependent protein, protein kinase Cα (PKCα). The disruption of intercellular adhesion by single-cell wounding has been shown to induce the directional translocation of PKCα. We hypothesized that this translocation of PKCα is induced by mechanical stress, such as unloading of intercellular tension, or by intercellular communication, such as gap junction-mediated and paracrine signaling. In the current study, we found that the disruption of intercellular adhesion induced the directional translocation of PKCα even when gap junction-mediated and paracrine signaling were inhibited. Conversely, it did not occur when the mechanosensitive channel was inhibited. In addition, the strain field of substrate attributable to the disruption of intercellular adhesion tended to be larger at the areas corresponding with PKCα translocation. Recently, we found that a direct mechanical stimulus induced the accumulation of PKCα at the stimulus area, involving Ca 2+ influx from extracellular space. These results indicated that the unloading of intercellular tension induced directional translocation of PKCα, which required Ca 2+ influx from extracellular space. The results of this study indicate the involvement of PKCα in the Ca 2+ signaling pathway in response to mechanical stress in ECs.
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Affiliation(s)
- Toshihiro Sera
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Masataka Arai
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Zhonghua Cui
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Koichi Onose
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Alireza Karimi
- International Research Fellow, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Susumu Kudo
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
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11
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Regulation of connexin 43 expression in human gingival fibroblasts. Exp Cell Res 2018; 371:238-249. [PMID: 30118696 DOI: 10.1016/j.yexcr.2018.08.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/31/2018] [Accepted: 08/13/2018] [Indexed: 12/22/2022]
Abstract
AIMS Abundance of connexin 43 (Cx43), a transmembrane protein that forms hemichannels (HCs) and gap junctions (GJs), is dynamically regulated in human gingival fibroblasts (GFBLs) during wound healing. This may be important for fast and scarless gingival wound healing as Cx43 is involved in key cell functions important during this process. Our aim was to uncover the factors that regulate Cx43 expression and abundance in GFBLs. We hypothesized that cytokines and growth factors released during wound healing coordinately regulate Cx43 abundance in GFBLs. RESULTS TGF-β1, -β2, -β3, PGE2 and IL-1β significantly upregulated, while TNF-α and IFN-γ downregulated Cx43 in cultured GFBLs. TGF-β1, -β2, -β3, IL-1β and IFN-γ modulated Cx43 abundance at both mRNA and protein levels, while TNF-α and PGE2 regulated only Cx43 protein abundance, suggesting involvement of distinct transcriptional/post-transcriptional and translational/post-translational mechanisms, respectively. TGF-β1-induced upregulation of Cx43 was mediated by TGFβRI (ALK5) and SMAD2/3 signaling, and this was potently suppressed by PGE2, IL-1β, TNF-α and IFN-γ that inhibited SMAD2/3 phosphorylation. CONCLUSION Regulation of Cx43 abundance in GFBLs involves transcriptional/post-transcriptional and translational/post-translational mechanisms that are distinctly modulated by an interplay between TGF-β isoforms and PGE2, IL-1β, TNF-α and IFN-γ.
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12
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The potential of human induced pluripotent stem cells for modelling diabetic wound healing in vitro. Clin Sci (Lond) 2018; 132:1629-1643. [PMID: 30108152 DOI: 10.1042/cs20171483] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/28/2018] [Accepted: 07/23/2018] [Indexed: 12/11/2022]
Abstract
Impaired wound healing and ulceration caused by diabetes mellitus, is a significant healthcare burden, markedly impairs quality of life for patients, and is the major cause of amputation worldwide. Current experimental approaches used to investigate the complex wound healing process often involve cultures of fibroblasts and/or keratinocytes in vitro, which can be limited in terms of complexity and capacity, or utilisation of rodent models in which the mechanisms of wound repair differ substantively from that in humans. However, advances in tissue engineering, and the discovery of strategies to reprogramme adult somatic cells to pluripotency, has led to the possibility of developing models of human skin on a large scale. Generation of induced pluripotent stem cells (iPSCs) from tissues donated by diabetic patients allows the (epi)genetic background of this disease to be studied, and the ability to differentiate iPSCs to multiple cell types found within skin may facilitate the development of more complex skin models; these advances offer key opportunities for improving modelling of wound healing in diabetes, and the development of effective therapeutics for treatment of chronic wounds.
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13
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Htet M, Nally JE, Shaw A, Foote BE, Martin PE, Dempsie Y. Connexin 43 Plays a Role in Pulmonary Vascular Reactivity in Mice. Int J Mol Sci 2018; 19:E1891. [PMID: 29954114 PMCID: PMC6073802 DOI: 10.3390/ijms19071891] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/07/2018] [Accepted: 06/20/2018] [Indexed: 11/25/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a chronic condition characterized by vascular remodeling and increased vaso-reactivity. PAH is more common in females than in males (~3:1). Connexin (Cx)43 has been shown to be involved in cellular communication within the pulmonary vasculature. Therefore, we investigated the role of Cx43 in pulmonary vascular reactivity using Cx43 heterozygous (Cx43+/−) mice and 37,43Gap27, which is a pharmacological inhibitor of Cx37 and Cx43. Contraction and relaxation responses were studied in intra-lobar pulmonary arteries (IPAs) derived from normoxic mice and hypoxic mice using wire myography. IPAs from male Cx43+/− mice displayed a small but significant increase in the contractile response to endothelin-1 (but not 5-hydroxytryptamine) under both normoxic and hypoxic conditions. There was no difference in the contractile response to endothelin-1 (ET-1) or 5-hydroxytryptamine (5-HT) in IPAs derived from female Cx43+/−mice compared to wildtype mice. Relaxation responses to methacholine (MCh) were attenuated in IPAs from male and female Cx43+/− mice or by pre-incubation of IPAs with 37,43Gap27. Nω-Nitro-L-arginine methyl ester (l-NAME) fully inhibited MCh-induced relaxation. In conclusion, Cx43 is involved in nitric oxide (NO)-induced pulmonary vascular relaxation and plays a gender-specific and agonist-specific role in pulmonary vascular contractility. Therefore, reduced Cx43 signaling may contribute to pulmonary vascular dysfunction.
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Affiliation(s)
- Myo Htet
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Jane E Nally
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Andrew Shaw
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Bradley E Foote
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Patricia E Martin
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Yvonne Dempsie
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
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14
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Chanson M, Watanabe M, O'Shaughnessy EM, Zoso A, Martin PE. Connexin Communication Compartments and Wound Repair in Epithelial Tissue. Int J Mol Sci 2018; 19:ijms19051354. [PMID: 29751558 PMCID: PMC5983803 DOI: 10.3390/ijms19051354] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 12/20/2022] Open
Abstract
Epithelial tissues line the lumen of tracts and ducts connecting to the external environment. They are critical in forming an interface between the internal and external environment and, following assault from environmental factors and pathogens, they must rapidly repair to maintain cellular homeostasis. These tissue networks, that range from a single cell layer, such as in airway epithelium, to highly stratified and differentiated epithelial surfaces, such as the epidermis, are held together by a junctional nexus of proteins including adherens, tight and gap junctions, often forming unique and localised communication compartments activated for localised tissue repair. This review focuses on the dynamic changes that occur in connexins, the constituent proteins of the intercellular gap junction channel, during wound-healing processes and in localised inflammation, with an emphasis on the lung and skin. Current developments in targeting connexins as corrective therapies to improve wound closure and resolve localised inflammation are also discussed. Finally, we consider the emergence of the zebrafish as a concerted whole-animal model to study, visualise and track the events of wound repair and regeneration in real-time living model systems.
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Affiliation(s)
- Marc Chanson
- Department of Pediatrics and Cell Physiology & Metabolism, Geneva University Hospitals and University of Geneva, 1211 Geneva, Switzerland.
| | - Masakatsu Watanabe
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan.
| | - Erin M O'Shaughnessy
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Alice Zoso
- Department of Pediatrics and Cell Physiology & Metabolism, Geneva University Hospitals and University of Geneva, 1211 Geneva, Switzerland.
| | - Patricia E Martin
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
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15
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Connexin 43 regulates the expression of wound healing-related genes in human gingival and skin fibroblasts. Exp Cell Res 2018; 367:150-161. [PMID: 29596891 DOI: 10.1016/j.yexcr.2018.03.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/23/2018] [Accepted: 03/24/2018] [Indexed: 12/21/2022]
Abstract
Fibroblasts are the most abundant connective tissue cells and play an important role in wound healing. It is possible that faster and scarless wound healing in oral mucosal gingiva relative to skin may relate to the distinct phenotype of the fibroblasts residing in these tissues. Connexin 43 (Cx43) is the most ubiquitous Cx in skin (SFBLs) and gingival fibroblasts (GFBLs), and assembles into hemichannels (HCs) and gap junctions (GJs) on the cell membrane. We hypothesized that SFBLs and GFBLs display distinct expression or function of Cx43, and that this may partly underlie the different wound healing outcomes in skin and gingiva. Here we show that Cx43 distinctly formed Cx43 GJs and HCs in human skin and gingiva in vivo. However, in SFBLs, in contrast to GFBLs, only a small proportion of total Cx43 assembled into HC plaques. Using an in vivo-like 3D culture model, we further show that the GJ, HC, and channel-independent functions of Cx43 distinctly regulated wound healing-related gene expression in GFBLs and SFBLs. Therefore, the distinct wound healing outcomes in skin and gingiva may partly relate to the inherently different assembly and function of Cx43 in the resident fibroblasts.
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16
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Johnson RD, Camelliti P. Role of Non-Myocyte Gap Junctions and Connexin Hemichannels in Cardiovascular Health and Disease: Novel Therapeutic Targets? Int J Mol Sci 2018; 19:ijms19030866. [PMID: 29543751 PMCID: PMC5877727 DOI: 10.3390/ijms19030866] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 03/10/2018] [Accepted: 03/12/2018] [Indexed: 12/24/2022] Open
Abstract
The heart is a complex organ composed of multiple cell types, including cardiomyocytes and different non-myocyte populations, all working closely together to determine the hearts properties and maintain normal cardiac function. Connexins are abundantly expressed proteins that form plasma membrane hemichannels and gap junctions between cells. Gap junctions are intracellular channels that allow for communication between cells, and in the heart they play a crucial role in cardiac conduction by coupling adjacent cardiomyocytes. Connexins are expressed in both cardiomyocytes and non-myocytes, including cardiac fibroblasts, endothelial cells, and macrophages. Non-myocytes are the largest population of cells in the heart, and therefore it is important to consider what roles connexins, hemichannels, and gap junctions play in these cell types. The aim of this review is to provide insight into connexin-based signalling in non-myocytes during health and disease, and highlight how targeting these proteins could lead to the development of novel therapies. We conclude that connexins in non-myocytes contribute to arrhythmias and adverse ventricular remodelling following myocardial infarction, and are associated with the initiation and development of atherosclerosis. Therefore, therapeutic interventions targeting these connexins represent an exciting new research avenue with great potential.
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Affiliation(s)
- Robert D Johnson
- School of Biosciences and Medicine, University of Surrey, Guildford GU2 7XH, UK.
| | - Patrizia Camelliti
- School of Biosciences and Medicine, University of Surrey, Guildford GU2 7XH, UK.
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17
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Faniku C, O'Shaughnessy E, Lorraine C, Johnstone SR, Graham A, Greenhough S, Martin PEM. The Connexin Mimetic Peptide Gap27 and Cx43-Knockdown Reveal Differential Roles for Connexin43 in Wound Closure Events in Skin Model Systems. Int J Mol Sci 2018; 19:ijms19020604. [PMID: 29463027 PMCID: PMC5855826 DOI: 10.3390/ijms19020604] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/07/2018] [Accepted: 02/09/2018] [Indexed: 12/23/2022] Open
Abstract
In the epidermis, remodelling of Connexin43 is a key event in wound closure. However, controversy between the role of connexin channel and non-channel functions exist. We compared the impact of SiRNA targeted to Connexin43 and the connexin mimetic peptide Gap27 on scrape wound closure rates and hemichannel signalling in adult keratinocytes (AK) and fibroblasts sourced from juvenile foreskin (JFF), human neonatal fibroblasts (HNDF) and adult dermal tissue (ADF). The impact of these agents, following 24 h exposure, on GJA1 (encoding Connexin43), Ki67 and TGF-β1 gene expression, and Connexin43 and pSmad3 protein expression levels, were examined by qPCR and Western Blot respectively. In all cell types Gap27 (100 nM–100 μM) attenuated hemichannel activity. In AK and JFF cells, Gap27 (100 nM–100 μM) enhanced scrape wound closure rates by ~50% but did not influence movement in HNDF or ADF cells. In both JF and AK cells, exposure to Gap27 for 24 h reduced the level of Cx43 protein expression but did not affect the level in ADF and HNDF cells. Connexin43-SiRNA enhanced scrape wound closure in all the cell types under investigation. In HDNF and ADF, Connexin43-SiRNA enhanced cell proliferation rates, with enhanced proliferation also observed following exposure of HDNF to Gap27. By contrast, in JFF and AK cells no changes in proliferation occurred. In JFF cells, Connexin43-SiRNA enhanced TGF-β1 levels and in JFF and ADF cells both Connexin43-SiRNA and Gap27 enhanced pSmad3 protein expression levels. We conclude that Connexin43 signalling plays an important role in cell migration in keratinocytes and foreskin derived fibroblasts, however, different pathways are evoked and in dermal derived adult and neonatal fibroblasts, inhibition of Connexin43 signalling plays a more significant role in regulating cell proliferation than cell migration.
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Affiliation(s)
- Chrysovalantou Faniku
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Erin O'Shaughnessy
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Claire Lorraine
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Scott R Johnstone
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA 22908, USA.
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TT, UK.
| | - Annette Graham
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Sebastian Greenhough
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Patricia E M Martin
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
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18
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Tarzemany R, Jiang G, Jiang JX, Larjava H, Häkkinen L. Connexin 43 Hemichannels Regulate the Expression of Wound Healing-Associated Genes in Human Gingival Fibroblasts. Sci Rep 2017; 7:14157. [PMID: 29074845 PMCID: PMC5658368 DOI: 10.1038/s41598-017-12672-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/18/2017] [Indexed: 02/01/2023] Open
Abstract
Connexin 43 (Cx43) is the most ubiquitous connexin in various cells, and presents as hemichannels (HCs) and gap junctions (GJs) on the cell membrane. We have recently shown that Cx43 abundance was strongly reduced in fibroblasts of human gingival wounds, and blocking Cx43 function in cultured human gingival fibroblasts (GFBLs) strongly regulated the expression of wound healing-related genes. However, it is not known whether these responses involved Cx43 HCs or GJs. Here we show that Cx43 assembled into distinct GJ and HC plaques in GFBLs both in vivo and in vitro. Specific blockage of Cx43 HC function by TAT-Gap19, a Cx43 mimetic peptide, significantly upregulated the expression of several MMPs, TGF-β signaling molecules, Tenascin-C, and VEGF-A, while pro-fibrotic molecules, including several extracellular matrix proteins and myofibroblast and cell contractility-related molecules, were significantly downregulated. These changes were linked with TAT-Gap19-induced suppression of ATP signaling and activation of the ERK1/2 signaling pathway. Collectively, our data suggest that reduced Cx43 HC function could promote fast and scarless gingival wound healing. Thus, selective suppression of Cx43 HCs may provide a novel target to modulate wound healing.
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Affiliation(s)
- Rana Tarzemany
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Guoqiao Jiang
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Jean X Jiang
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas, 78229-3900, USA
| | - Hannu Larjava
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Lari Häkkinen
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.
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19
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Elbadawy HM, Mirabelli P, Xeroudaki M, Parekh M, Bertolin M, Breda C, Cagini C, Ponzin D, Lagali N, Ferrari S. Effect of connexin 43 inhibition by the mimetic peptide Gap27 on corneal wound healing, inflammation and neovascularization. Br J Pharmacol 2016; 173:2880-93. [PMID: 27472295 PMCID: PMC5055138 DOI: 10.1111/bph.13568] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 06/30/2016] [Accepted: 07/16/2016] [Indexed: 12/13/2022] Open
Abstract
Background and Purpose The connexin 43 (Cx43) mimetic peptide Gap27 was designed to transiently block the function of this gap junction. This study was undertaken to investigate the effect of Gap27 on corneal healing, inflammation and neovascularization. Experimental Approach The effect of Gap27 on wound healing, inflammation and vascularization was assessed in primary human corneal epithelial cells (HCEC) in vitro and whole human corneas ex vivo, and in an in vivo rat wound healing model. Key Results Gap27 enhanced the wound closure of HCEC in vitro and accelerated wound closure and stratification of epithelium in human corneas ex vivo, but did not suppress the corneal release of inflammatory mediators IL‐6 or TNF‐α in vivo. In human corneas ex vivo, F4/80 positive macrophages were observed around the wound site. In vivo, topical Gap27 treatment enhanced the speed and density of early granulocyte infiltration into rat corneas. After 7 days, the expressions of TNF‐α and TGFβ1 were elevated and correlated with inflammatory cell accumulation in the tissue. Additionally, Gap27 did not suppress VEGF release in organotypic culture, nor did it suppress early or late VEGFA expression or neovascularization in vivo. Conclusions and Implications Gap27 can be effective in promoting the healing of superficial epithelial wounds, but in deep stromal wounds it has the potential to promote inflammatory cell migration and accumulation in the tissue and does not suppress the subsequent neovascularization response. These results support the proposal that Gap27 acts as a healing agent in the transient, early stages of corneal epithelial wounding.
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Affiliation(s)
- Hossein Mostafa Elbadawy
- Department of Pharmacology and Toxicology, College of Pharmacy, Taibah University, AlMadinah AlMunawwarah, Saudi Arabia. .,International Center for Ocular Physiopathology, The Veneto Eye Bank Foundation, Venice, Italy.
| | - Pierfrancesco Mirabelli
- Department of Ophthalmology, Institute for Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, Linkoping, Sweden
| | - Maria Xeroudaki
- Department of Ophthalmology, Institute for Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, Linkoping, Sweden
| | - Mohit Parekh
- International Center for Ocular Physiopathology, The Veneto Eye Bank Foundation, Venice, Italy
| | - Marina Bertolin
- International Center for Ocular Physiopathology, The Veneto Eye Bank Foundation, Venice, Italy
| | - Claudia Breda
- International Center for Ocular Physiopathology, The Veneto Eye Bank Foundation, Venice, Italy
| | - Carlo Cagini
- Department of Ophthalmology, Perugia General Hospital, University of Perugia, Perugia, Italy
| | - Diego Ponzin
- International Center for Ocular Physiopathology, The Veneto Eye Bank Foundation, Venice, Italy
| | - Neil Lagali
- Department of Ophthalmology, Institute for Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, Linkoping, Sweden
| | - Stefano Ferrari
- International Center for Ocular Physiopathology, The Veneto Eye Bank Foundation, Venice, Italy
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20
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Xu J, Shao M, Pan H, Wang H, Cheng L, Yang H, Hu T. Novel role of zonula occludens-1: A tight junction protein closely associated with the odontoblast differentiation of human dental pulp cells. Cell Biol Int 2016; 40:787-95. [PMID: 27109589 DOI: 10.1002/cbin.10617] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/21/2016] [Indexed: 02/05/2023]
Abstract
Zonula occludens-1 (ZO-1), a tight junction protein, contributes to the maintenance of the polarity of odontoblasts and junctional complex formation in odontoblast layer during tooth development. However, expression and possible role of ZO-1 in human dental pulp cells (hDPCs) during repair process remains unknown. Here, we investigated the expression of ZO-1 in hDPCs and the relationship with odontoblast differentiation. We found the processes of two adjacent cells were fused and formed junction-like structure using scanning electron microscopy. Fluorescence immunoassay and Western blot confirmed ZO-1 expression in hDPCs. Especially, ZO-1 was high expressed at the cell-cell junction sites. More interestingly, ZO-1 accumulated at the leading edge of lamellipodia in migrating cells when a scratch assay was performed. Furthermore, ZO-1 gradual increased during odontoblast differentiation and ZO-1 silencing greatly inhibited the differentiation. ZO-1 binds directly to actin filaments and RhoA/ROCK signaling mainly regulates cell cytoskeleton, thus RhoA/ROCK might play a role in regulating ZO-1. Lysophosphatidic acid (LPA) and Y-27632 were used to activate and inhibit RhoA/ROCK signaling, respectively, with or without mineralizing medium. In normal cultured hDPCs, RhoA activation increased ZO-1 expression and especially in intercellular contacts, whereas ROCK inhibition attenuated the effects induced by LPA. However, expression of ZO-1 was upregulated by Y-27632 but not significantly affected by LPA after odontoblast differentiation. Hence, ZO-1 highly expresses in cell-cell junctions and is related to odontoblast differentiation, which may contribute to dental pulp repair or even the formation of an odontoblast layer. RhoA/ROCK signaling is involved in the regulation of ZO-1.
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Affiliation(s)
- Jue Xu
- State Key Laboratory of Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Meiying Shao
- State Key Laboratory of Oral Diseases, College of Life Sciences, Sichuan University, Chengdu, China
| | - Hongying Pan
- State Key Laboratory of Oral Diseases, Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Huning Wang
- State Key Laboratory of Oral Diseases, Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Li Cheng
- State Key Laboratory of Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Hui Yang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Tao Hu
- State Key Laboratory of Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,State Key Laboratory of Oral Diseases, Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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21
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Connexin43 plays diverse roles in co-ordinating cell migration and wound closure events. Biochem Soc Trans 2016; 43:482-8. [PMID: 26009195 DOI: 10.1042/bst20150034] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Chronic wounds are not only debilitating to patients, but also impose a huge financial burden on healthcare providers, as current treatments are not particularly effective. Wound healing is a highly co-ordinated process involving a vast array of signalling molecules and different cell types, therefore a substantial amount of research has been carried out in the quest to develop new therapies. The gap junction (GJ) protein connexin43 (Cx43) is one of the many molecules whose expression has been found to be up-regulated in chronic wounds and as a result targeting it may have therapeutic potential. Two different approaches have been adopted to investigate this: knockdown of Cx43 using antisense oligonucleotides and connexin mimetic peptides (CMPs) which inhibit the function of Cx43 without affecting gene expression. These peptides are targeted to the C-terminal domain or the extracellular loops of Cx43 and thus are likely to function by different means. However, both block channel function and have been shown to enhance cell migration rates. In recent years, non-channel functions have emerged for Cx43, many of which are linked to cytoskeletal dynamics and the extracellular matrix (ECM), showing that Cx43 plays diverse roles in co-ordinating wound closure events. It is clear that both CMPs and antisense oligonucleotides hold therapeutic potential, however maintaining Cx43 expression may be beneficial to the cell by preserving other non-channel functions of Cx43. Recent data in the field will be discussed in this article.
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Manipulating Cx43 expression triggers gene reprogramming events in dermal fibroblasts from oculodentodigital dysplasia patients. Biochem J 2015; 472:55-69. [PMID: 26349540 DOI: 10.1042/bj20150652] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/08/2015] [Indexed: 02/06/2023]
Abstract
Oculodentodigital dysplasia (ODDD) is primarily an autosomal dominant disorder linked to over 70 GJA1 gene [connexin43 (Cx43)] mutations. For nearly a decade, our laboratory has been investigating the relationship between Cx43 and ODDD by expressing disease-linked mutants in reference cells, tissue-relevant cell lines, 3D organ cultures and by using genetically modified mouse models of human disease. Although salient features of Cx43 mutants have been revealed, these models do not necessarily reflect the complexity of the human context. To further overcome these limitations, we have acquired dermal fibroblasts from two ODDD-affected individuals harbouring D3N and V216L mutations in Cx43, along with familial controls. Using these ODDD patient dermal fibroblasts, which naturally produce less GJA1 gene product, along with RNAi and RNA activation (RNAa) approaches, we show that manipulating Cx43 expression triggers cellular gene reprogramming. Quantitative RT-PCR, Western blot and immunofluorescent analysis of ODDD patient fibroblasts show unusually high levels of extracellular matrix (ECM)-interacting proteins, including integrin α5β1, matrix metalloproteinases as well as secreted ECM proteins collagen-I and laminin. Cx43 knockdown in familial control cells produces similar effects on ECM expression, whereas Cx43 transcriptional up-regulation using RNAa decreases production of collagen-I. Interestingly, the enhanced levels of ECM-associated proteins in ODDD V216L fibroblasts is not only a consequence of increased ECM gene expression, but also due to an apparent deficit in collagen-I secretion which may further contribute to impaired collagen gel contraction in ODDD fibroblasts. These findings further illuminate the altered function of Cx43 in ODDD-affected individuals and highlight the impact of manipulating Cx43 expression in human cells.
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Faniku C, Wright CS, Martin PE. Connexins and pannexins in the integumentary system: the skin and appendages. Cell Mol Life Sci 2015; 72:2937-47. [PMID: 26091749 PMCID: PMC11113313 DOI: 10.1007/s00018-015-1969-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
Abstract
The integumentary system comprises the skin and its appendages, which includes hair, nails, feathers, sebaceous and eccrine glands. In this review, we focus on the expression profile of connexins and pannexins throughout the integumentary system in mammals, birds and fish. We provide a picture of the complexity of the connexin/pannexin network illustrating functional importance of these proteins in maintaining the integrity of the epidermal barrier. The differential regulation and expression of connexins and pannexins during skin renewal, together with a number of epidermal, hair and nail abnormalities associated with mutations in connexins, emphasize that the correct balance of connexin and pannexin expression is critical for maintenance of the skin and its appendages with both channel and non-channel functions playing profound roles. Changes in connexin expression during both hair and feather regeneration provide suggestions of specialized communication compartments. Finally, we discuss the potential use of zebrafish as a model for connexin skin biology, where evidence mounts that differential connexin expression is involved in skin patterning and pigmentation.
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Affiliation(s)
- Chrysovalantou Faniku
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow, G4 0BA UK
| | - Catherine S. Wright
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow, G4 0BA UK
| | - Patricia E. Martin
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow, G4 0BA UK
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24
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Cogliati B, Vinken M, Silva TC, Araújo CMM, Aloia TPA, Chaible LM, Mori CMC, Dagli MLZ. Connexin 43 deficiency accelerates skin wound healing and extracellular matrix remodeling in mice. J Dermatol Sci 2015; 79:50-56. [PMID: 25900674 DOI: 10.1016/j.jdermsci.2015.03.019] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/28/2015] [Accepted: 03/30/2015] [Indexed: 01/21/2023]
Abstract
BACKGROUND Cellular channels composed of connexin 43 are known to act as key players in the life cycle of the skin and consequently to underlie skin repair. OBJECTIVE This study was specifically set up to investigate the suite of molecular mechanisms driven by connexin 43-based channels on wound healing. METHODS To this end, a battery of parameters, including re-epithelialization, neovascularization, collagen deposition and extracellular matrix remodeling, was monitored over time during experimentally induced skin repair in heterozygous connexin 43 knockout mice. RESULTS It was found that connexin 43 deficiency accelerates re-epithelialization and wound closure, increases proliferation and activation of dermal fibroblasts, and enhances the expression of extracellular matrix remodeling mediators. CONCLUSION These data substantiate the notion that connexin 43 may represent an interesting therapeutic target in dermal wound healing.
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Affiliation(s)
- Bruno Cogliati
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo (USP), Brazil
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Tereza C Silva
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo (USP), Brazil
| | - Cintia M M Araújo
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo (USP), Brazil
| | - Thiago P A Aloia
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo (USP), Brazil
| | - Lucas M Chaible
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo (USP), Brazil
| | - Cláudia M C Mori
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo (USP), Brazil
| | - Maria L Z Dagli
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo (USP), Brazil
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25
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Hills CE, Price GW, Squires PE. Mind the gap: connexins and cell-cell communication in the diabetic kidney. Diabetologia 2015; 58:233-41. [PMID: 25358446 DOI: 10.1007/s00125-014-3427-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 09/25/2014] [Indexed: 10/24/2022]
Abstract
Connexins, assembled as a hexameric connexon, form a transmembrane hemichannel that provides a conduit for paracrine signalling of small molecules and ions to regulate the activity and function of adjacent cells. When hemichannels align and associate with similar channels on opposing cells, they form a continuous aqueous pore or gap junction, allowing the direct transmission of metabolic and electrical signals between coupled cells. Regulation of gap junction synthesis and channel activity is critical for cell function, and a number of diseases can be attributed to changes in the expression/function of these important proteins. Diabetic nephropathy is associated with several complex metabolic and inflammatory responses characterised by defects at the molecular, cellular and tissue level. In both type 1 and type 2 diabetes, glycaemic injury of the kidney is the leading cause of end-stage renal failure, a consequence of multiple aetiologies, including increased deposition of extracellular matrix, glomerular hyperfiltration, albuminuria and tubulointerstitial fibrosis. In diabetic nephropathy, loss of connexin mediated cell-cell communication within the nephron may represent an early sign of disease; however, our current knowledge of the role of connexins in the diabetic kidney is sparse. This review highlights recent evidence demonstrating that maintenance of connexin-mediated cell-cell communication could benefit region-specific renal function in diabetic nephropathy and suggests that these proteins should be viewed as a tantalising novel target for therapeutic intervention.
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Affiliation(s)
- Claire E Hills
- School of Life Sciences, University of Lincoln, Brayford Pool, Lincoln, LN6 7TS, UK,
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26
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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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27
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Tarzemany R, Jiang G, Larjava H, Häkkinen L. Expression and function of connexin 43 in human gingival wound healing and fibroblasts. PLoS One 2015; 10:e0115524. [PMID: 25584940 PMCID: PMC4293150 DOI: 10.1371/journal.pone.0115524] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 11/25/2014] [Indexed: 11/18/2022] Open
Abstract
Connexins (C×s) are a family of transmembrane proteins that form hemichannels and gap junctions (GJs) on the cell membranes, and transfer small signaling molecules between the cytoplasm and extracellular space and between connecting cells, respectively. Among C×s, suppressing C×43 expression or function promotes skin wound closure and granulation tissue formation, and may alleviate scarring, but the mechanisms are not well understood. Oral mucosal gingiva is characterized by faster wound closure and scarless wound healing outcome as compared to skin wounds. Therefore, we hypothesized that C×43 function is down regulated during human gingival wound healing, which in fibroblasts promotes expression of genes conducive for fast and scarless wound healing. Cultured gingival fibroblasts expressed C×43 as their major connexin. Immunostaining of unwounded human gingiva showed that C×43 was abundantly present in the epithelium, and in connective tissue formed large C×43 plaques in fibroblasts. At the early stages of wound healing, C×43 was strongly down regulated in wound epithelial cells and fibroblasts, returning to the level of normal tissue by day 60 post-wounding. Blocking of C×43 function by C×43 mimetic peptide Gap27 suppressed GJ-mediated dye transfer, promoted migration, and caused significant changes in the expression of wound healing-associated genes in gingival fibroblasts. In particular, out of 54 genes analyzed, several MMPs and TGF-β1, involved in regulation of inflammation and extracellular matrix (ECM) turnover, and VEGF-A, involved in angiogenesis, were significantly upregulated while pro-fibrotic ECM molecules, including Collagen type I, and cell contractility-related molecules were significantly down regulated. These responses involved MAPK, GSK3α/β and TGF-β signaling pathways, and AP1 and SP1 transcription factors. Thus, suppressed function of C×43 in fibroblasts promotes their migration, and regulates expression of wound healing-associated genes via AP1, SP1, MAPK, GSK3α/β and TGF-β signaling pathways, and may promote fast and scarless wound healing in human gingiva.
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Affiliation(s)
- Rana Tarzemany
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada
| | - Guoqiao Jiang
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada
| | - Hannu Larjava
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada
| | - Lari Häkkinen
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada
- * E-mail:
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28
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O'Carroll SJ, Becker DL, Davidson JO, Gunn AJ, Nicholson LFB, Green CR. The use of connexin-based therapeutic approaches to target inflammatory diseases. Methods Mol Biol 2014; 1037:519-46. [PMID: 24029957 DOI: 10.1007/978-1-62703-505-7_31] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Alterations in Connexin43 (Cx43) expression levels have been shown to play a role in inflammatory processes including skin wounding and neuroinflammation. Cx43 protein levels increase following a skin wound and can inhibit wound healing. Increased Cx43 has been observed following stroke, epilepsy, ischemia, optic nerve damage, and spinal cord injury with gap junctional communication and hemichannel opening leading to increased secondary damage via the inflammatory response. Connexin43 modulation has been identified as a potential target for protection and repair in neuroinflammation and skin wound repair. This review describes the use of a Cx43 specific antisense oligonucleotide (Cx43 AsODN) and peptide mimetics of the connexin extracellular loop domain to modulate Cx43 expression and/or function in inflammatory disorders of the skin and central nervous system. An overview of the role of connexin43 in inflammatory conditions, how antisense and peptide have allowed us to elucidate the role of Cx43 in these diseases, create models of diseases to test interventions and their potential for use clinically or in current clinical trials is presented. Antisense oligonucleotides are applied topically and have been used to improve wound healing following skin injury. They have also been used to develop ex vivo models of neuroinflammatory diseases that will allow testing of intervention strategies. The connexin mimetic peptides have shown potential in a number of neuroinflammatory disorders in ex vivo models as well as in vivo when delivered directly to the injury site or when delivered systemically.
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Affiliation(s)
- Simon J O'Carroll
- Department of Anatomy with Radiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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29
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Suzuki K, Tanaka S, Yanagi K, Iijima T, Niitani M, Coletta C, Szabo C, Aso Y. Epalrestat induces cell proliferation and migration in endothelial cells via mTOR activation through PI3/Akt signaling. Diabetol Int 2014. [DOI: 10.1007/s13340-013-0138-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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30
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Martin PE, Easton JA, Hodgins MB, Wright CS. Connexins: sensors of epidermal integrity that are therapeutic targets. FEBS Lett 2014; 588:1304-14. [PMID: 24607543 DOI: 10.1016/j.febslet.2014.02.048] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 02/25/2014] [Accepted: 02/25/2014] [Indexed: 12/25/2022]
Abstract
Gap junction proteins (connexins) are differentially expressed throughout the multiple layers of the epidermis. A variety of skin conditions arise with aberrant connexin expression or function and suggest that maintaining the epidermal gap junction network has many important roles in preserving epidermal integrity and homeostasis. Mutations in a number of connexins lead to epidermal dysplasias giving rise to a range of dermatological disorders of differing severity. 'Gain of function' mutations reveal connexin-mediated roles in calcium signalling within the epidermis. Connexins are involved in epidermal innate immunity, inflammation control and in wound repair. The therapeutic potential of targeting connexins to improve wound healing responses is now clear. This review discusses the role of connexins in epidermal integrity, and examines the emerging evidence that connexins act as epidermal sensors to a variety of mechanical, temperature, pathogen-induced and chemical stimuli. Connexins thus act as an integral component of the skin's protective barrier.
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Affiliation(s)
- Patricia E Martin
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Jennifer A Easton
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow G4 0BA, UK; Department of Dermatology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Malcolm B Hodgins
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow G4 0BA, UK
| | - Catherine S Wright
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow G4 0BA, UK
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31
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Degen KE, Gourdie RG. Embryonic wound healing: a primer for engineering novel therapies for tissue repair. ACTA ACUST UNITED AC 2013; 96:258-70. [PMID: 23109321 DOI: 10.1002/bdrc.21019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Scar is the default tissue repair used by the body in response to most injuries-a response that occurs in wounds ranging in seriousness from minor skin cuts to complete severance of the spinal cord. By contrast, before the third trimester of pregnancy embryonic mammals tend to heal without scarring due to a variety of mechanisms and factors that are uniquely in operation during development in utero. The goal of tissue engineering is to develop safe and clinically effective biological substitutes that restore, maintain, or improve tissue function in patients. This review provides a comparative overview of wound healing during development and maturation and seeks to provide a perspective on just how much the embryo may be able teach us in the engineering of new therapies for tissue repair.
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Affiliation(s)
- Katherine E Degen
- School of Biomedical Engineering Science, Virginia Tech, Blacksburg, USA
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32
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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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33
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Evans WH, Bultynck G, Leybaert L. Manipulating connexin communication channels: use of peptidomimetics and the translational outputs. J Membr Biol 2012; 245:437-49. [PMID: 22886208 PMCID: PMC3456916 DOI: 10.1007/s00232-012-9488-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 07/07/2012] [Indexed: 12/22/2022]
Abstract
Gap junctions are key components underpinning multicellularity. They provide cell to cell channel pathways that enable direct intercellular communication and cellular coordination in tissues and organs. The channels are constructed of a family of connexin (Cx) membrane proteins. They oligomerize inside the cell, generating hemichannels (connexons) composed of six subunits arranged around a central channel. After transfer to the plasma membrane, arrays of Cx hemichannels (CxHcs) interact and couple with partners in neighboring attached cells to generate gap junctions. Cx channels have been studied using a range of technical approaches. Short peptides corresponding to sequences in the extra- and intracellular regions of Cxs were used first to generate epitope-specific antibodies that helped studies on the organization and functions of gap junctions. Subsequently, the peptides themselves, especially Gap26 and -27, mimetic peptides derived from each of the two extracellular loops of connexin43 (Cx43), a widely distributed Cx, have been extensively applied to block Cx channels and probe the biology of cell communication. The development of a further series of short peptides mimicking sequences in the intracellular loop, especially the extremity of the intracellular carboxyl tail of Cx43, followed. The primary inhibitory action of the peptidomimetics occurs at CxHcs located at unapposed regions of the cell's plasma membrane, followed by inhibition of cell coupling occurring across gap junctions. CxHcs respond to a range of environmental conditions by increasing their open probability. Peptidomimetics provide a way to block the actions of CxHcs with some selectivity. Furthermore, they are increasingly applied to address the pathological consequences of a range of environmental stresses that are thought to influence Cx channel operation. Cx peptidomimetics show promise as candidates in developing new therapeutic approaches for containing and reversing damage inflicted on CxHcs, especially in hypoxia and ischemia in the heart and in brain functions.
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Affiliation(s)
- W Howard Evans
- Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff, Wales CF14 4XN, UK.
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34
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Overexpression of the gap junction protein Cx43 as found in diabetic foot ulcers can retard fibroblast migration. Cell Biol Int 2012; 36:661-7. [DOI: 10.1042/cbi20110628] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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35
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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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36
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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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37
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Becker DL, Thrasivoulou C, Phillips ARJ. Connexins in wound healing; perspectives in diabetic patients. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:2068-75. [PMID: 22155211 DOI: 10.1016/j.bbamem.2011.11.017] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 11/07/2011] [Accepted: 11/18/2011] [Indexed: 11/19/2022]
Abstract
Skin lesions are common events and we have evolved to rapidly heal them in order to maintain homeostasis and prevent infection and sepsis. Most acute wounds heal without issue, but as we get older our bodies become compromised by poor blood circulation and conditions such as diabetes, leading to slower healing. This can result in stalled or hard-to-heal chronic wounds. Currently about 2% of the Western population develop a chronic wound and this figure will rise as the population ages and diabetes becomes more prevalent [1]. Patient morbidity and quality of life are profoundly altered by chronic wounds [2]. Unfortunately a significant proportion of these chronic wounds fail to respond to conventional treatment and can result in amputation of the lower limb. Life quality and expectancy following amputation is severely reduced. These hard to heal wounds also represent a growing economic burden on Western society with published estimates of costs to healthcare services in the region of $25B annually [3]. There exists a growing need for specific and effective therapeutic agents to improve healing in these wounds. In recent years the gap junction protein Cx43 has been shown to play a pivotal role early on in the acute wound healing process at a number of different levels [4-7]. Conversely, abnormal expression of Cx43 in wound edge keratinocytes was shown to underlie the poor rate of healing in diabetic rats, and targeting its expression with an antisense gel restored normal healing rates [8]. The presence of Cx43 in the wound edge keratinocytes of human chronic wounds has also been reported [9]. Abnormal Cx43 biology may underlie the poor healing of human chronic wounds and be amenable therapeutic intervention [7]. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Affiliation(s)
- David L Becker
- Department of Cell and Developmental Biology, University College, London, WC1E 6BT, UK.
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