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Domingues N, Catarino S, Cristóvão B, Rodrigues L, Carvalho FA, Sarmento MJ, Zuzarte M, Almeida J, Ribeiro-Rodrigues T, Correia-Rodrigues Â, Fernandes F, Rodrigues-Santos P, Aasen T, Santos NC, Korolchuk VI, Gonçalves T, Milosevic I, Raimundo N, Girão H. Connexin43 promotes exocytosis of damaged lysosomes through actin remodelling. EMBO J 2024:10.1038/s44318-024-00177-3. [PMID: 39044100 DOI: 10.1038/s44318-024-00177-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 07/04/2024] [Accepted: 07/09/2024] [Indexed: 07/25/2024] Open
Abstract
A robust and efficient cellular response to lysosomal membrane damage prevents leakage from the lysosome lumen into the cytoplasm. This response is understood to happen through either lysosomal membrane repair or lysophagy. Here we report exocytosis as a third response mechanism to lysosomal damage, which is further potentiated when membrane repair or lysosomal degradation mechanisms are impaired. We show that Connexin43 (Cx43), a protein canonically associated with gap junctions, is recruited from the plasma membrane to damaged lysosomes, promoting their secretion and accelerating cell recovery. The effects of Cx43 on lysosome exocytosis are mediated by a reorganization of the actin cytoskeleton that increases plasma membrane fluidity and decreases cell stiffness. Furthermore, we demonstrate that Cx43 interacts with the actin nucleator Arp2, the activity of which was shown to be necessary for Cx43-mediated actin rearrangement and lysosomal exocytosis following damage. These results define a novel mechanism of lysosomal quality control whereby Cx43-mediated actin remodelling potentiates the secretion of damaged lysosomes.
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Affiliation(s)
- Neuza Domingues
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
| | - Steve Catarino
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Beatriz Cristóvão
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Lisa Rodrigues
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Filomena A Carvalho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Maria João Sarmento
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Mónica Zuzarte
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Jani Almeida
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Teresa Ribeiro-Rodrigues
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Ânia Correia-Rodrigues
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Fábio Fernandes
- Institute for Bioengineering and Biosciences (IBB) and Associate Laboratory i4HB-Institute for Health and Bioeconomy, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Paulo Rodrigues-Santos
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Trond Aasen
- Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Viktor I Korolchuk
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Teresa Gonçalves
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Ira Milosevic
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
- University of Oxford, Centre for Human Genetics, Nuffield Department of Medicine, Oxford, UK
| | - Nuno Raimundo
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - Henrique Girão
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal.
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal.
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal.
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal.
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Jara O, Maripillán J, Momboisse F, Cárdenas AM, García IE, Martínez AD. Differential Regulation of Hemichannels and Gap Junction Channels by RhoA GTPase and Actin Cytoskeleton: A Comparative Analysis of Cx43 and Cx26. Int J Mol Sci 2024; 25:7246. [PMID: 39000353 PMCID: PMC11242593 DOI: 10.3390/ijms25137246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/21/2024] [Accepted: 06/25/2024] [Indexed: 07/16/2024] Open
Abstract
Connexins (Cxs) are transmembrane proteins that assemble into gap junction channels (GJCs) and hemichannels (HCs). Previous researches support the involvement of Rho GTPases and actin microfilaments in the trafficking of Cxs, formation of GJCs plaques, and regulation of channel activity. Nonetheless, it remains uncertain whether distinct types of Cxs HCs and GJCs respond differently to Rho GTPases or changes in actin polymerization/depolymerization dynamics. Our investigation revealed that inhibiting RhoA, a small GTPase that controls actin polymerization, or disrupting actin microfilaments with cytochalasin B (Cyto-B), resulted in reduced GJCs plaque size at appositional membranes and increased transport of HCs to non-appositional plasma membrane regions. Notably, these effects were consistent across different Cx types, since Cx26 and Cx43 exhibited similar responses, despite having distinct trafficking routes to the plasma membrane. Functional assessments showed that RhoA inhibition and actin depolymerization decreased the activity of Cx43 GJCs while significantly increasing HC activity. However, the functional status of GJCs and HCs composed of Cx26 remained unaffected. These results support the hypothesis that RhoA, through its control of the actin cytoskeleton, facilitates the transport of HCs to appositional cell membranes for GJCs formation while simultaneously limiting the positioning of free HCs at non-appositional cell membranes, independently of Cx type. This dynamic regulation promotes intercellular communications and reduces non-selective plasma membrane permeability through a Cx-type dependent mechanism, whereby the activity of Cx43 HCs and GJCs are differentially affected but Cx26 channels remain unchanged.
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Affiliation(s)
- Oscar Jara
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencia, Universidad de Valparaíso, Valparaíso 2362807, Chile
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA
| | - Jaime Maripillán
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencia, Universidad de Valparaíso, Valparaíso 2362807, Chile
| | - Fanny Momboisse
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencia, Universidad de Valparaíso, Valparaíso 2362807, Chile
- Virus and Immunity Unit, Institut Pasteur, Université Paris Cité, CNRS UMR3569, 75013 Paris, France
| | - Ana María Cárdenas
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencia, Universidad de Valparaíso, Valparaíso 2362807, Chile
| | - Isaac E García
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencia, Universidad de Valparaíso, Valparaíso 2362807, Chile
- Laboratorio de Fisiología Molecular y Biofísica, Facultad de Odontología, Universidad de Valparaíso, Valparaíso 2360004, Chile
- Centro de Investigación en Ciencias Odontológicas y Médicas, CICOM, Universidad de Valparaíso, Valparaíso 2360004, Chile
| | - Agustín D Martínez
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencia, Universidad de Valparaíso, Valparaíso 2362807, Chile
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Higdon AL, Won NH, Brar GA. Truncated protein isoforms generate diversity of protein localization and function in yeast. Cell Syst 2024; 15:388-408.e4. [PMID: 38636458 PMCID: PMC11075746 DOI: 10.1016/j.cels.2024.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 01/21/2024] [Accepted: 03/20/2024] [Indexed: 04/20/2024]
Abstract
Genome-wide measurement of ribosome occupancy on mRNAs has enabled empirical identification of translated regions, but high-confidence detection of coding regions that overlap annotated coding regions has remained challenging. Here, we report a sensitive and robust algorithm that revealed the translation of 388 N-terminally truncated proteins in budding yeast-more than 30-fold more than previously known. We extensively experimentally validated them and defined two classes. The first class lacks large portions of the annotated protein and tends to be produced from a truncated transcript. We show that two such cases, Yap5truncation and Pus1truncation, have condition-specific regulation and distinct functions from their respective annotated isoforms. The second class of truncated protein isoforms lacks only a small region of the annotated protein and is less likely to be produced from an alternative transcript isoform. Many display different subcellular localizations than their annotated counterpart, representing a common strategy for dual localization of otherwise functionally identical proteins. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- Andrea L Higdon
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Nathan H Won
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Gloria A Brar
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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Padget RL, Zeitz MJ, Blair GA, Wu X, North MD, Tanenbaum MT, Stanley KE, Phillips CM, King DR, Lamouille S, Gourdie RG, Hoeker GS, Swanger SA, Poelzing S, Smyth JW. Acute Adenoviral Infection Elicits an Arrhythmogenic Substrate Prior to Myocarditis. Circ Res 2024; 134:892-912. [PMID: 38415360 PMCID: PMC11003857 DOI: 10.1161/circresaha.122.322437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/12/2024] [Indexed: 02/29/2024]
Abstract
BACKGROUND Viral cardiac infection represents a significant clinical challenge encompassing several etiological agents, disease stages, complex presentation, and a resulting lack of mechanistic understanding. Myocarditis is a major cause of sudden cardiac death in young adults, where current knowledge in the field is dominated by later disease phases and pathological immune responses. However, little is known regarding how infection can acutely induce an arrhythmogenic substrate before significant immune responses. Adenovirus is a leading cause of myocarditis, but due to species specificity, models of infection are lacking, and it is not understood how adenoviral infection may underlie sudden cardiac arrest. Mouse adenovirus type-3 was previously reported as cardiotropic, yet it has not been utilized to understand the mechanisms of cardiac infection and pathology. METHODS We have developed mouse adenovirus type-3 infection as a model to investigate acute cardiac infection and molecular alterations to the infected heart before an appreciable immune response or gross cardiomyopathy. RESULTS Optical mapping of infected hearts exposes decreases in conduction velocity concomitant with increased Cx43Ser368 phosphorylation, a residue known to regulate gap junction function. Hearts from animals harboring a phospho-null mutation at Cx43Ser368 are protected against mouse adenovirus type-3-induced conduction velocity slowing. Additional to gap junction alterations, patch clamping of mouse adenovirus type-3-infected adult mouse ventricular cardiomyocytes reveals prolonged action potential duration as a result of decreased IK1 and IKs current density. Turning to human systems, we find human adenovirus type-5 increases phosphorylation of Cx43Ser368 and disrupts synchrony in human induced pluripotent stem cell-derived cardiomyocytes, indicating common mechanisms with our mouse whole heart and adult cardiomyocyte data. CONCLUSIONS Together, these findings demonstrate that adenoviral infection creates an arrhythmogenic substrate through direct targeting of gap junction and ion channel function in the heart. Such alterations are known to precipitate arrhythmias and likely contribute to sudden cardiac death in acutely infected patients.
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Affiliation(s)
- Rachel L. Padget
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Michael J. Zeitz
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Grace A. Blair
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Xiaobo Wu
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Michael D. North
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
| | | | - Kari E. Stanley
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Chelsea M. Phillips
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - D. Ryan King
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Samy Lamouille
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Robert G. Gourdie
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - Gregory S. Hoeker
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
| | - Sharon A. Swanger
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA
| | - Steven Poelzing
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - James W. Smyth
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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Irwin RM, Thomas MA, Fahey MJ, Mayán MD, Smyth JW, Delco ML. Connexin 43 Regulates Intercellular Mitochondrial Transfer from Human Mesenchymal Stromal Cells to Chondrocytes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585552. [PMID: 38562828 PMCID: PMC10983985 DOI: 10.1101/2024.03.18.585552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Background The phenomenon of intercellular mitochondrial transfer from mesenchymal stromal cells (MSCs) has shown promise for improving tissue healing after injury and has potential for treating degenerative diseases like osteoarthritis (OA). Recently MSC to chondrocyte mitochondrial transfer has been documented, but the mechanism of transfer is unknown. Full-length connexin43 (Cx43, encoded by GJA1 ) and the truncated internally translated isoform GJA1-20k have been implicated in mitochondrial transfer between highly oxidative cells, but have not been explored in orthopaedic tissues. Here, our goal was to investigate the role of Cx43 in MSC to chondrocyte mitochondrial transfer. In this study, we tested the hypotheses that (a) mitochondrial transfer from MSCs to chondrocytes is increased when chondrocytes are under oxidative stress and (b) MSC Cx43 expression mediates mitochondrial transfer to chondrocytes. Methods Oxidative stress was induced in immortalized human chondrocytes using tert-Butyl hydroperoxide (t-BHP) and cells were evaluated for mitochondrial membrane depolarization and reactive oxygen species (ROS) production. Human bone-marrow derived MSCs were transduced for mitochondrial fluorescence using lentiviral vectors. MSC Cx43 expression was knocked down using siRNA or overexpressed (GJA1+ and GJA1-20k+) using lentiviral transduction. Chondrocytes and MSCs were co-cultured for 24 hrs in direct contact or separated using transwells. Mitochondrial transfer was quantified using flow cytometry. Co-cultures were fixed and stained for actin and Cx43 to visualize cell-cell interactions during transfer. Results Mitochondrial transfer was significantly higher in t-BHP-stressed chondrocytes. Contact co-cultures had significantly higher mitochondrial transfer compared to transwell co-cultures. Confocal images showed direct cell contacts between MSCs and chondrocytes where Cx43 staining was enriched at the terminal ends of actin cellular extensions containing mitochondria in MSCs. MSC Cx43 expression was associated with the magnitude of mitochondrial transfer to chondrocytes; knocking down Cx43 significantly decreased transfer while Cx43 overexpression significantly increased transfer. Interestingly, GJA1-20k expression was highly correlated with incidence of mitochondrial transfer from MSCs to chondrocytes. Conclusions Overexpression of GJA1-20k in MSCs increases mitochondrial transfer to chondrocytes, highlighting GJA1-20k as a potential target for promoting mitochondrial transfer from MSCs as a regenerative therapy for cartilage tissue repair in OA.
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Aalders J, Léger L, Van der Meeren L, Sinha S, Skirtach AG, De Backer J, van Hengel J. Three-dimensional co-culturing of stem cell-derived cardiomyocytes and cardiac fibroblasts reveals a role for both cell types in Marfan-related cardiomyopathy. Matrix Biol 2024; 126:14-24. [PMID: 38224822 DOI: 10.1016/j.matbio.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 01/12/2024] [Accepted: 01/12/2024] [Indexed: 01/17/2024]
Abstract
Pathogenic variants in the FBN1 gene, which encodes the extracellular matrix protein fibrillin-1, cause Marfan syndrome (MFS), which affects multiple organ systems, including the cardiovascular system. Myocardial dysfunction has been observed in a subset of patients with MFS and in several MFS mouse models. However, there is limited understanding of the intrinsic consequences of FBN1 variants on cardiomyocytes (CMs). To elucidate the CM-specific contribution in Marfan's cardiomyopathy, cardiosphere cultures of CMs and cardiac fibroblasts (CFs) are used. CMs and CFs were derived by human induced pluripotent stem cell (iPSC) differentiation from MFS iPSCs with a pathogenic variant in FBN1 (c.3725G>A; p.Cys1242Tyr) and the corresponding CRISPR-corrected iPSC line (Cor). Cardiospheres containing MFS CMs show decreased FBN1, COL1A2 and GJA1 expression. MFS CMs cultured in cardiospheres have fewer binucleated CMs in comparison with Cor CMs. 13% of MFS CMs in cardiospheres are binucleated and 15% and 16% in cardiospheres that contain co-cultures with respectively MFS CFs and Cor CFs, compared to Cor CMs, that revealed up to 23% binucleation when co-cultured with CFs. The sarcomere length of CMs, as a marker of development, is significantly increased in MFS CMs interacting with Cor CF or MFS CF, as compared to monocultured MFS CMs. Nuclear blebbing was significantly more frequent in MFS CFs, which correlated with increased stiffness of the nuclear area compared to Cor CFs. Our cardiosphere model for Marfan-related cardiomyopathy identified a contribution of CFs in Marfan-related cardiomyopathy and suggests that abnormal early development of CMs may play a role in the disease mechanism.
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Affiliation(s)
- Jeffrey Aalders
- Medical Cell Biology Research Group, Department of Human Structure and Repair, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Laurens Léger
- Medical Cell Biology Research Group, Department of Human Structure and Repair, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Louis Van der Meeren
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Sanjay Sinha
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Andre G Skirtach
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Julie De Backer
- Centre for Medical Genetics, Ghent University Hospital, Belgium and Department of Biomolecular Medicine, Ghent University, Ghent, Belgium; Department of Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Jolanda van Hengel
- Medical Cell Biology Research Group, Department of Human Structure and Repair, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
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Al-attar R, Jargstorf J, Romagnuolo R, Jouni M, Alibhai FJ, Lampe PD, Solan JL, Laflamme MA. Casein Kinase 1 Phosphomimetic Mutations Negatively Impact Connexin-43 Gap Junctions in Human Pluripotent Stem Cell-Derived Cardiomyocytes. Biomolecules 2024; 14:61. [PMID: 38254663 PMCID: PMC10813327 DOI: 10.3390/biom14010061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/14/2023] [Accepted: 12/25/2023] [Indexed: 01/24/2024] Open
Abstract
The transplantation of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) has shown promise in preclinical models of myocardial infarction, but graft myocardium exhibits incomplete host-graft electromechanical integration and a propensity for pro-arrhythmic behavior. Perhaps contributing to this situation, hPSC-CM grafts show low expression of connexin 43 (Cx43), the major gap junction (GJ) protein, in ventricular myocardia. We hypothesized that Cx43 expression and function could be rescued by engineering Cx43 in hPSC-CMs with a series of phosphatase-resistant mutations at three casein kinase 1 phosphorylation sites (Cx43-S3E) that have been previously reported to stabilize Cx43 GJs and reduce arrhythmias in transgenic mice. However, contrary to our predictions, transgenic Cx43-S3E hPSC-CMs exhibited reduced Cx43 expression relative to wild-type cells, both at baseline and following ischemic challenge. Cx43-S3E hPSC-CMs showed correspondingly slower conduction velocities, increased automaticity, and differential expression of other connexin isoforms and various genes involved in cardiac excitation-contraction coupling. Cx43-S3E hPSC-CMs also had phosphorylation marks associated with Cx43 GJ internalization, a finding that may account for their impaired GJ localization. Taken collectively, our data indicate that the Cx43-S3E mutation behaves differently in hPSC-CMs than in adult mouse ventricular myocytes and that multiple biological factors likely need to be addressed synchronously to ensure proper Cx43 expression, localization, and function.
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Affiliation(s)
- Rasha Al-attar
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Joseph Jargstorf
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Rocco Romagnuolo
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Mariam Jouni
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Faisal J. Alibhai
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Paul D. Lampe
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; (P.D.L.); (J.L.S.)
| | - Joell L. Solan
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; (P.D.L.); (J.L.S.)
| | - Michael A. Laflamme
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON M5G 1L7, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5G 1L7, Canada
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Altas B, Rhee HJ, Ju A, Solís HC, Karaca S, Winchenbach J, Kaplan-Arabaci O, Schwark M, Ambrozkiewicz MC, Lee C, Spieth L, Wieser GL, Chaugule VK, Majoul I, Hassan MA, Goel R, Wojcik SM, Koganezawa N, Hanamura K, Rotin D, Pichler A, Mitkovski M, de Hoz L, Poulopoulos A, Urlaub H, Jahn O, Saher G, Brose N, Rhee J, Kawabe H. Nedd4-2-dependent regulation of astrocytic Kir4.1 and Connexin43 controls neuronal network activity. J Cell Biol 2024; 223:e201902050. [PMID: 38032389 PMCID: PMC10689203 DOI: 10.1083/jcb.201902050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 10/21/2021] [Accepted: 11/02/2023] [Indexed: 12/01/2023] Open
Abstract
Nedd4-2 is an E3 ubiquitin ligase in which missense mutation is related to familial epilepsy, indicating its critical role in regulating neuronal network activity. However, Nedd4-2 substrates involved in neuronal network function have yet to be identified. Using mouse lines lacking Nedd4-1 and Nedd4-2, we identified astrocytic channel proteins inwardly rectifying K+ channel 4.1 (Kir4.1) and Connexin43 as Nedd4-2 substrates. We found that the expression of Kir4.1 and Connexin43 is increased upon conditional deletion of Nedd4-2 in astrocytes, leading to an elevation of astrocytic membrane ion permeability and gap junction activity, with a consequent reduction of γ-oscillatory neuronal network activity. Interestingly, our biochemical data demonstrate that missense mutations found in familial epileptic patients produce gain-of-function of the Nedd4-2 gene product. Our data reveal a process of coordinated astrocytic ion channel proteostasis that controls astrocyte function and astrocyte-dependent neuronal network activity and elucidate a potential mechanism by which aberrant Nedd4-2 function leads to epilepsy.
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Affiliation(s)
- Bekir Altas
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- International Max Planck Research School and the Göttingen Graduate School for Neurosciences, Biophysics and Molecular Biosciences, Göttingen, Germany
- The Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, PhD Program Systems Neuroscience, University of Göttingen, Göttingen, Germany
- Department of Pharmacology and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Hong-Jun Rhee
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Anes Ju
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- The Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, PhD Program Systems Neuroscience, University of Göttingen, Göttingen, Germany
| | - Hugo Cruces Solís
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- International Max Planck Research School and the Göttingen Graduate School for Neurosciences, Biophysics and Molecular Biosciences, Göttingen, Germany
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Samir Karaca
- International Max Planck Research School and the Göttingen Graduate School for Neurosciences, Biophysics and Molecular Biosciences, Göttingen, Germany
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Jan Winchenbach
- The Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, PhD Program Systems Neuroscience, University of Göttingen, Göttingen, Germany
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Oykum Kaplan-Arabaci
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- The Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, PhD Program Molecular Physiology of the Brain, University of Göttingen, Göttingen, Germany
| | - Manuela Schwark
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Mateusz C. Ambrozkiewicz
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- International Max Planck Research School and the Göttingen Graduate School for Neurosciences, Biophysics and Molecular Biosciences, Göttingen, Germany
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - ChungKu Lee
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lena Spieth
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Georg L. Wieser
- City Campus Light Microscopy Facility, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Viduth K. Chaugule
- Department of Epigenetics, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Irina Majoul
- Institute of Biology, Center for Structural and Cell Biology in Medicine, University of Lübeck, Lübeck, Germany
| | - Mohamed A. Hassan
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Protein Research Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Egypt
| | - Rashi Goel
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Sonja M. Wojcik
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Noriko Koganezawa
- Department of Pharmacology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Kenji Hanamura
- Department of Pharmacology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Daniela Rotin
- The Hospital for Sick Children and University of Toronto, Toronto, Canada
| | - Andrea Pichler
- Department of Epigenetics, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Miso Mitkovski
- City Campus Light Microscopy Facility, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Livia de Hoz
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Alexandros Poulopoulos
- Department of Pharmacology and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Bioanalytics, Institute for Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
| | - Olaf Jahn
- Department of Molecular Neurobiology, Neuroproteomics Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Department of Psychiatry and Psychotherapy, Translational Neuroproteomics Group, University Medical Center Göttingen, Göttingen, Germany
| | - Gesine Saher
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - JeongSeop Rhee
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Hiroshi Kawabe
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Department of Pharmacology, Gunma University Graduate School of Medicine, Maebashi, Japan
- Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan
- Department of Gerontology, Laboratory of Molecular Life Science, Institute of Biomedical Research and Innovation, Foundation for Biomedical Research and Innovation at Kobe, Kobe, Japan
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Phillips CM, Johnson AM, Stamatovic SM, Keep RF, Andjelkovic AV. 20 kDa isoform of connexin-43 augments spatial reorganization of the brain endothelial junctional complex and lesion leakage in cerebral cavernous malformation type-3. Neurobiol Dis 2023; 186:106277. [PMID: 37652184 DOI: 10.1016/j.nbd.2023.106277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/14/2023] [Accepted: 08/29/2023] [Indexed: 09/02/2023] Open
Abstract
Cerebral cavernous malformation type-3 (CCM3) is a type of brain vascular malformation caused by mutations in programmed cell death protein-10 (PDCD10). It is characterized by early life occurrence of hemorrhagic stroke and profound blood-brain barrier defects. The pathogenic mechanisms responsible for microvascular hyperpermeability and lesion progression in CCM3 are still largely unknown. The current study examined brain endothelial barrier structural defects formed in the absence of CCM3 in vivo and in vitro that may lead to CCM3 lesion leakage. We found significant upregulation of a 20 kDa isoform of connexin 43 (GJA1-20 k) in brain endothelial cells (BEC) in both non-leaky and leaky lesions, as well as in an in vitro CCM3 knockdown model (CCM3KD-BEC). Morphological, biochemical, FRET, and FRAP analyses of CCM3KD-BEC found GJA1-20 k regulates full-length GJA1 biogenesis, prompting uncontrolled gap junction growth. Furthermore, by binding to a tight junction scaffolding protein, ZO-1, GJA1-20 k interferes with Cx43/ZO-1 interactions and gap junction/tight junction crosstalk, promoting ZO-1 dissociation from tight junction complexes and diminishing claudin-5/ZO-1 interaction. As a consequence, the tight junction complex is destabilized, allowing "replacement" of tight junctions with gap junctions leading to increased brain endothelial barrier permeability. Modifying cellular levels of GJA1-20 k rescued brain endothelial barrier integrity re-establishing the spatial organization of gap and tight junctional complexes. This study highlights generation of potential defects at the CCM3-affected brain endothelial barrier which may underlie prolonged vascular leakiness.
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Affiliation(s)
- Chelsea M Phillips
- Neuroscience Graduate program, University of Michigan, Ann Arbor, MI, USA
| | | | | | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA; Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Anuska V Andjelkovic
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA; Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA.
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Zhang J, Wu X, Liang Y, Kelly G, Burt JM, Zhang L, Wang T. Particulate matter increases connexin 43 expression and exacerbates endothelial barrier disruption. Am J Transl Res 2023; 15:5099-5109. [PMID: 37692924 PMCID: PMC10492082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/29/2023] [Indexed: 09/12/2023]
Abstract
OBJECTIVES Particulate Matter (PM) air pollution is known to exacerbate cardiopulmonary diseases. We previously demonstrated that PM mediates endothelial injury and barrier disruption by modulating the endothelial cytoskeleton and cell-cell junctions, but the effects of PM exposure on cell-cell communication and gap junction activity are still unknown. METHODS This study focused on the characterization of PM-regulated endothelial dysfunction through connexin 43 (Cx43), the most abundant gap junction protein expressed in lung endothelial cells (ECs), using cultured human lung endothelial cells and a well-characterized PM sample. RESULTS PM exposure induced a time-dependent increase of Cx43 in human lung ECs at both the mRNA and protein levels. N-acetylcysteine (NAC), a reactive oxygen species (ROS) scavenger, significantly suppressed PM-induced Cx43 expression. Cx43 proteins on the plasma membrane and ER/Golgi apparatus were elevated in response to a PM challenge. In addition, PM induced gap junction activity, which was indicated by green fluorescence dye transfer between two adjacent ECs. Moreover, GAP27, a selective Cx43 channel inhibitor, attenuated PM-induced human lung EC barrier disruption, which was reflected by rescued trans-endothelial electrical resistance (TER) with an electric cell-substrate impedance sensing system. Moreover, knocking down Cx43 alleviated PM-induced myosin light chain (MLC) phosphorylation. CONCLUSIONS These results strongly suggest that Cx43 plays a key role in PM-mediated endothelial barrier disruption and signal transduction. Cx43 may be a therapeutic target in PM-mediated cardiopulmonary disorders.
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Affiliation(s)
- Jun Zhang
- Department of Medicine, University of ArizonaTuscon, AZ, USA
- Department of Respiratory and Critical Care Medicine, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical UniversityBeijing, China
| | - Xiaomin Wu
- Department of Medicine, University of ArizonaTuscon, AZ, USA
| | - Ying Liang
- Department of Medicine, University of ArizonaTuscon, AZ, USA
| | - Gabriel Kelly
- Department of Medicine, University of ArizonaTuscon, AZ, USA
| | - Janis M Burt
- Department of Physiology, University of ArizonaTuscon, AZ, USA
| | - Liming Zhang
- Department of Respiratory and Critical Care Medicine, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical UniversityBeijing, China
| | - Ting Wang
- Department of Medicine, University of ArizonaTuscon, AZ, USA
- Center of Translational Science, Florida International University11350 SW Village Parkway, Port St. Lucie, FL, USA
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11
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Totland MZ, Omori Y, Sørensen V, Kryeziu K, Aasen T, Brech A, Leithe E. Endocytic trafficking of connexins in cancer pathogenesis. Biochim Biophys Acta Mol Basis Dis 2023:166812. [PMID: 37454772 DOI: 10.1016/j.bbadis.2023.166812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/26/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Gap junctions are specialized regions of the plasma membrane containing clusters of channels that provide for the diffusion of ions and small molecules between adjacent cells. A fundamental role of gap junctions is to coordinate the functions of cells in tissues. Cancer pathogenesis is usually associated with loss of intercellular communication mediated by gap junctions, which may affect tumor growth and the response to radio- and chemotherapy. Gap junction channels consist of integral membrane proteins termed connexins. In addition to their canonical roles in cell-cell communication, connexins modulate a range of signal transduction pathways via interactions with proteins such as β-catenin, c-Src, and PTEN. Consequently, connexins can regulate cellular processes such as cell growth, migration, and differentiation through both channel-dependent and independent mechanisms. Gap junctions are dynamic plasma membrane entities, and by modulating the rate at which connexins undergo endocytosis and sorting to lysosomes for degradation, cells rapidly adjust the level of gap junctions in response to alterations in the intracellular or extracellular milieu. Current experimental evidence indicates that aberrant trafficking of connexins in the endocytic system is intrinsically involved in mediating the loss of gap junctions during carcinogenesis. This review highlights the role played by the endocytic system in controlling connexin degradation, and consequently gap junction levels, and discusses how dysregulation of these processes contributes to the loss of gap junctions during cancer development. We also discuss the therapeutic implications of aberrant endocytic trafficking of connexins in cancer cells.
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Affiliation(s)
| | - Yasufumi Omori
- Department of Molecular and Tumour Pathology, Akita University Graduate School of Medicine, Akita, Japan
| | | | | | - Trond Aasen
- Patologia Molecular Translacional, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron, Barcelona, Spain
| | - Andreas Brech
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, Oslo, Norway; Section for Physiology and Cell Biology, Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
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12
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Nielsen MS, van Opbergen CJM, van Veen TAB, Delmar M. The intercalated disc: a unique organelle for electromechanical synchrony in cardiomyocytes. Physiol Rev 2023; 103:2271-2319. [PMID: 36731030 PMCID: PMC10191137 DOI: 10.1152/physrev.00021.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
The intercalated disc (ID) is a highly specialized structure that connects cardiomyocytes via mechanical and electrical junctions. Although described in some detail by light microscopy in the 19th century, it was in 1966 that electron microscopy images showed that the ID represented apposing cell borders and provided detailed insight into the complex ID nanostructure. Since then, much has been learned about the ID and its molecular composition, and it has become evident that a large number of proteins, not all of them involved in direct cell-to-cell coupling via mechanical or gap junctions, reside at the ID. Furthermore, an increasing number of functional interactions between ID components are emerging, leading to the concept that the ID is not the sum of isolated molecular silos but an interacting molecular complex, an "organelle" where components work in concert to bring about electrical and mechanical synchrony. The aim of the present review is to give a short historical account of the ID's discovery and an updated overview of its composition and organization, followed by a discussion of the physiological implications of the ID architecture and the local intermolecular interactions. The latter will focus on both the importance of normal conduction of cardiac action potentials as well as the impact on the pathophysiology of arrhythmias.
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Affiliation(s)
- Morten S Nielsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chantal J M van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
| | - Toon A B van Veen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
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Huang SN, Pan YT, Zhou YP, Wang XZ, Mei MJ, Yang B, Li D, Zeng WB, Cheng S, Sun JY, Cheng H, Zhao F, Luo MH. Human Cytomegalovirus IE1 Impairs Neuronal Migration by Downregulating Connexin 43. J Virol 2023; 97:e0031323. [PMID: 37097169 PMCID: PMC10231247 DOI: 10.1128/jvi.00313-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/07/2023] [Indexed: 04/26/2023] Open
Abstract
Human cytomegalovirus (HCMV) is a leading cause of congenital birth defects. Though the underlying mechanisms remain poorly characterized, mouse models of congenital CMV infection have demonstrated that the neuronal migration process is damaged. In this study, we evaluated the effects of HCMV infection on connexin 43 (Cx43), a crucial adhesion molecule mediating neuronal migration. We show in multiple cellular models that HCMV infection downregulated Cx43 posttranslationally. Further analysis identified the immediate early protein IE1 as the viral protein responsible for the reduction of Cx43. IE1 was found to bind the Cx43 C terminus and promote Cx43 degradation through the ubiquitin-proteasome pathway. Deletion of the Cx43-binding site in IE1 rendered it incapable of inducing Cx43 degradation. We validated the IE1-induced loss of Cx43 in vivo by introducing IE1 into the fetal mouse brain. Noteworthily, ectopic IE1 expression induced cortical atrophy and neuronal migration defects. Several lines of evidence suggest that these damages result from decreased Cx43, and restoration of Cx43 levels partially rescued IE1-induced interruption of neuronal migration. Taken together, the results of our investigation reveal a novel mechanism of HCMV-induced neural maldevelopment and identify a potential intervention target. IMPORTANCE Congenital CMV (cCMV) infection causes neurological sequelae in newborns. Recent studies of cCMV pathogenesis in animal models reveal ventriculomegaly and cortical atrophy associated with impaired neural progenitor cell (NPC) proliferation and migration. In this study, we investigated the mechanisms underlying these NPC abnormalities. We show that Cx43, a critical adhesion molecule mediating NPC migration, is downregulated by HCMV infection in vitro and HCMV-IE1 in vivo. We provide evidence that IE1 interacts with the C terminus of Cx43 to promote its ubiquitination and consequent degradation through the proteasome. Moreover, we demonstrate that introducing IE1 into mouse fetal brains led to neuronal migration defects, which was associated with Cx43 reduction. Deletion of the Cx43-binding region in IE1 or ectopic expression of Cx43 rescued the IE1-induced migration defects in vivo. Our study provides insight into how cCMV infection impairs neuronal migration and reveals a target for therapeutic interventions.
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Affiliation(s)
- Sheng-Nan Huang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yu-Ting Pan
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yue-Peng Zhou
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy of Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, China
| | - Xian-Zhang Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Meng-Jie Mei
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bo Yang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- The Joint Center of Translational Precision Medicine, Guangzhou Institute of Pediatrics, Guangzhou Women and Children Medical Center, Guangzhou, China
| | - Dong Li
- Chinese Institute for Brain Research, Beijing, China
- School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Wen-Bo Zeng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Shuang Cheng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Jin-Yan Sun
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Han Cheng
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Fei Zhao
- Chinese Institute for Brain Research, Beijing, China
- School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Min-Hua Luo
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy of Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, China
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14
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Shimura D, Shaw RM. Live-cell imaging and analysis of actin-mediated mitochondrial fission. STAR Protoc 2023; 4:101958. [PMID: 36542522 PMCID: PMC9795527 DOI: 10.1016/j.xpro.2022.101958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/02/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Current approaches, such as fixed-cell imaging or single-snapshot imaging, are insufficient to capture cytoskeleton-mediated mitochondrial fission. Here, we present a protocol to capture actin-mediated mitochondrial fission using high-resolution time-lapse imaging. We describe steps starting from cell preparation and mitochondria labeling through to live-cell imaging and final analysis. This approach is also applicable for analysis of multiple cytoskeleton-mediated organelle events such as vesicle trafficking, membrane fusion, and endocytic events in live cells. For complete details on the use and execution of this protocol, please refer to Shimura et al. (2021).1.
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Affiliation(s)
- Daisuke Shimura
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA; Department of Surgery, School of Medicine, University of Utah, Salt Lake City, UT 84112, USA.
| | - Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA.
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15
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A new IRES-mediated truncated Cx32 isoform inhibits global mRNA translation to suppress glioblastoma. Biomed Pharmacother 2023; 161:114513. [PMID: 36931032 DOI: 10.1016/j.biopha.2023.114513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023] Open
Abstract
Glioblastoma (GBM) is the most lethal malignant primary brain tumor. Although multimodal therapy has been applied for GBM, the median survival time remains less than 16 months. Thus, better therapeutic targets in GBM are urgently needed. Herein, we first identified five new N-terminal-truncated Cx32 isoforms (GJB1-28k, GJB1-22k, GJB1-20k, GJB1-15k, and GJB1-13k) and further demonstrated that they were generated via cap-independent internal translation through internal ribosome entry sites (IRESs) in the coding sequence of GJB1 mRNA. Among these isoforms, GJB1-13k inhibited proliferation, promoted apoptosis, and limited cell cycle progression in GBM cells by inhibiting global mRNA translation. In vivo experiments further confirmed the antitumor activity of GJB1-13k against GBM cells. In addition, TSR3, a ribosomal maturation factor, was demonstrated to directly interact with GJB1-13k. Moreover, GBM cells with high TSR3 expression exhibited low sensitivity to GJB1-13k treatment, while GJB1-13k sensitivity was restored by TSR3 knockdown. Our work identifies a new IRES-mediated protein, GJB1-13k, and suggests that overexpression of GJB1-13k in GBM cells with low TSR3 expression or combined targeting of GJB1-13k and TSR3 in GBM cells with high TSR3 expression constitutes a potential therapeutic strategy for GBM.
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16
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Effects of electroacupuncture at Neiguan (PC6) on arrhythmia during myocardial infarction in a rat model of myocardial ischemia-reperfusion. JOURNAL OF ACUPUNCTURE AND TUINA SCIENCE 2023. [DOI: 10.1007/s11726-023-1352-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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17
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KCNH2 encodes a nuclear-targeted polypeptide that mediates hERG1 channel gating and expression. Proc Natl Acad Sci U S A 2023; 120:e2214700120. [PMID: 36626562 PMCID: PMC9934303 DOI: 10.1073/pnas.2214700120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
KCNH2 encodes hERG1, the voltage-gated potassium channel that conducts the rapid delayed rectifier potassium current (IKr) in human cardiac tissue. hERG1 is one of the first channels expressed during early cardiac development, and its dysfunction is associated with intrauterine fetal death, sudden infant death syndrome, cardiac arrhythmia, and sudden cardiac death. Here, we identified a hERG1 polypeptide (hERG1NP) that is targeted to the nuclei of immature cardiac cells, including human stem cell-derived cardiomyocytes (hiPSC-CMs) and neonatal rat cardiomyocytes. The nuclear hERG1NP immunofluorescent signal is diminished in matured hiPSC-CMs and absent from adult rat cardiomyocytes. Antibodies targeting distinct hERG1 channel epitopes demonstrated that the hERG1NP signal maps to the hERG1 distal C-terminal domain. KCNH2 deletion using CRISPR simultaneously abolished IKr and the hERG1NP signal in hiPSC-CMs. We then identified a putative nuclear localization sequence (NLS) within the distal hERG1 C-terminus, 883-RQRKRKLSFR-892. Interestingly, the distal C-terminal domain was targeted almost exclusively to the nuclei when overexpressed HEK293 cells. Conversely, deleting the NLS from the distal peptide abolished nuclear targeting. Similarly, blocking α or β1 karyopherin activity diminished nuclear targeting. Finally, overexpressing the putative hERG1NP peptide in the nuclei of HEK cells significantly reduced hERG1a current density, compared to cells expressing the NLS-deficient hERG1NP or GFP. These data identify a developmentally regulated polypeptide encoded by KCNH2, hERG1NP, whose presence in the nucleus indirectly modulates hERG1 current magnitude and kinetics.
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Kou Y, Sun Q, Zhu R, Lin Z, Li Z, Xu H, Feng X, Liu Y. Dioscin induces M1 macrophage polarization through Connexin-43 Channels in Tumor-associated-macrophages-mediated melanoma metastasis. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 109:154559. [PMID: 36610151 DOI: 10.1016/j.phymed.2022.154559] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 11/01/2022] [Accepted: 11/19/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Tumor-associated macrophages (TAMs) are important constituent parts of tumor microenvironment that connected with tumor metastasis in melanoma. Connexin 43 (Cx43) was expressed in all the immune cells which modulated different aspects of immune response. However, the concrete molecular mechanism maintains unclear. PURPOSE The study aimed to find a natural drug monomer effectively reversed the polarity of tumor-associated macrophages inhibiting melanoma metastasis and improving survival time. METHODS Flow cytometry was used to determine the effects of dioscin on the macrophage phenotype. Western bolt and ELISA were performed to explore the underlying mechanism of dioscin and a co-culture experiment in vitro was applied to assess the role of dioscin on TAMs-mediated melanoma proliferation, invasion and migration. Moreover, in vivo melanoma metastasis models were established for examining effects of dioscin on TAMs-mediated melanoma metastasis. RESULTS Dioscin repolarized macrophages from M2 towards M1-like phenotype. Dioscin suppressed M2-like phenotype macrophages through enhanced the expression and transport function of Cx43. Furthermore, the stimulation IFN-γ/STAT1 pathway and suppression IL-4/JAK2/STAT3 pathway were major mechanism of dioscin. Importantly, dioscin suppressed Cx43G21R mutation TAMs induced proliferation, invasion, migration and metastasis of melanoma cells. It worthily noting that dioscin ameliorated tumor-associated-macrophages-mediated melanoma metastasis in vitro and vivo. CONCLUSION Dioscin re-polarized macrophages from M2 to M1 phenotype through activation of Cx43-gap-junction-intercellular-communications (Cx43-GJs)/IFN-γ/STAT1 pathway and inhibition of Cx43-GJs/IL-4/JAK2/STAT3 suppressing migration, invasion and metastasis of melanoma, which provided a theoretical and experimental basis for treating melanoma metastasis.
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Affiliation(s)
- Yu Kou
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225000, Jiangsu, China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225000, Jiangsu, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medcine for Prevention and Treatment of Senile Diseases, Medical College of Yangzhou University, Yangzhou 225000, Jiangsu, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225000, Jiangsu, China.
| | - Qidi Sun
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225000, Jiangsu, China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225000, Jiangsu, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medcine for Prevention and Treatment of Senile Diseases, Medical College of Yangzhou University, Yangzhou 225000, Jiangsu, China
| | - Rentao Zhu
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225000, Jiangsu, China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225000, Jiangsu, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medcine for Prevention and Treatment of Senile Diseases, Medical College of Yangzhou University, Yangzhou 225000, Jiangsu, China
| | - Zhijie Lin
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225000, Jiangsu, China
| | - Zhuoqun Li
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225000, Jiangsu, China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225000, Jiangsu, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medcine for Prevention and Treatment of Senile Diseases, Medical College of Yangzhou University, Yangzhou 225000, Jiangsu, China
| | - Hairong Xu
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225000, Jiangsu, China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225000, Jiangsu, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medcine for Prevention and Treatment of Senile Diseases, Medical College of Yangzhou University, Yangzhou 225000, Jiangsu, China
| | - Xuan Feng
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225000, Jiangsu, China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225000, Jiangsu, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medcine for Prevention and Treatment of Senile Diseases, Medical College of Yangzhou University, Yangzhou 225000, Jiangsu, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225000, Jiangsu, China
| | - Yanqing Liu
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225000, Jiangsu, China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225000, Jiangsu, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medcine for Prevention and Treatment of Senile Diseases, Medical College of Yangzhou University, Yangzhou 225000, Jiangsu, China.
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Abstract
Gap junctions, comprising connexin proteins, create conduits directly coupling the cytoplasms of adjacent cells. Expressed in essentially all tissues, dynamic gap junction structures enable the exchange of small molecules including ions and second messengers, and are central to maintenance of homeostasis and synchronized excitability. With such diverse and critical roles throughout the body, it is unsurprising that alterations to gap junction and/or connexin expression and function underlie a broad array of age-related pathologies. From neurological dysfunction to cardiac arrhythmia and bone loss, it is hard to identify a human disease state that does not involve reduced, or in some cases inappropriate, intercellular communication to affect organ function. With a complex life cycle encompassing several key regulatory steps, pathological gap junction remodeling during ageing can arise from alterations in gene expression, translation, intracellular trafficking, and posttranslational modification of connexins. Connexin proteins are now known to "moonlight" and perform a variety of non-junctional functions in the cell, independent of gap junctions. Furthermore, connexin "hemichannels" on the cell surface can communicate with the extracellular space without ever coupling to an adjacent cell to form a gap junction channel. This chapter will focus primarily on gap junctions in ageing, but such non-junctional connexin functions will be referred to where appropriate and the full spectrum of connexin biology should be noted as potentially causative/contributing to some findings in connexin knockout animals, for example.
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Affiliation(s)
- Michael J Zeitz
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA.,FBRI Center for Vascular and Heart Research, Roanoke, VA, USA
| | - James W Smyth
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA. .,FBRI Center for Vascular and Heart Research, Roanoke, VA, USA. .,Department of Biological Sciences, College of Science, Virginia Tech, Blacksburg, VA, USA. .,Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA.
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Whisenant CC, Shaw RM. Internal translation of Gja1 (Connexin43) to produce GJA1-20k: Implications for arrhythmia and ischemic-preconditioning. Front Physiol 2022; 13:1058954. [PMID: 36569758 PMCID: PMC9768480 DOI: 10.3389/fphys.2022.1058954] [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: 09/30/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
Internal translation is a form of post-translation modification as it produces different proteins from one mRNA molecule by beginning translation at a methionine coding triplet downstream of the first methionine. Internal translation can eliminate domains of proteins that otherwise restrict movement or activity, thereby creating profound functional diversity. Connexin43 (Cx43), encoded by the gene Gja1, is the main gap junction protein necessary for propagating action potentials between adjacent cardiomyocytes. Gja1 can be internally translated to produce a peptide 20 kD in length named GJA1-20k. This review focuses on the role of GJA1-20k in maintaining cardiac electrical rhythm as well as in ischemic preconditioning (IPC). Connexin43 is the only ion channel we are aware that has been reported to be subject to internal translation. We expect many other ion channels also undergo internal translation. The exploration of post-translational modification of ion channels, and in particular of internal translation, has the potential to greatly increase our understanding of both canonical and non-canonical ion channel biology.
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21
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Falleni A, Moscato S, Fulvio G, Polizzi E, Bernardeschi M, Bianchi F, Donati V, Cabiati M, Ippolito C, Del Ry S, Baldini C, Mattii L. Connexin Expression in Human Minor Salivary Glands: An Immunohistochemical Microscopy Study. Molecules 2022; 27:molecules27185926. [PMID: 36144660 PMCID: PMC9505306 DOI: 10.3390/molecules27185926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/02/2022] [Accepted: 09/08/2022] [Indexed: 11/25/2022] Open
Abstract
Connexins (Cxs) are transmembrane proteins involved in the formation of hemichannels and gap junctions (GJs). GJs are involved in various physiological functions, including secretion in glandular tissue. It has been demonstrated that Cx26, Cx32, and Cx43 are mainly expressed in glands, but no data are available in human salivary glands to date. The aim of our study was to investigate the presence and the localization of Cxs in human minor labial salivary glands. Immunofluorescence and immunoelectron microscopy were employed to evaluate the Cx26, Cx32, and Cx43 protein in human labial salivary gland biopsies (hLSGBs). RT-PCR was also used to detect their mRNA expression. Cx expression was found at both the mRNA and protein levels in all hLSGBs analysed. Cxs were observed at the level of the duct and acinar cells, as well as in myoepithelial cells. The localization of the three Cx types was very similar, suggesting colocalization of these Cxs in the same connexons. These results demonstrated the presence of Cxs in human salivary glands for the first time. Moreover, the few samples with primary Sjögren’s Syndrome analysed only by immunofluorescence showed an alteration of the Cx expression, indicating that these proteins could be involved in salivary gland dysfunctions.
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Affiliation(s)
- Alessandra Falleni
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
- Correspondence: (A.F.); (L.M.); Tel.: +39-050-221-9106 (A.F.); +39-050-221-8615 (L.M.)
| | - Stefania Moscato
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Giovanni Fulvio
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Enza Polizzi
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | | | - Francesco Bianchi
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Valentina Donati
- Pathological Anatomy Unit, Azienda Ospedaliero-Universitaria Pisana, 56126 Pisa, Italy
| | - Manuela Cabiati
- Institute of Clinical Physiology (IFC), National Research Council (CNR), 56124 Pisa, Italy
| | - Chiara Ippolito
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Silvia Del Ry
- Institute of Clinical Physiology (IFC), National Research Council (CNR), 56124 Pisa, Italy
| | - Chiara Baldini
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Letizia Mattii
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
- Correspondence: (A.F.); (L.M.); Tel.: +39-050-221-9106 (A.F.); +39-050-221-8615 (L.M.)
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22
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Jones JC, Bodenstine TM. Connexins and Glucose Metabolism in Cancer. Int J Mol Sci 2022; 23:ijms231710172. [PMID: 36077565 PMCID: PMC9455984 DOI: 10.3390/ijms231710172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Connexins are a family of transmembrane proteins that regulate diverse cellular functions. Originally characterized for their ability to mediate direct intercellular communication through the formation of highly regulated membrane channels, their functions have been extended to the exchange of molecules with the extracellular environment, and the ability to modulate numerous channel-independent effects on processes such as motility and survival. Notably, connexins have been implicated in cancer biology for their context-dependent roles that can both promote or suppress cancer cell function. Moreover, connexins are able to mediate many aspects of cellular metabolism including the intercellular coupling of nutrients and signaling molecules. During cancer progression, changes to substrate utilization occur to support energy production and biomass accumulation. This results in metabolic plasticity that promotes cell survival and proliferation, and can impact therapeutic resistance. Significant progress has been made in our understanding of connexin and cancer biology, however, delineating the roles these multi-faceted proteins play in metabolic adaptation of cancer cells is just beginning. Glucose represents a major carbon substrate for energy production, nucleotide synthesis, carbohydrate modifications and generation of biosynthetic intermediates. While cancer cells often exhibit a dependence on glycolytic metabolism for survival, cellular reprogramming of metabolic pathways is common when blood perfusion is limited in growing tumors. These metabolic changes drive aggressive phenotypes through the acquisition of functional traits. Connections between glucose metabolism and connexin function in cancer cells and the surrounding stroma are now apparent, however much remains to be discovered regarding these relationships. This review discusses the existing evidence in this area and highlights directions for continued investigation.
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Hamledari H, Asghari P, Jayousi F, Aguirre A, Maaref Y, Barszczewski T, Ser T, Moore E, Wasserman W, Klein Geltink R, Teves S, Tibbits GF. Using human induced pluripotent stem cell-derived cardiomyocytes to understand the mechanisms driving cardiomyocyte maturation. Front Cardiovasc Med 2022; 9:967659. [PMID: 36061558 PMCID: PMC9429949 DOI: 10.3389/fcvm.2022.967659] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/28/2022] [Indexed: 11/13/2022] Open
Abstract
Cardiovascular diseases are the leading cause of mortality and reduced quality of life globally. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) provide a personalized platform to study inherited heart diseases, drug-induced cardiac toxicity, and cardiac regenerative therapy. However, the immaturity of CMs obtained by current strategies is a major hurdle in utilizing hiPSC-CMs at their fullest potential. Here, the major findings and limitations of current maturation methodologies to enhance the utility of hiPSC-CMs in the battle against a major source of morbidity and mortality are reviewed. The most recent knowledge of the potential signaling pathways involved in the transition of fetal to adult CMs are assimilated. In particular, we take a deeper look on role of nutrient sensing signaling pathways and the potential role of cap-independent translation mediated by the modulation of mTOR pathway in the regulation of cardiac gap junctions and other yet to be identified aspects of CM maturation. Moreover, a relatively unexplored perspective on how our knowledge on the effects of preterm birth on cardiovascular development can be actually utilized to enhance the current understanding of CM maturation is examined. Furthermore, the interaction between the evolving neonatal human heart and brown adipose tissue as the major source of neonatal thermogenesis and its endocrine function on CM development is another discussed topic which is worthy of future investigation. Finally, the current knowledge regarding transcriptional mediators of CM maturation is still limited. The recent studies have produced the groundwork to better understand CM maturation in terms of providing some of the key factors involved in maturation and development of metrics for assessment of maturation which proves essential for future studies on in vitro PSC-CMs maturation.
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Affiliation(s)
- Homa Hamledari
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Parisa Asghari
- Department of Cellular and Physiological Sciences, University of British Colombia, Vancouver, BC, Canada
| | - Farah Jayousi
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Alejandro Aguirre
- Department of Medical Genetics, University of British Colombia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Yasaman Maaref
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Tiffany Barszczewski
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Terri Ser
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, University of British Colombia, Vancouver, BC, Canada
| | - Edwin Moore
- Department of Cellular and Physiological Sciences, University of British Colombia, Vancouver, BC, Canada
| | - Wyeth Wasserman
- Department of Medical Genetics, University of British Colombia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Ramon Klein Geltink
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, University of British Colombia, Vancouver, BC, Canada
| | - Sheila Teves
- Department of Biochemistry and Molecular Biology, University of British Colombia, Vancouver, BC, Canada
| | - Glen F. Tibbits
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
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Strimaityte D, Tu C, Yanez A, Itzhaki I, Wu H, Wu JC, Yang H. Contractility and Calcium Transient Maturation in the Human iPSC-Derived Cardiac Microfibers. ACS APPLIED MATERIALS & INTERFACES 2022; 14:35376-35388. [PMID: 35901275 PMCID: PMC9780031 DOI: 10.1021/acsami.2c07326] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are considered immature in the sarcomere organization, contractile machinery, calcium transient, and transcriptome profile, which prevent them from further applications in modeling and studying cardiac development and disease. To improve the maturity of hiPSC-CMs, here, we engineered the hiPSC-CMs into cardiac microfibers (iCMFs) by a stencil-based micropatterning method, which enables the hiPSC-CMs to be aligned in an end-to-end connection for prolonged culture on the hydrogel of physiological stiffness. A series of characterization approaches were performed to evaluate the maturation in iCMFs on both structural and functional levels, including immunohistochemistry, calcium transient, reverse-transcription quantitative PCR, cardiac contractility, and electrical pacing analysis. Our results demonstrate an improved cardiac maturation of hiPSC-CMs in iCMFs compared to micropatterned or random single hiPSC-CMs and hiPSC-CMs in a random cluster at the same cell number of iCMFs. We found an increased sarcomere length, better regularity and alignment of sarcomeres, enhanced contractility, matured calcium transient, and T-tubule formation and improved adherens junction and gap junction formation. The hiPSC-CMs in iCMFs showed a robust calcium cycling in response to the programmed and continuous electrical pacing from 0.5 to 7 Hz. Moreover, we generated the iCMFs with hiPSC-CMs with mutations in myosin-binding protein C (MYBPC3) to have a proof-of-concept of iCMFs in modeling cardiac hypertrophic phenotype. These findings suggest that the multipatterned iCMF connection of hiPSC-CMs boosts the cardiac maturation structurally and functionally, which will reveal the full potential of the application of hiPSC-CM models in disease modeling of cardiomyopathy and cardiac regenerative medicine.
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Affiliation(s)
- Dovile Strimaityte
- Department of Biomedical Engineering, University of North Texas, Denton, TX 76207, USA
| | - Chengyi Tu
- Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Apuleyo Yanez
- Department of Biomedical Engineering, University of North Texas, Denton, TX 76207, USA
| | - Ilanit Itzhaki
- Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haodi Wu
- Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Joseph C. Wu
- Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Huaxiao Yang
- Department of Biomedical Engineering, University of North Texas, Denton, TX 76207, USA
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Boengler K, Leybaert L, Ruiz-Meana M, Schulz R. Connexin 43 in Mitochondria: What Do We Really Know About Its Function? Front Physiol 2022; 13:928934. [PMID: 35860665 PMCID: PMC9289461 DOI: 10.3389/fphys.2022.928934] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/26/2022] [Indexed: 01/04/2023] Open
Abstract
Connexins are known for their ability to mediate cell-cell communication via gap junctions and also form hemichannels that pass ions and molecules over the plasma membrane when open. Connexins have also been detected within mitochondria, with mitochondrial connexin 43 (Cx43) being the best studied to date. In this review, we discuss evidence for Cx43 presence in mitochondria of cell lines, primary cells and organs and summarize data on its localization, import and phosphorylation status. We further highlight the influence of Cx43 on mitochondrial function in terms of respiration, opening of the mitochondrial permeability transition pore and formation of reactive oxygen species, and also address the presence of a truncated form of Cx43 termed Gja1-20k. Finally, the role of mitochondrial Cx43 in pathological conditions, particularly in the heart, is discussed.
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Affiliation(s)
- Kerstin Boengler
- Institute of Physiology, Justus-Liebig University, Giessen, Germany
| | - Luc Leybaert
- Department of Basic and Applied Medical Sciences—Physiology Group, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Marisol Ruiz-Meana
- Cardiovascular Diseases Research Group, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Barcelona, Spain
| | - Rainer Schulz
- Institute of Physiology, Justus-Liebig University, Giessen, Germany
- *Correspondence: Rainer Schulz,
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Qin X, Gao A, Hou X, Xu X, Chen L, Sun L, Hao Y, Shi Y. Connexins may play a critical role in cigarette smoke-induced pulmonary hypertension. Arch Toxicol 2022; 96:1609-1621. [PMID: 35344070 DOI: 10.1007/s00204-022-03274-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/02/2022] [Indexed: 11/02/2022]
Abstract
Pulmonary hypertension (PH) is a chronic progressive disease characterized by pulmonary vasoconstriction and remodeling. It causes a gradual increase in pulmonary vascular resistance leading to right-sided heart failure, and may be fatal. Chronic exposure to cigarette smoke (CS) is an essential risk factor for PH group 3; however, smoking continues to be prevalent and smoking cessation is reported to be difficult. A majority of smokers exhibit PH, which leads to a concomitant increase in the risk of mortality. The current treatments for PH group 3 focus on vasodilation and long-term oxygen supplementation, and fail to stop or reverse PH-associated continuous vascular remodeling. Recent studies have suggested that pulmonary vascular endothelial dysfunction induced by CS exposure may be an initial event in the natural history of PH, which in turn may be associated with abnormal alterations in connexin (Cx) expression. The relationship between Cx and CS-induced PH development has not yet been directly investigated. Therefore, this review will describe the roles of CS and Cx in the development of PH and discuss the related downstream pathways. We also discuss the possible role of Cx in CS-induced PH. It is hoped that this review may provide new perspectives for early intervention.
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Affiliation(s)
- Xiaojiang Qin
- School of Public Health, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, 030001, Shanxi, China.
- China Key Laboratory of Cellular Physiology (Shanxi Medical University), Ministry of Education, 56 Xinjian South Road, Taiyuan, 030001, Shanxi, China.
| | - Anqi Gao
- School of Public Health, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, 030001, Shanxi, China
| | - Xiaomin Hou
- Department of Pharmacology, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, 030001, Shanxi, China
- China Key Laboratory of Cellular Physiology (Shanxi Medical University), Ministry of Education, 56 Xinjian South Road, Taiyuan, 030001, Shanxi, China
| | - Xinrong Xu
- School of Public Health, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, 030001, Shanxi, China
| | - Liangjin Chen
- School of Public Health, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, 030001, Shanxi, China
| | - Lin Sun
- School of Public Health, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, 030001, Shanxi, China
| | - Yuxuan Hao
- School of Public Health, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, 030001, Shanxi, China
| | - Yiwei Shi
- Department of Respiratory and Critical Care Medicine, Shanxi Medical University Affiliated First Hospital, 85 Jiefang South Road, Taiyuan, 030001, Shanxi, China.
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Shimura D, Shaw RM. GJA1-20k and Mitochondrial Dynamics. Front Physiol 2022; 13:867358. [PMID: 35399255 PMCID: PMC8983841 DOI: 10.3389/fphys.2022.867358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/08/2022] [Indexed: 01/07/2023] Open
Abstract
Connexin 43 (Cx43) is the primary gap junction protein of mammalian heart ventricles and is encoded by the gene Gja1 which has a single coding exon and therefore cannot be spliced. We previously identified that Gja1 mRNA undergoes endogenous internal translation initiated at one of several internal AUG (M) start codons, generating N-terminal truncated protein isoforms that retain the C-terminus distal to the start site. GJA1-20k, whose translation initiates at mRNA M213, is usually the most abundant isoform in cells and greatly increases after ischemic and metabolic stress. GJA1-20k consists of a small segment of the last transmembrane domain and the complete C-terminus tail of Cx43, with a total size of about 20 kDa. The original role identified for GJA1-20k is as an essential subunit that facilitates the trafficking of full-length Cx43 hexameric hemichannels to cell-cell contacts, generating traditional gap junctions between adjacent cells facilitating, in cardiac muscle, efficient spread of electrical excitation. GJA1-20k deficient mice (generated by a M213L substitution in Gja1) suffer poor electrical coupling between cardiomycytes and arrhythmogenic sudden death two to 4 weeks after their birth. We recently identified that exogenous GJA1-20k expression also mimics the effect of ischemic preconditioning in mouse heart. Furthermore, GJA1-20k localizes to the mitochondrial outer membrane and induces a protective and DRP1 independent form of mitochondrial fission, preserving ATP production and generating less reactive oxygen species (ROS) under metabolic stress, providing powerful protection of myocardium to ischemic insult. In this manuscript, we focus on the detailed roles of GJA1-20k in mitochondria, and its interaction with the actin cytoskeleton.
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Connexin 43 Gene Ablation Does Not Alter Human Pluripotent Stem Cell Germ Lineage Specification. Biomolecules 2021; 12:biom12010015. [PMID: 35053163 PMCID: PMC8773696 DOI: 10.3390/biom12010015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 01/23/2023] Open
Abstract
During embryonic germ layer development, cells communicate with each other and their environment to ensure proper lineage specification and tissue development. Connexin (Cx) proteins facilitate direct cell–cell communication through gap junction channels. While previous reports suggest that gap junctional intercellular communication may contribute to germ layer formation, there have been limited comprehensive expression analyses or genetic ablation studies on Cxs during human pluripotent stem cell (PSC) germ lineage specification. We screened the mRNA profile and protein expression patterns of select human Cx isoforms in undifferentiated human induced pluripotent stem cells (iPSCs), and after directed differentiation into the three embryonic germ lineages: ectoderm, definitive endoderm, and mesoderm. Transcript analyses by qPCR revealed upregulation of Cx45 and Cx62 in iPSC-derived ectoderm; Cx45 in mesoderm; and Cx30.3, Cx31, Cx32, Cx36, Cx37, and Cx40 in endoderm relative to control human iPSCs. Generated Cx43 (GJA1) CRISPR-Cas9 knockout iPSCs successfully differentiated into cells of all three germ layers, suggesting that Cx43 is dispensable during directed iPSC lineage specification. Furthermore, qPCR screening of select Cx transcripts in our GJA1-/- iPSCs showed no significant Cx upregulation in response to the loss of Cx43 protein. Future studies will reveal possible compensation by additional Cxs, suggesting targets for future CRISPR-Cas9 ablation studies in human iPSC lineage specification.
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Zheng QL, Zhu HY, Xu X, Chu SF, Cui LY, Dong YX, Liu YJ, Zhan JH, Wang ZZ, Chen NH. Korean red ginseng alleviate depressive disorder by improving astrocyte gap junction function. JOURNAL OF ETHNOPHARMACOLOGY 2021; 281:114466. [PMID: 34332064 DOI: 10.1016/j.jep.2021.114466] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 06/28/2021] [Accepted: 07/25/2021] [Indexed: 06/13/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Korean red ginseng (KRG), a processed product of Panax ginseng C. A. Mey, show significant anti-depressive effect in clinic. However, its mechanism is still unclear. AIM OF THE STUDY Gap junction intercellular communication (GJIC) dysfunction is a potential pathogenesis of depression. Therefore, this study's objective is to investigate whether the antidepressant effect of KRG is related to GJIC. MATERIALS AND METHODS Rat were restraint 8 h every day for 28 consecutive days to prepare depression models, and meanwhile, rats were intragastrically administrated with normal saline, KRG solutions (25, 50 or 100 mg/kg) or fluoxetine (10 mg/kg) 1 h before stress. The behavioral performance was determined by forced swimming test, sucrose preference test and open field test. GJIC was determined by the Lucifer yellow (LY) diffusion distance in prelimb cortex (PLC). In addition, the level of Cx43, one of executors of GJIC, was tested by Western blot. To find out the protective effect of KRG against GJIC dysfunction directly, rats were intracranially injected with carbenoxolone (CBX, blocker of GJIC), and meanwhile normal saline, KRG (100 mg/kg) or fluoxetine (10 mg/kg) was administered daily. The behavioral performance of these rats was detected, and the LY localization injection PLC area was used to detect the gap junction function. RESULTS Chronic resistant stress (CRS) induced depressive symptoms, as manifested by prolonged immobility time in forced swimming test and decreased sucrose consumption ratio. Administration of KRG alleviated these depressive symptoms significantly. GJIC determination showed that KRG improved the LY diffusion and increased Cx43 level in prefrontal cortex (PFC) significantly, indicated that GJIC dysfunction was alleviated by the treatment of KRG. However, the astrocytes number was also increased by the treatment of KRG, which maybe alleviate depression-like symptoms by increasing the number of astrocytes rather than improving GJIC. Injection of CBX produced depressive symptoms and GJIC dysfunction, as manifested by decreased sucrose consumption ratio and prolonged immobility time in forced swimming test, but no astrocytes number changes, KRG also reversed depressive symptoms and GJIC dysfunction, suggested that the improvement of depressive-like symptoms was improved by GJIC. CONCLUSIONS KRG alleviate depressive disorder by improving astrocytic gap junction function.
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Affiliation(s)
- Qing-Lian Zheng
- Institute for Brain Research and Rehabilitation (IBRR), South China Normal University (SCNU), Guangzhou, 510631, China.
| | - Hao-Yu Zhu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Xin Xu
- Institute for Brain Research and Rehabilitation (IBRR), South China Normal University (SCNU), Guangzhou, 510631, China.
| | - Shi-Feng Chu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Li-Yuan Cui
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Yi-Xiao Dong
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Ying-Jiao Liu
- Hunan University of Chinese Medicine & Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, Changsha 410208 Hunan, China.
| | - Jia-Hong Zhan
- DME Center, Clinical Pharmacology Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
| | - Zhen-Zhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Nai-Hong Chen
- Institute for Brain Research and Rehabilitation (IBRR), South China Normal University (SCNU), Guangzhou, 510631, China; State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China; Hunan University of Chinese Medicine & Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, Changsha 410208 Hunan, China; DME Center, Clinical Pharmacology Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
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Subcellular Localization of Connexin 26 in Cardiomyocytes and in Cardiomyocyte-Derived Extracellular Vesicles. Molecules 2021; 26:molecules26216726. [PMID: 34771134 PMCID: PMC8587102 DOI: 10.3390/molecules26216726] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/26/2021] [Accepted: 11/03/2021] [Indexed: 12/13/2022] Open
Abstract
Connexins (Cxs) are a family of membrane-spanning proteins, expressed in vertebrates and named according to their molecular weight. They are involved in tissue homeostasis, and they function by acting at several communication levels. Cardiac Cxs are responsible for regular heart function and, among them, Cx26 and Cx43 are widely expressed throughout the heart. Cx26 is present in vessels, as well as in cardiomyocytes, and its localization is scattered all over the cell aside from at the intercalated discs as is the case for the other cardiac Cxs. However, having been found in cardiomyocytes only recently, both its subcellular localization and its functional characterization in cardiomyocytes remain poorly understood. Therefore, in this study we aimed to obtain further data on the localization of Cx26 at the subcellular level. Our TEM immunogold analyses were performed on rat heart ventricles and differentiated H9c2 cardiac cell sections as well as on differentiated H9c2 derived extracellular vesicles. The results confirmed the absence of Cx26 at intercalated discs and showed the presence of Cx26 at the level of different subcellular compartments. The peculiar localization at the level of extracellular vesicles suggested a specific role for cardiac Cx26 in inter-cellular communication in an independent gap junction manner.
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Shimura D, Nuebel E, Baum R, Valdez SE, Xiao S, Warren JS, Palatinus JA, Hong T, Rutter J, Shaw RM. Protective mitochondrial fission induced by stress-responsive protein GJA1-20k. eLife 2021; 10:69207. [PMID: 34608863 PMCID: PMC8492060 DOI: 10.7554/elife.69207] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 09/09/2021] [Indexed: 12/13/2022] Open
Abstract
The Connexin43 gap junction gene GJA1 has one coding exon, but its mRNA undergoes internal translation to generate N-terminal truncated isoforms of Connexin43 with the predominant isoform being only 20 kDa in size (GJA1-20k). Endogenous GJA1-20k protein is not membrane bound and has been found to increase in response to ischemic stress, localize to mitochondria, and mimic ischemic preconditioning protection in the heart. However, it is not known how GJA1-20k benefits mitochondria to provide this protection. Here, using human cells and mice, we identify that GJA1-20k polymerizes actin around mitochondria which induces focal constriction sites. Mitochondrial fission events occur within about 45 s of GJA1-20k recruitment of actin. Interestingly, GJA1-20k mediated fission is independent of canonical Dynamin-Related Protein 1 (DRP1). We find that GJA1-20k-induced smaller mitochondria have decreased reactive oxygen species (ROS) generation and, in hearts, provide potent protection against ischemia-reperfusion injury. The results indicate that stress responsive internally translated GJA1-20k stabilizes polymerized actin filaments to stimulate non-canonical mitochondrial fission which limits ischemic-reperfusion induced myocardial infarction.
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Affiliation(s)
- Daisuke Shimura
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, United States
| | - Esther Nuebel
- Howard Hughes Medical Institute, University of Utah, Salt Lake City, United States.,Department of Biochemistry, University of Utah, Salt Lake City, United States.,Biomedical Sciences, Noorda College of Osteopathic Medicine, Provo, United States
| | - Rachel Baum
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, United States
| | - Steven E Valdez
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, United States
| | - Shaohua Xiao
- Department of Neurology, University of California at Los Angeles, Los Angeles, United States
| | - Junco S Warren
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, United States
| | - Joseph A Palatinus
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, United States
| | - TingTing Hong
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, United States.,Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, United States.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, United States
| | - Jared Rutter
- Howard Hughes Medical Institute, University of Utah, Salt Lake City, United States.,Department of Biochemistry, University of Utah, Salt Lake City, United States.,Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, United States
| | - Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, United States
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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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Chu Q, Xiao Y, Song X, Kang YJ. Extracellular matrix remodeling is associated with the survival of cardiomyocytes in the subendocardial region of the ischemic myocardium. Exp Biol Med (Maywood) 2021; 246:2579-2588. [PMID: 34515546 DOI: 10.1177/15353702211042020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A significant amount of cardiomyocytes in subendocardial region survive from ischemic insults. In order to understand the mechanism by which these cardiomyocytes survive, the present study was undertaken to examine changes in these surviving cardiomyocytes and their extracellular matrix. Male C57BL/6 mice aged 8-12 weeks old were subjected to a permanent left anterior descending coronary artery ligation to induce ischemic injury. The hearts were collected at 1, 4, 7, or 28 days after the surgery and examined by histology. At day 1 after left anterior descending ligation, there was a significant loss of cardiomyocytes through apoptosis, but a proportion of cardiomyocytes were surviving in the subendocardial region. The surviving cardiomyocytes were gradually changed from rod-shaped to round-shaped, and appeared disconnected. Connexin 43, an important gap junction protein, was significantly decreased, and collagen I and III deposition was significantly increased in the extracellular matrix. Furthermore, lysyl oxidase, a copper-dependent amine oxidase catalyzing the cross-linking of collagens, was significantly increased in the extracellular matrix, paralleled with the surviving cardiomyocytes. Inhibition of lysyl oxidase activity reduced the number of surviving cardiomyocytes. Thus, the extracellular matrix remodeling is correlated with the deformation of cardiomyocytes, and the electrical disconnection between the surviving cardiomyocytes due to connexin 43 depletion and the increase in lysyl oxidase would help these deformed cardiomyocytes survive under ischemic conditions.
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Affiliation(s)
- Qing Chu
- Regenerative Medicine Research Center, Sichuan University West China Hospital, Chengdu, Sichuan 610041, China
| | - Ying Xiao
- Regenerative Medicine Research Center, Sichuan University West China Hospital, Chengdu, Sichuan 610041, China
| | - Xin Song
- Regenerative Medicine Research Center, Sichuan University West China Hospital, Chengdu, Sichuan 610041, China
| | - Y James Kang
- Regenerative Medicine Research Center, Sichuan University West China Hospital, Chengdu, Sichuan 610041, China.,Tennessee Institute of Regenerative Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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34
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Kléber AG, Jin Q. Coupling between cardiac cells-An important determinant of electrical impulse propagation and arrhythmogenesis. ACTA ACUST UNITED AC 2021; 2:031301. [PMID: 34296210 DOI: 10.1063/5.0050192] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/09/2021] [Indexed: 01/30/2023]
Abstract
Cardiac arrhythmias are an important cause of sudden cardiac death-a devastating manifestation of many underlying causes, such as heart failure and ischemic heart disease leading to ventricular tachyarrhythmias and ventricular fibrillation, and atrial fibrillation causing cerebral embolism. Cardiac electrical propagation is a main factor in the initiation and maintenance of cardiac arrhythmias. In the heart, gap junctions are the basic unit at the cellular level that host intercellular low-resistance channels for the diffusion of ions and small regulatory molecules. The dual voltage clamp technique enabled the direct measurement of electrical conductance between cells and recording of single gap junction channel openings. The rapid turnover of gap junction channels at the intercalated disk implicates a highly dynamic process of trafficking and internalization of gap junction connexons. Recently, non-canonical roles of gap junction proteins have been discovered in mitochondria function, cytoskeletal organization, trafficking, and cardiac rescue. At the tissue level, we explain the concepts of linear propagation and safety factor based on the model of linear cellular structure. Working myocardium is adequately represented as a discontinuous cellular network characterized by cellular anisotropy and connective tissue heterogeneity. Electrical propagation in discontinuous cellular networks reflects an interplay of three main factors: cell-to-cell electrical coupling, flow of electrical charge through the ion channels, and the microscopic tissue structure. This review provides a state-of-the-art update of the cardiac gap junction channels and their role in cardiac electrical impulse propagation and highlights a combined approach of genetics, cell biology, and physics in modern cardiac electrophysiology.
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Affiliation(s)
- André G Kléber
- Department of Pathology, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Qianru Jin
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, Massachusetts 02134, USA
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Connexins in the Heart: Regulation, Function and Involvement in Cardiac Disease. Int J Mol Sci 2021; 22:ijms22094413. [PMID: 33922534 PMCID: PMC8122935 DOI: 10.3390/ijms22094413] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/12/2021] [Accepted: 04/20/2021] [Indexed: 12/20/2022] Open
Abstract
Connexins are a family of transmembrane proteins that play a key role in cardiac physiology. Gap junctional channels put into contact the cytoplasms of connected cardiomyocytes, allowing the existence of electrical coupling. However, in addition to this fundamental role, connexins are also involved in cardiomyocyte death and survival. Thus, chemical coupling through gap junctions plays a key role in the spreading of injury between connected cells. Moreover, in addition to their involvement in cell-to-cell communication, mounting evidence indicates that connexins have additional gap junction-independent functions. Opening of unopposed hemichannels, located at the lateral surface of cardiomyocytes, may compromise cell homeostasis and may be involved in ischemia/reperfusion injury. In addition, connexins located at non-canonical cell structures, including mitochondria and the nucleus, have been demonstrated to be involved in cardioprotection and in regulation of cell growth and differentiation. In this review, we will provide, first, an overview on connexin biology, including their synthesis and degradation, their regulation and their interactions. Then, we will conduct an in-depth examination of the role of connexins in cardiac pathophysiology, including new findings regarding their involvement in myocardial ischemia/reperfusion injury, cardiac fibrosis, gene transcription or signaling regulation.
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Identification and classification of innexin gene transcripts in the central nervous system of the terrestrial slug Limax valentianus. PLoS One 2021; 16:e0244902. [PMID: 33857131 PMCID: PMC8049302 DOI: 10.1371/journal.pone.0244902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/09/2021] [Indexed: 12/20/2022] Open
Abstract
Intercellular gap junction channels and single-membrane channels have been reported to regulate electrical synapse and the brain function. Innexin is known as a gap junction-related protein in invertebrates and is involved in the formation of intercellular gap junction channels and single-cell membrane channels. Multiple isoforms of innexin protein in each species enable the precise regulation of channel function. In molluscan species, sequence information of innexins is still limited and the sequences of multiple innexin isoforms have not been classified. This study examined the innexin transcripts expressed in the central nervous system of the terrestrial slug Limax valentianus and identified 16 transcripts of 12 innexin isoforms, including the splicing variants. We performed phylogenetic analysis and classified the isoforms with other molluscan innexin sequences. Next, the phosphorylation, N-glycosylation, and S-nitrosylation sites were predicted to characterize the innexin isoforms. Further, we identified 16 circular RNA sequences of nine innexin isoforms in the central nervous system of Limax. The identification and classification of molluscan innexin isoforms provided novel insights for understanding the regulatory mechanism of innexin in this phylum.
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Fu YL, Tao L, Peng FH, Zheng NZ, Lin Q, Cai SY, Wang Q. GJA1-20k attenuates Ang II-induced pathological cardiac hypertrophy by regulating gap junction formation and mitochondrial function. Acta Pharmacol Sin 2021; 42:536-549. [PMID: 32620936 PMCID: PMC8115281 DOI: 10.1038/s41401-020-0459-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 06/07/2020] [Indexed: 02/06/2023] Open
Abstract
Cardiac hypertrophy (CH) is characterized by an increase in cardiomyocyte size, and is the most common cause of cardiac-related sudden death. A decrease in gap junction (GJ) coupling and mitochondrial dysfunction are important features of CH, but the mechanisms of decreased coupling and energy impairment are poorly understood. It has been reported that GJA1-20k has a strong tropism for mitochondria and is required for the trafficking of connexin 43 (Cx43) to cell-cell borders. In this study, we investigated the effects of GJA1-20k on Cx43 GJ coupling and mitochondrial function in the pathogenesis of CH. We performed hematoxylin-eosin (HE) and Masson staining, and observed significant CH in 18-week-old male spontaneously hypertensive rats (SHRs) compared to age-matched normotensive Wistar-Kyoto (WKY) rats. In cardiomyocytes from SHRs, the levels of Cx43 at the intercalated disc (ID) and the expression of GJA1-20k were significantly reduced, whereas JAK-STAT signaling was activated. Furthermore, the SHR rats displayed suppressed mitochondrial GJA1-20k and mitochondrial biogenesis. Administration of valsartan (10 mg· [Formula: see text] d-1, i.g., for 8 weeks) prevented all of these changes. In neonatal rat cardiomyocytes (NRCMs), overexpression of GJA1-20k attenuated Ang II-induced cardiomyocyte hypertrophy and caused elevated levels of GJ coupling at the cell-cell borders. Pretreatment of NRCMs with the Jak2 inhibitor AG490 (10 µM) blocked Ang II-induced reduction in GJA1-20k expression and Cx43 gap junction formation; knockdown of Jak2 in NRCMs significantly lessened Ang II-induced cardiomyocyte hypertrophy and normalized GJA1-20k expression and Cx43 gap junction formation. Overexpression of GJA1-20k improved mitochondrial membrane potential and respiration and lowered ROS production in Ang II-induced cardiomyocyte hypertrophy. These results demonstrate the importance of GJA1-20k in regulating gap junction formation and mitochondrial function in Ang II-induced cardiomyocyte hypertrophy, thus providing a novel therapeutic strategy for patients with cardiomyocyte hypertrophy.
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Affiliation(s)
- Yi-le Fu
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Liang Tao
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Fu-Hua Peng
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Ning-Ze Zheng
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Qing Lin
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Shao-Yi Cai
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Qin Wang
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.
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Garbern JC, Lee RT. Mitochondria and metabolic transitions in cardiomyocytes: lessons from development for stem cell-derived cardiomyocytes. Stem Cell Res Ther 2021; 12:177. [PMID: 33712058 PMCID: PMC7953594 DOI: 10.1186/s13287-021-02252-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/28/2021] [Indexed: 12/13/2022] Open
Abstract
Current methods to differentiate cardiomyocytes from human pluripotent stem cells (PSCs) inadequately recapitulate complete development and result in PSC-derived cardiomyocytes (PSC-CMs) with an immature or fetal-like phenotype. Embryonic and fetal development are highly dynamic periods during which the developing embryo or fetus is exposed to changing nutrient, oxygen, and hormone levels until birth. It is becoming increasingly apparent that these metabolic changes initiate developmental processes to mature cardiomyocytes. Mitochondria are central to these changes, responding to these metabolic changes and transitioning from small, fragmented mitochondria to large organelles capable of producing enough ATP to support the contractile function of the heart. These changes in mitochondria may not simply be a response to cardiomyocyte maturation; the metabolic signals that occur throughout development may actually be central to the maturation process in cardiomyocytes. Here, we review methods to enhance maturation of PSC-CMs and highlight evidence from development indicating the key roles that mitochondria play during cardiomyocyte maturation. We evaluate metabolic transitions that occur during development and how these affect molecular nutrient sensors, discuss how regulation of nutrient sensing pathways affect mitochondrial dynamics and function, and explore how changes in mitochondrial function can affect metabolite production, the cell cycle, and epigenetics to influence maturation of cardiomyocytes.
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Affiliation(s)
- Jessica C Garbern
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, 7 Divinity Ave, Cambridge, MA, 02138, USA
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Richard T Lee
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, 7 Divinity Ave, Cambridge, MA, 02138, USA.
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 75 Francis St, Boston, MA, 02115, USA.
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Zhao S, Sheng S, Wang Y, Ding L, Xu X, Xia X, Zheng JC. Astrocyte-derived extracellular vesicles: A double-edged sword in central nervous system disorders. Neurosci Biobehav Rev 2021; 125:148-159. [PMID: 33626395 DOI: 10.1016/j.neubiorev.2021.02.027] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 12/28/2020] [Accepted: 02/16/2021] [Indexed: 12/14/2022]
Abstract
Recent studies suggest that astrocytes released a great quantity of extracellular vesicles (AEVs) to communicate with other brain cells. Under pathological conditions, AEVs are widely associated with the pathogenesis of neurobiological diseases by horizontally transferring pathogenic factors to neighboring cells or peripheral immune cells. Their beneficial role is also evident by the fact that they are involved in neuroprotection and neuroregeneration through alleviating apoptosis, maintaining neuronal function, and repairing neural injuries. The strong association of AEVswith neurological disorders makes AEVs a promising target for disease diagnosis, treatment, and prevention. The identification of disease-specific cargos in AEVs isolated from the patients' biofluids suggests AEVs as an attractive platform for biomarker development. Furthermore, the inhibition of inflammatory/toxic AEV release and the preservation of neuroprotective AEV release have been considered as potential therapeutic strategies in CNS disorder treatment and prevention, respectively. Here, we summarize the biological roles of AEVs as pathological contributors, protective/regenerative factors, and potential diagnostic biomarkers and therapeutic targets for neurological disorders, with a focus on recent progresses and emerging concepts.
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Affiliation(s)
- Shu Zhao
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai 200072, China
| | - Shiyang Sheng
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai 200072, China
| | - Yi Wang
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai 200072, China
| | - Lu Ding
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai 200072, China
| | - Xiaonan Xu
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai 200072, China
| | - Xiaohuan Xia
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai 200072, China; Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital affiliated to Tongji University School of Medicine, Shanghai 200434, China.
| | - Jialin C Zheng
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai 200072, China; Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital affiliated to Tongji University School of Medicine, Shanghai 200434, China; Collaborative Innovation Center for Brain Science, Tongji University, Shanghai 200092, China; Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5930, USA.
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40
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Xiao S, Shimura D, Baum R, Hernandez DM, Agvanian S, Nagaoka Y, Katsumata M, Lampe PD, Kleber AG, Hong T, Shaw RM. Auxiliary trafficking subunit GJA1-20k protects connexin-43 from degradation and limits ventricular arrhythmias. J Clin Invest 2021; 130:4858-4870. [PMID: 32525845 DOI: 10.1172/jci134682] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 06/03/2020] [Indexed: 12/31/2022] Open
Abstract
Connexin-43 (Cx43) gap junctions provide intercellular coupling, which ensures rapid action potential propagation and synchronized heart contraction. Alterations in Cx43 localization and reductions in gap junction coupling occur in failing hearts, contributing to ventricular arrhythmias and sudden cardiac death. Recent reports have found that an internally translated Cx43 isoform, GJA1-20k, is an auxiliary subunit for the trafficking of Cx43 in heterologous expression systems. Here, we have created a mouse model by using CRISPR technology to mutate a single internal translation initiation site in Cx43 (M213L mutation), which generates full-length Cx43, but not GJA1-20k. We found that GJA1M213L/M213L mice had severely abnormal electrocardiograms despite preserved contractile function, reduced total Cx43, and reduced gap junctions, and they died suddenly at 2 to 4 weeks of age. Heterozygous GJA1M213L/WT mice survived to adulthood with increased ventricular ectopy. Biochemical experiments indicated that cytoplasmic Cx43 had a half-life that was 50% shorter than membrane-associated Cx43. Without GJA1-20k, poorly trafficked Cx43 was degraded. The data support that GJA1-20k, an endogenous entity translated independently of Cx43, is critical for Cx43 gap junction trafficking, maintenance of Cx43 protein, and normal electrical function of the mammalian heart.
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Affiliation(s)
- Shaohua Xiao
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA.,Department of Neurology, UCLA, Los Angeles, California, USA
| | - Daisuke Shimura
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA
| | - Rachel Baum
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Diana M Hernandez
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Sosse Agvanian
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Yoshiko Nagaoka
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.,Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Makoto Katsumata
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Paul D Lampe
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Andre G Kleber
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - TingTing Hong
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA
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41
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Boengler K, Rohrbach S, Weissmann N, Schulz R. Importance of Cx43 for Right Ventricular Function. Int J Mol Sci 2021; 22:ijms22030987. [PMID: 33498172 PMCID: PMC7863922 DOI: 10.3390/ijms22030987] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 11/16/2022] Open
Abstract
In the heart, connexins form gap junctions, hemichannels, and are also present within mitochondria, with connexin 43 (Cx43) being the most prominent connexin in the ventricles. Whereas the role of Cx43 is well established for the healthy and diseased left ventricle, less is known about the importance of Cx43 for the development of right ventricular (RV) dysfunction. The present article focusses on the importance of Cx43 for the developing heart. Furthermore, we discuss the expression and localization of Cx43 in the diseased RV, i.e., in the tetralogy of Fallot and in pulmonary hypertension, in which the RV is affected, and RV hypertrophy and failure occur. We will also introduce other Cx molecules that are expressed in RV and surrounding tissues and have been reported to be involved in RV pathophysiology. Finally, we highlight therapeutic strategies aiming to improve RV function in pulmonary hypertension that are associated with alterations of Cx43 expression and function.
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42
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Lyu QR, Yao P, Miano JM. Generating a CRISPR knockout mouse through a strong premature termination codon: a cautionary tale. J Biomed Res 2021; 35:174-178. [PMID: 33797417 PMCID: PMC8038525 DOI: 10.7555/jbr.34.20200106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Qing Rex Lyu
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA.,Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA.,Institute of Biomedicine and Health, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Peng Yao
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
| | - Joseph M Miano
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA.,Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
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43
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Shaw RM, Saffitz JE. A role for connexin-43 in Duchenne muscular dystrophy cardiomyopathy. J Clin Invest 2020; 130:1608-1610. [PMID: 32091412 DOI: 10.1172/jci135007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The cardiomyopathy of Duchenne muscular dystrophy (DMD) is an important cause of morbidity and mortality in affected males with this dreaded muscle disease. Previous studies have implicated changes in expression and subcellular localization of connexin-43 (Cx43), the major ventricular gap junction protein, in DMD cardiomyopathy. In this issue of the JCI, Himelman et al. explore how hypophosphorylation of Cx43 at a triplet of serine residues (S325/S328/S330) in the regulatory C-terminus contributes to multiple features of the cardiomyopathy phenotype. Using a mouse model of DMD cardiomyopathy in which phosphomimetic glutamic acids are substituted for serines at these residues in Cx43, Himelman et al. observed reduced gap junction remodeling and lateralization of Cx43 immunosignals, protection against isoproterenol-induced arrhythmias, and improved Ca2+ homeostasis. This study contributes to the understanding of pathologic Cx43 remodeling and encourages further research into developing strategic interventions to mitigate cardiac dysfunction and arrhythmias in DMD patients.
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Affiliation(s)
- Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA
| | - Jeffrey E Saffitz
- Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
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44
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Mulkearns-Hubert EE, Reizes O, Lathia JD. Connexins in Cancer: Jekyll or Hyde? Biomolecules 2020; 10:E1654. [PMID: 33321749 PMCID: PMC7764653 DOI: 10.3390/biom10121654] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 12/16/2022] Open
Abstract
The expression, localization, and function of connexins, the protein subunits that comprise gap junctions, are often altered in cancer. In addition to cell-cell coupling through gap junction channels, connexins also form hemichannels that allow communication between the cell and the extracellular space and perform non-junctional intracellular activities. Historically, connexins have been considered tumor suppressors; however, they can also serve tumor-promoting functions in some contexts. Here, we review the literature surrounding connexins in cancer cells in terms of specific connexin functions and propose that connexins function upstream of most, if not all, of the hallmarks of cancer. The development of advanced connexin targeting approaches remains an opportunity for the field to further interrogate the role of connexins in cancer phenotypes, particularly through the use of in vivo models. More specific modulators of connexin function will both help elucidate the functions of connexins in cancer and advance connexin-specific therapies in the clinic.
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Affiliation(s)
- Erin E. Mulkearns-Hubert
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (O.R.); (J.D.L.)
| | - Ofer Reizes
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (O.R.); (J.D.L.)
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College, Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Justin D. Lathia
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (O.R.); (J.D.L.)
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College, Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
- Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH, 44195, USA
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45
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Connexins-Therapeutic Targets in Cancers. Int J Mol Sci 2020; 21:ijms21239119. [PMID: 33266154 PMCID: PMC7730856 DOI: 10.3390/ijms21239119] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 12/11/2022] Open
Abstract
Connexins (Cx) are members of a protein family that forms intercellular channels localised in gap junction (GJ) plaques and single transmembrane channels called hemichannels. They participate in intercellular communication or communication between the intracellular and extracellular environments. Connexins affect cell homeostasis, growth and differentiation by enabling the exchange of metabolites or by interfering with various signalling pathways. Alterations in the functionality and the expression of connexins have been linked to the occurrence of many diseases. Connexins have been already linked to cancers, cardiac and brain disorders, chronic lung and kidney conditions and wound healing processes. Connexins have been shown either to suppress cancer tumour growth or to increase tumorigenicity by promoting cancer cell growth, migration and invasiveness. A better understanding of the complexity of cancer biology related to connexins and intercellular communication could result in the design of novel therapeutic strategies. The modulation of connexin expression may be an effective therapeutic approach in some types of cancers. Therefore, one important challenge is the search for mechanisms and new drugs, selectively modulating the expression of various connexin isoforms. We performed a systematic literature search up to February 2020 in the electronic databases PubMed and EMBASE. Our search terms were as follows: connexins, hemichannels, cancer and cancer treatment. This review aims to provide information about the role of connexins and gap junctions in cancer, as well as to discuss possible therapeutic options that are currently being studied.
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Boucher J, Balandre AC, Debant M, Vix J, Harnois T, Bourmeyster N, Péraudeau E, Chépied A, Clarhaut J, Debiais F, Monvoisin A, Cronier L. Cx43 Present at the Leading Edge Membrane Governs Promigratory Effects of Osteoblast-Conditioned Medium on Human Prostate Cancer Cells in the Context of Bone Metastasis. Cancers (Basel) 2020; 12:cancers12103013. [PMID: 33081404 PMCID: PMC7602984 DOI: 10.3390/cancers12103013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 12/12/2022] Open
Abstract
Simple Summary In its late stages, prostate cancer (PCa) is characterized by a high propensity to form osteoblastic bone metastases, mainly treated by palliative approaches. In a previous work, we demonstrated that a gap junctional protein, connexin43 (Cx43) is implicated both in the increase of aggressiveness of PCa cells and in their impact on bone. To analyze the reciprocal part of the dialogue, the current study addresses the role of Cx43 in the impact of bone microenvironment on PCa cells abilities. Using Cx43-overexpressing PCa cell lines, we determined that Cx43 is necessary for promigratory effect induced by osteoblastic conditioned media (ObCM) on individual cells. Next, we demonstrated the requirement of Cx43 membrane localization at the leading edge and the involvement of the cytoplasmic part in this ObCM-induced migration. Overall, our findings precise the role of Cx43 during PCa progression and its putative use as aggressiveness marker and as potential therapeutic targets. Abstract Among the different interacting molecules implicated in bone metastases, connexin43 (Cx43) may increase sensitivity of prostate cancer (PCa) cells to bone microenvironment, as suggested by our in silico and human tissue samples analyses that revealed increased level of Cx43 expression with PCa progression and a Cx43 specific expression in bone secondary sites. The goal of the present study was to understand how Cx43 influences PCa cells sensitivity and aggressiveness to bone microenvironment. By means of Cx43-overexpressing PCa cell lines, we revealed a Cx43-dependent promigratory effect of osteoblastic conditioned media (ObCM). This effect on directional migration relied on the presence of Cx43 at the plasma membrane and not on gap junctional intercellular communication and hemichannel functions. ObCM stimulation induced Rac1 activation and Cx43 interaction with cortactin in protrusions of migrating PCa cells. Finally, by transfecting two different truncated forms of Cx43 in LNCaP cells, we determined that the carboxy terminal (CT) part of Cx43 is crucial for the responsiveness of PCa cells to ObCM. Our study demonstrates that Cx43 level and its membrane localization modulate the phenotypic response of PCa cells to osteoblastic microenvironment and that its CT domain plays a pivotal role.
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Affiliation(s)
- Jonathan Boucher
- CNRS ERL7003, Laboratory Signalisation et Transports Ioniques Membranaires (STIM), University of Poitiers, 1 rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France; (J.B.); (A.-C.B.); (M.D.); (J.V.); (T.H.); (N.B.); (F.D.); (A.M.)
| | - Annie-Claire Balandre
- CNRS ERL7003, Laboratory Signalisation et Transports Ioniques Membranaires (STIM), University of Poitiers, 1 rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France; (J.B.); (A.-C.B.); (M.D.); (J.V.); (T.H.); (N.B.); (F.D.); (A.M.)
| | - Marjolaine Debant
- CNRS ERL7003, Laboratory Signalisation et Transports Ioniques Membranaires (STIM), University of Poitiers, 1 rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France; (J.B.); (A.-C.B.); (M.D.); (J.V.); (T.H.); (N.B.); (F.D.); (A.M.)
| | - Justine Vix
- CNRS ERL7003, Laboratory Signalisation et Transports Ioniques Membranaires (STIM), University of Poitiers, 1 rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France; (J.B.); (A.-C.B.); (M.D.); (J.V.); (T.H.); (N.B.); (F.D.); (A.M.)
- Department of Rheumatology, University Hospital Center of Poitiers, 2 Rue de la Milétrie, 86021 Poitiers, France
| | - Thomas Harnois
- CNRS ERL7003, Laboratory Signalisation et Transports Ioniques Membranaires (STIM), University of Poitiers, 1 rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France; (J.B.); (A.-C.B.); (M.D.); (J.V.); (T.H.); (N.B.); (F.D.); (A.M.)
| | - Nicolas Bourmeyster
- CNRS ERL7003, Laboratory Signalisation et Transports Ioniques Membranaires (STIM), University of Poitiers, 1 rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France; (J.B.); (A.-C.B.); (M.D.); (J.V.); (T.H.); (N.B.); (F.D.); (A.M.)
| | - Elodie Péraudeau
- University Hospital Center of Poitiers, 2 rue de la Milétrie, 86021 Poitiers, France; (E.P.); (J.C.)
- CNRS UMR 7285, Institut de Chimie des Milieux et des Matériaux de Poitiers (IC2MP), University of Poitiers, 4 Rue Michel Brunet, TSA 51106, CEDEX 09, 86073 Poitiers, France
| | - Amandine Chépied
- Laboratory of Experimental and Clinical Neurosciences, LNEC-INSERM U1084, UBM-Laboratoire de Cancérologie Biologique, CHU de Poitiers, 2 Rue de la Milétrie, 86000 Poitiers, France;
| | - Jonathan Clarhaut
- University Hospital Center of Poitiers, 2 rue de la Milétrie, 86021 Poitiers, France; (E.P.); (J.C.)
- CNRS UMR 7285, Institut de Chimie des Milieux et des Matériaux de Poitiers (IC2MP), University of Poitiers, 4 Rue Michel Brunet, TSA 51106, CEDEX 09, 86073 Poitiers, France
| | - Françoise Debiais
- CNRS ERL7003, Laboratory Signalisation et Transports Ioniques Membranaires (STIM), University of Poitiers, 1 rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France; (J.B.); (A.-C.B.); (M.D.); (J.V.); (T.H.); (N.B.); (F.D.); (A.M.)
- Department of Rheumatology, University Hospital Center of Poitiers, 2 Rue de la Milétrie, 86021 Poitiers, France
| | - Arnaud Monvoisin
- CNRS ERL7003, Laboratory Signalisation et Transports Ioniques Membranaires (STIM), University of Poitiers, 1 rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France; (J.B.); (A.-C.B.); (M.D.); (J.V.); (T.H.); (N.B.); (F.D.); (A.M.)
| | - Laurent Cronier
- CNRS ERL7003, Laboratory Signalisation et Transports Ioniques Membranaires (STIM), University of Poitiers, 1 rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France; (J.B.); (A.-C.B.); (M.D.); (J.V.); (T.H.); (N.B.); (F.D.); (A.M.)
- Correspondence: ; Tel.: +33-5-49-45-37-52
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Tishchenko A, Azorín DD, Vidal-Brime L, Muñoz MJ, Arenas PJ, Pearce C, Girao H, Ramón y Cajal S, Aasen T. Cx43 and Associated Cell Signaling Pathways Regulate Tunneling Nanotubes in Breast Cancer Cells. Cancers (Basel) 2020; 12:E2798. [PMID: 33003486 PMCID: PMC7601615 DOI: 10.3390/cancers12102798] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 09/25/2020] [Accepted: 09/25/2020] [Indexed: 12/12/2022] Open
Abstract
Connexin 43 (Cx43) forms gap junctions that mediate the direct intercellular diffusion of ions and small molecules between adjacent cells. Cx43 displays both pro- and anti-tumorigenic properties, but the mechanisms underlying these characteristics are not fully understood. Tunneling nanotubes (TNTs) are long and thin membrane projections that connect cells, facilitating the exchange of not only small molecules, but also larger proteins, organelles, bacteria, and viruses. Typically, TNTs exhibit increased formation under conditions of cellular stress and are more prominent in cancer cells, where they are generally thought to be pro-metastatic and to provide growth and survival advantages. Cx43 has been described in TNTs, where it is thought to regulate small molecule diffusion through gap junctions. Here, we developed a high-fidelity CRISPR/Cas9 system to knockout (KO) Cx43. We found that the loss of Cx43 expression was associated with significantly reduced TNT length and number in breast cancer cell lines. Notably, secreted factors present in conditioned medium stimulated TNTs more potently when derived from Cx43-expressing cells than from KO cells. Moreover, TNT formation was significantly induced by the inhibition of several key cancer signaling pathways that both regulate Cx43 and are regulated by Cx43, including RhoA kinase (ROCK), protein kinase A (PKA), focal adhesion kinase (FAK), and p38. Intriguingly, the drug-induced stimulation of TNTs was more potent in Cx43 KO cells than in wild-type (WT) cells. In conclusion, this work describes a novel non-canonical role for Cx43 in regulating TNTs, identifies key cancer signaling pathways that regulate TNTs in this setting, and provides mechanistic insight into a pro-tumorigenic role of Cx43 in cancer.
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Affiliation(s)
- Alexander Tishchenko
- Patologia Molecular Translacional, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (A.T.); (D.D.A.); (L.V.-B.); (M.J.M.); (P.J.A.); (C.P.); (S.R.yC.)
| | - Daniel D. Azorín
- Patologia Molecular Translacional, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (A.T.); (D.D.A.); (L.V.-B.); (M.J.M.); (P.J.A.); (C.P.); (S.R.yC.)
| | - Laia Vidal-Brime
- Patologia Molecular Translacional, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (A.T.); (D.D.A.); (L.V.-B.); (M.J.M.); (P.J.A.); (C.P.); (S.R.yC.)
| | - María José Muñoz
- Patologia Molecular Translacional, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (A.T.); (D.D.A.); (L.V.-B.); (M.J.M.); (P.J.A.); (C.P.); (S.R.yC.)
| | - Pol Jiménez Arenas
- Patologia Molecular Translacional, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (A.T.); (D.D.A.); (L.V.-B.); (M.J.M.); (P.J.A.); (C.P.); (S.R.yC.)
| | - Christopher Pearce
- Patologia Molecular Translacional, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (A.T.); (D.D.A.); (L.V.-B.); (M.J.M.); (P.J.A.); (C.P.); (S.R.yC.)
| | - Henrique Girao
- Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548 Coimbra, Portugal;
- Center for Innovative Biomedicine and Biotechnology, University of Coimbra, 3000-548 Coimbra, Portugal
- Clinical Academic Centre of Coimbra, CACC, 3000-548 Coimbra, Portugal
| | - Santiago Ramón y Cajal
- Patologia Molecular Translacional, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (A.T.); (D.D.A.); (L.V.-B.); (M.J.M.); (P.J.A.); (C.P.); (S.R.yC.)
- Anatomía Patológica, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
- CIBER de Cáncer (CIBERONC), Instituto de Salud Carlos III, Avenida de Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Trond Aasen
- Patologia Molecular Translacional, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (A.T.); (D.D.A.); (L.V.-B.); (M.J.M.); (P.J.A.); (C.P.); (S.R.yC.)
- CIBER de Cáncer (CIBERONC), Instituto de Salud Carlos III, Avenida de Monforte de Lemos 3-5, 28029 Madrid, Spain
- Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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Abstract
Term labour is a state of physiological inflammation orchestrated by multiple uterine tissues (both fetal and maternal). This physiological inflammation preceding and accompanying labour onset is characterized by an increase in cytokine and chemokine secretion by the fetal membranes, as well as uterine tissues (i.e., decidua and myometrium). Pro-inflammatory cytokines and chemokines activate circulating maternal peripheral leukocytes as well as the uterine vascular endothelium to permit leukocyte infiltration into the uterus. This inflammatory milieu, in the absence of infection, is required for the initiation of labour as the uterine-infiltrated leukocytes secrete matrix metalloproteinases to induce fetal membrane rupture and cervical ripening as well as various labour mediators, which promote contractions of the myometrium. Myometrial activation at term and the onset of labour contractions are directly related to the changes in the ovarian/placental hormone progesterone and its downstream mediators (i.e., the progesterone receptors, PRA/B), which are also critical for maintenance of pregnancy. Our recent data provides direct evidence in support of local and functional P4 withdrawal in the uterine muscle (myometrium) via the activator protein-1 (AP-1) mediated pathway. This review outlines known mechanisms regulating activation of human labour, including progesterone and cytokine signaling. Understanding of the molecular mechanism of myometrial activation and labour onset could facilitate the development of new therapeutics for high-risk pregnant women to prevent premature uterine activation and preterm birth.
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Affiliation(s)
- Oksana Shynlova
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada; Departments of Physiology and University of Toronto, Ontario, Canada; Obstetrics & Gynecology, University of Toronto, Ontario, Canada.
| | - Lubna Nadeem
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Jianhong Zhang
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Caroline Dunk
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Stephen Lye
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada; Departments of Physiology and University of Toronto, Ontario, Canada; Obstetrics & Gynecology, University of Toronto, Ontario, Canada
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Yawer A, Sychrová E, Labohá P, Raška J, Jambor T, Babica P, Sovadinová I. Endocrine-disrupting chemicals rapidly affect intercellular signaling in Leydig cells. Toxicol Appl Pharmacol 2020; 404:115177. [PMID: 32739526 DOI: 10.1016/j.taap.2020.115177] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/19/2020] [Accepted: 07/28/2020] [Indexed: 01/25/2023]
Abstract
A decline in male fertility possibly caused by environmental contaminants, namely endocrine-disrupting chemicals (EDCs), is a topic of public concern and scientific interest. This study addresses a specific role of testicular gap junctional intercellular communication (GJIC) between adjacent prepubertal Leydig cells in endocrine disruption and male reproductive toxicity. Organochlorine pesticides (lindane, methoxychlor, DDT), industrial chemicals (PCB153, bisphenol A, nonylphenol and octylphenol) as well as personal care product components (triclosan, triclocarban) rapidly dysregulated GJIC in murine Leydig TM3 cells. The selected GJIC-inhibiting EDCs (methoxychlor, triclosan, triclocarban, lindane, DDT) caused the immediate GJIC disruption by the relocation of gap junctional protein connexin 43 (Cx43) from the plasma membrane and the alternation of Cx43 phosphorylation pattern (Ser368, Ser279, Ser282) of its full-length and two N-truncated isoforms. After more prolonged exposure (24 h), EDCs decreased steady-state levels of full-length Cx43 protein and its two N-truncated isoforms, and eventually (triclosan, triclocarban) also tight junction protein Tjp-1. The disturbance of GJIC was accompanied by altered activity of mitogen-activated protein kinases MAPK-Erk1/2 and MAPK-p38, and a decrease in stimulated progesterone production. Our results indicate that EDCs might disrupt testicular homeostasis and development via disruption of testicular GJIC, a dysregulation of junctional and non-junctional functions of Cx43, activation of MAPKs, and disruption of an early stage of steroidogenesis in prepubertal Leydig cells. These critical disturbances of Leydig cell development and functions during a prepubertal period might be contributing to impaired male reproduction health later on.
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Affiliation(s)
- Affiefa Yawer
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, building A29, 625 00 Brno, Czech Republic
| | - Eliška Sychrová
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, building A29, 625 00 Brno, Czech Republic
| | - Petra Labohá
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, building A29, 625 00 Brno, Czech Republic
| | - Jan Raška
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, building A29, 625 00 Brno, Czech Republic
| | - Tomáš Jambor
- BioFood Centre, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovac Republic
| | - Pavel Babica
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, building A29, 625 00 Brno, Czech Republic
| | - Iva Sovadinová
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, building A29, 625 00 Brno, Czech Republic.
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50
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Dynamic UTR Usage Regulates Alternative Translation to Modulate Gap Junction Formation during Stress and Aging. Cell Rep 2020; 27:2737-2747.e5. [PMID: 31141695 PMCID: PMC6857847 DOI: 10.1016/j.celrep.2019.04.114] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 03/20/2019] [Accepted: 04/29/2019] [Indexed: 11/22/2022] Open
Abstract
Connexin43 (Cx43; gene name GJA1) is the most ubiquitously expressed gap junction protein, and understanding of its regulation largely falls under transcription and post-translational modification. In addition to Cx43, Gja1 mRNA encodes internally translated isoforms regulating gap junction formation, whose expression is modulated by TGF-β. Here, using RLM-RACE, we identify distinct Gja1 transcripts differing only in 5′ UTR length, of which two are upregulated during TGF-β exposure and hypoxia. Introduction of these transcripts into Gja1−/− cells phenocopies the response of Gja1 to TGF-β with reduced internal translation initiation. Inhibiting pathways downstream of TGF-β selectively regulates levels of Gja1 transcript isoforms and translation products. Reporter assays reveal enhanced translation of full-length Cx43 from shorter Gja1 5′ UTR isoforms. We also observe a correlation among UTR selection, translation, and reduced gap junction formation in aged heart tissue. These data elucidate a relationship between transcript isoform expression and translation initiation regulating intercellular communication. Connexin43 gap junctions enable direct intercellular communication facilitating action potential propagation. Internal translation of connexin43 mRNA generates the truncated isoform GJA1–20k, which promotes gap junction formation. During aging, Zeitz et al. find that activation of stress-response pathways shortens connexin43 mRNA UTRs to limit GJA1–20k translation coincident with gap junction loss.
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