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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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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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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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León-Fuentes IM, Salgado-Gil MG, Novoa MS, Retamal MA. Connexins in Cancer, the Possible Role of Connexin46 as a Cancer Stem Cell-Determining Protein. Biomolecules 2023; 13:1460. [PMID: 37892142 PMCID: PMC10604234 DOI: 10.3390/biom13101460] [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: 08/17/2023] [Revised: 09/15/2023] [Accepted: 09/22/2023] [Indexed: 10/29/2023] Open
Abstract
Cancer is a widespread and incurable disease caused by genetic mutations, leading to uncontrolled cell proliferation and metastasis. Connexins (Cx) are transmembrane proteins that facilitate intercellular communication via hemichannels and gap junction channels. Among them, Cx46 is found mostly in the eye lens. However, in pathological conditions, Cx46 has been observed in various types of cancers, such as glioblastoma, melanoma, and breast cancer. It has been demonstrated that elevated Cx46 levels in breast cancer contribute to cellular resistance to hypoxia, and it is an enhancer of cancer aggressiveness supporting a pro-tumoral role. Accordingly, Cx46 is associated with an increase in cancer stem cell phenotype. These cells display radio- and chemoresistance, high proliferative abilities, self-renewal, and differentiation capacities. This review aims to consolidate the knowledge of the relationship between Cx46, its role in forming hemichannels and gap junctions, and its connection with cancer and cancer stem cells.
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Affiliation(s)
| | | | | | - Mauricio A. Retamal
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, República de Honduras 12740, Las Condes, Santiago 7610496, Chile; (I.M.L.-F.); (M.G.S.-G.); (M.S.N.)
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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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Scott H, Dong L, Stevenson A, MacDonald AI, Srinivasan S, Massimi P, Banks L, Martin PE, Johnstone SR, Graham SV. The human discs large protein 1 interacts with and maintains connexin 43 at the plasma membrane in keratinocytes. J Cell Sci 2023; 136:jcs259984. [PMID: 37288673 PMCID: PMC10309592 DOI: 10.1242/jcs.259984] [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: 03/08/2022] [Accepted: 04/21/2023] [Indexed: 05/10/2023] Open
Abstract
Gap junction channels, composed of connexins, allow direct cell-to-cell communication. Connexin 43 (Cx43; also known as GJA1) is widely expressed in tissues, including the epidermis. In a previous study of human papillomavirus-positive cervical epithelial tumour cells, we identified Cx43 as a binding partner of the human homologue of Drosophila Discs large (Dlg1; also known as SAP97). Dlg1 is a member of the membrane associated-guanylate kinase (MAGUK) scaffolding protein family, which is known to control cell shape and polarity. Here, we show that Cx43 also interacts with Dlg1 in uninfected keratinocytes in vitro and in keratinocytes, dermal cells and adipocytes in normal human epidermis in vivo. Depletion of Dlg1 in keratinocytes did not alter Cx43 transcription but was associated with a reduction in Cx43 protein levels. Reduced Dlg1 levels in keratinocytes resulted in a reduction in Cx43 at the plasma membrane with a concomitant reduction in gap junctional intercellular communication and relocation of Cx43 to the Golgi compartment. Our data suggest a key role for Dlg1 in maintaining Cx43 at the plasma membrane in keratinocytes.
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Affiliation(s)
- Harry Scott
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Li Dong
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Andrew Stevenson
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Alasdair I. MacDonald
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Sharmila Srinivasan
- Translation Research Platform for Veterinary Biologicals, Chennai, Tamil Nadu, India
| | - Paola Massimi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Lawrence Banks
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Patricia E. Martin
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK
| | - Scott R. Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke VA 24016, USA
| | - Sheila V. Graham
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
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Zeitz MJ, Smyth JW. Gap Junctions and Ageing. Subcell Biochem 2023; 102:113-137. [PMID: 36600132 DOI: 10.1007/978-3-031-21410-3_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Gap junctions, comprising connexin proteins, create conduits directly coupling the cytoplasms of adjacent cells. Expressed in essentially all tissues, dynamic gap junction structures enable the exchange of small molecules including ions and second messengers, and are central to maintenance of homeostasis and synchronized excitability. With such diverse and critical roles throughout the body, it is unsurprising that alterations to gap junction and/or connexin expression and function underlie a broad array of age-related pathologies. From neurological dysfunction to cardiac arrhythmia and bone loss, it is hard to identify a human disease state that does not involve reduced, or in some cases inappropriate, intercellular communication to affect organ function. With a complex life cycle encompassing several key regulatory steps, pathological gap junction remodeling during ageing can arise from alterations in gene expression, translation, intracellular trafficking, and posttranslational modification of connexins. Connexin proteins are now known to "moonlight" and perform a variety of non-junctional functions in the cell, independent of gap junctions. Furthermore, connexin "hemichannels" on the cell surface can communicate with the extracellular space without ever coupling to an adjacent cell to form a gap junction channel. This chapter will focus primarily on gap junctions in ageing, but such non-junctional connexin functions will be referred to where appropriate and the full spectrum of connexin biology should be noted as potentially causative/contributing to some findings in connexin knockout animals, for example.
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Affiliation(s)
- Michael J Zeitz
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA.,FBRI Center for Vascular and Heart Research, Roanoke, VA, USA
| | - James W Smyth
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA. .,FBRI Center for Vascular and Heart Research, Roanoke, VA, USA. .,Department of Biological Sciences, College of Science, Virginia Tech, Blacksburg, VA, USA. .,Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA.
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Mydin RBSMN, Mahboob A, Sreekantan S, Saharudin KA, Qazem EQ, Hazan R, Wajidi MFF. Mechano-cytoskeleton remodeling mechanism and molecular docking studies on nanosurface technology: Titania nanotube arrays. Biotechnol Appl Biochem 2022. [PMID: 36567620 DOI: 10.1002/bab.2421] [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: 03/13/2022] [Accepted: 06/26/2022] [Indexed: 12/27/2022]
Abstract
In biomedical implant technology, nanosurface such as titania nanotube arrays (TNA) could provide better cellular adaptation, especially for long-term tissue acceptance response. Mechanotransduction activities of TNA nanosurface could involve the cytoskeleton remodeling mechanism. However, there is no clear insight into TNA mechano-cytoskeleton remodeling activities, especially computational approaches. Epithelial cells have played critical interface between biomedical implant surface and tissue acceptance, particularly for long-term interaction. Therefore, this study investigates genomic responses that are responsible for cell-TNA mechano-stimulus using epithelial cells model. Findings suggested that cell-TNA interaction may improve structural and extracellular matrix (ECM) support on the cells as an adaptive response toward the nanosurface topography. More specifically, the surface topography of the TNA might improve the cell polarity and adhesion properties via the interaction of the plasma membrane and intracellular matrix responses. TNA nanosurface might engross the cytoskeleton remodeling activities for multidirectional cell movement and cellular protrusions on TNA nanosurface. These observations are supported by the molecular docking profiles that determine proteins' in silico binding mechanism on TNA. This active cell-surface revamping would allow cells to adapt to develop a protective barrier toward TNA nanosurface, thus enhancing biocompatibility properties distinctly for long-term interaction. The findings from this study will be beneficial toward nano-molecular knowledge of designing functional nanosurface technology for advanced medical implant applications.
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Affiliation(s)
- Rabiatul Basria S M N Mydin
- Department of Biomedical Science, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Pulau Pinang, Malaysia
| | - Alam Mahboob
- Division of Chemistry & Biotechnology, Dongguk University, Gyeongju, Republic of Korea
| | - Srimala Sreekantan
- School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Pulau Pinang, Malaysia
| | - Khairul Arifah Saharudin
- School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Pulau Pinang, Malaysia.,Qdos Interconnect Sdn Bhd, Pulau Pinang, Malaysia
| | - Ekhlas Qaid Qazem
- Materials Technology Group, Industrial Technology Division, Nuclear Malaysia Agency, Kajang, Selangor, Malaysia
| | - Roshasnorlyza Hazan
- Department of Medical Laboratory, College of Medicine and Health Sciences, Hodeidah University, Hodeidah, Yemen
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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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Duch P, Díaz-Valdivia N, Ikemori R, Gabasa M, Radisky ES, Arshakyan M, Gea-Sorlí S, Mateu-Bosch A, Bragado P, Carrasco JL, Mori H, Ramírez J, Teixidó C, Reguart N, Fillat C, Radisky DC, Alcaraz J. Aberrant TIMP-1 overexpression in tumor-associated fibroblasts drives tumor progression through CD63 in lung adenocarcinoma. Matrix Biol 2022; 111:207-225. [PMID: 35787446 PMCID: PMC9667815 DOI: 10.1016/j.matbio.2022.06.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 06/10/2022] [Accepted: 06/29/2022] [Indexed: 12/29/2022]
Abstract
Tissue inhibitor of metalloproteinase-1 (TIMP-1) is an important regulator of extracellular matrix turnover that has been traditionally regarded as a potential tumor suppressor owing to its inhibitory effects of matrix metalloproteinases. Intriguingly, this interpretation has been challenged by the consistent observation that increased expression of TIMP-1 is associated with poor prognosis in virtually all cancer types including lung cancer, supporting a tumor-promoting function. However, how TIMP-1 is dysregulated within the tumor microenvironment and how it drives tumor progression in lung cancer is poorly understood. We analyzed the expression of TIMP-1 and its cell surface receptor CD63 in two major lung cancer subtypes: lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC), and defined the tumor-promoting effects of their interaction. We found that TIMP-1 is aberrantly overexpressed in tumor-associated fibroblasts (TAFs) in ADC compared to SCC. Mechanistically, TIMP-1 overexpression was mediated by the selective hyperactivity of the pro-fibrotic TGF-β1/SMAD3 pathway in ADC-TAFs. Likewise, CD63 was upregulated in ADC compared to SCC cells. Genetic analyses revealed that TIMP-1 secreted by TGF-β1-activated ADC-TAFs is both necessary and sufficient to enhance growth and invasion of ADC cancer cells in culture, and that tumor cell expression of CD63 was required for these effects. Consistently, in vivo analyses revealed that ADC cells co-injected with fibroblasts with reduced SMAD3 or TIMP-1 expression into immunocompromised mice attenuated tumor aggressiveness compared to tumors bearing parental fibroblasts. We also found that high TIMP1 and CD63 mRNA levels combined define a stronger prognostic biomarker than TIMP1 alone. Our results identify an excessive stromal TIMP-1 within the tumor microenvironment selectively in lung ADC, and implicate it in a novel tumor-promoting TAF-carcinoma crosstalk, thereby pointing to TIMP-1/CD63 interaction as a novel therapeutic target in lung cancer.
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Affiliation(s)
- Paula Duch
- Unit of Biophysics and Bioengineering, Department of Biomedicine, School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona 08036, Spain
| | - Natalia Díaz-Valdivia
- Unit of Biophysics and Bioengineering, Department of Biomedicine, School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona 08036, Spain
| | - Rafael Ikemori
- Unit of Biophysics and Bioengineering, Department of Biomedicine, School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona 08036, Spain
| | - Marta Gabasa
- Unit of Biophysics and Bioengineering, Department of Biomedicine, School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona 08036, Spain; Thoracic Oncology Unit, Hospital Clinic Barcelona, Barcelona 08036, Spain
| | - Evette S Radisky
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL 32224, United States
| | - Marselina Arshakyan
- Unit of Biophysics and Bioengineering, Department of Biomedicine, School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona 08036, Spain
| | - Sabrina Gea-Sorlí
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid 08029, Spain
| | - Anna Mateu-Bosch
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid 08029, Spain
| | - Paloma Bragado
- Instituto de Investigaciones Sanitarias San Carlos (IdISSC), Madrid, 28040, Spain; Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain
| | - Josep Lluís Carrasco
- Unit of Biostatistics, Department of Basic Clinical Practice, School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Hidetoshi Mori
- Center for Immunology and Infectious Diseases, University of California Davis, Davis, CA 95616, United States
| | - Josep Ramírez
- Thoracic Oncology Unit, Hospital Clinic Barcelona, Barcelona 08036, Spain; Pathology Service, Hospital Clínic de Barcelona, Barcelona 08036, Spain; Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Cristina Teixidó
- Thoracic Oncology Unit, Hospital Clinic Barcelona, Barcelona 08036, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain; Pathology Service, Hospital Clínic de Barcelona, Barcelona 08036, Spain
| | - Noemí Reguart
- Thoracic Oncology Unit, Hospital Clinic Barcelona, Barcelona 08036, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain
| | - Cristina Fillat
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid 08029, Spain; Department of Medicine, School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Derek C Radisky
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL 32224, United States
| | - Jordi Alcaraz
- Unit of Biophysics and Bioengineering, Department of Biomedicine, School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona 08036, Spain; Thoracic Oncology Unit, Hospital Clinic Barcelona, Barcelona 08036, Spain; Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain.
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11
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Gao Y, Wang C, Jin F, Han G, Cui C. Therapeutic effect of extracellular vesicles from different cell sources in traumatic brain injury. Tissue Cell 2022; 76:101772. [DOI: 10.1016/j.tice.2022.101772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/02/2022] [Accepted: 03/02/2022] [Indexed: 10/18/2022]
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12
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Yawer A, Sychrová E, Raška J, Babica P, Sovadinová I. Endocrine-disrupting chemicals affect sertoli TM4 cell functionality through dysregulation of gap junctional intercellular communication in vitro. Food Chem Toxicol 2022; 164:113004. [PMID: 35413382 DOI: 10.1016/j.fct.2022.113004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/20/2022] [Accepted: 04/06/2022] [Indexed: 01/10/2023]
Abstract
The frequencies of adverse outcomes associated with male reproductive health, including infertility and testicular cancer, are increasing. These adverse trends are partially attributed to increased exposure to environmental agents such as endocrine-disrupting chemicals (EDCs). This study addresses effects on EDCs on adjacent prepubertal Sertoli TM4 cells, specifically on 1) testicular gap junctional intercellular communication (GJIC), one of the hallmarks of non-genotoxic carcinogenicity, 2) GJIC building blocks connexins (Cx), and 3) mitogen-activated protein kinases MAPKs. We selected eight representatives of EDCs: bisphenol A and organochlorine chemicals such as pesticides dichlorodiphenyltrichloroethane, lindane, methoxychlor, and vinclozolin, industrial chemical 2,2',4,4',5,5'-hexachlorobiphenyl, and components of personal care products, triclocarban and triclosan. EDCs rapidly dysregulated GJIC in Sertoli TM4 cells mainly via MAPK p38 and/or Erk1/2/pathways by the intermediate hyper- or de-phosphorylation of Cx43 (Ser368, Ser282) and translocalization of Cx43 from the plasma membrane, suggesting disturbed intracellular trafficking of Cx43 protein. Surprisingly, EDCs did not rapidly activate MAPK Erk1/2 or p38; on the contrary, TCC and TCS decreased their activity (phosphorylation). Our results indicate that EDCs might disrupt testicular homeostasis and development via testicular GJIC, junctional and non-junctional functions of Cx43 and MAPK-signalling pathways in Sertoli cells.
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Affiliation(s)
- Affiefa Yawer
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Eliška Sychrová
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Jan Raška
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Pavel Babica
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Iva Sovadinová
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
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13
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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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14
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Gap Junction-Dependent and -Independent Functions of Connexin43 in Biology. BIOLOGY 2022; 11:biology11020283. [PMID: 35205149 PMCID: PMC8869330 DOI: 10.3390/biology11020283] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 12/21/2022]
Abstract
For the first time in animal evolution, the emergence of gap junctions allowed direct exchanges of cellular substances for communication between two cells. Innexin proteins constituted primordial gap junctions until the connexin protein emerged in deuterostomes and took over the gap junction function. After hundreds of millions of years of gene duplication, the connexin gene family now comprises 21 members in the human genome. Notably, GJA1, which encodes the Connexin43 protein, is one of the most widely expressed and commonly studied connexin genes. The loss of Gja1 in mice leads to swelling and a blockage of the right ventricular outflow tract and death of the embryos at birth, suggesting a vital role of Connexin43 gap junction in heart development. Since then, the importance of Connexin43-mediated gap junction function has been constantly expanded to other types of cells. Other than forming gap junctions, Connexin43 can also form hemichannels to release or uptake small molecules from the environment or even mediate many physiological processes in a gap junction-independent manner on plasma membranes. Surprisingly, Connexin43 also localizes to mitochondria in the cell, playing important roles in mitochondrial potassium import and respiration. At the molecular level, Connexin43 mRNA and protein are processed with very distinct mechanisms to yield carboxyl-terminal fragments with different sizes, which have their unique subcellular localization and distinct biological activities. Due to many exciting advancements in Connexin43 research, this review aims to start with a brief introduction of Connexin43 and then focuses on updating our knowledge of its gap junction-independent functions.
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15
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Cx43 Promotes Endothelial Cell Migration and Angiogenesis via the Tyrosine Phosphatase SHP-2. Int J Mol Sci 2021; 23:ijms23010294. [PMID: 35008716 PMCID: PMC8745637 DOI: 10.3390/ijms23010294] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/21/2021] [Accepted: 12/24/2021] [Indexed: 12/16/2022] Open
Abstract
The gap junction protein connexin 43 (Cx43) is associated with increased cell migration and to related changes of the actin cytoskeleton, which is mediated via its C-terminal cytoplasmic tail and is independent of its channel function. Cx43 has been shown to possess an angiogenic potential, however, the role of Cx43 in endothelial cell migration has not yet been investigated. Here, we found that the knock-down of Cx43 by siRNA in human microvascular endothelial cells (HMEC) reduces migration, as assessed by a wound assay in vitro and impaired aortic vessel sprouting ex vivo. Immunoprecipitation of Cx43 revealed an interaction with the tyrosine phosphatase SHP-2, which enhanced its phosphatase activity, as observed in Cx43 expressing HeLa cells compared to cells treated with an empty vector. Interestingly, the expression of a dominant negative substrate trapping mutant SHP-2 (CS) in HMEC, via lentiviral transduction, also impaired endothelial migration to a similar extent as Cx43 siRNA compared to SHP-2 WT. Moreover, the reduction in endothelial migration upon Cx43 siRNA could not be rescued by the introduction of a constitutively active SHP-2 construct (EA). Our data demonstrate that Cx43 and SHP-2 mediate endothelial cell migration, revealing a novel interaction between Cx43 and SHP-2, which is essential for this process.
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16
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Li B, Wei Y, Li Q, Chen N, Li J, Liu L, Zhang J, Wang Y, Sun Y, Shi J, Wang L, Shao Z, Hu J, Fan C. Nanomechanical Induction of Autophagy-Related Fluorescence in Single Cells with Atomic Force Microscopy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2102989. [PMID: 34708576 PMCID: PMC8693060 DOI: 10.1002/advs.202102989] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/10/2021] [Indexed: 05/25/2023]
Abstract
Mechanistic understanding of how living systems sense, transduce, and respond to mechanical cues has important implications in development, physiology, and therapy. Here, the authors use an integrated atomic force microscope (AFM) and brightfield/epifluorescent microscope platform to precisely simulate living single cells or groups of cells under physiological conditions, in real time, concomitantly measuring the single-cell autophagic response and its transmission to neighboring cells. Dual-color fluorescence monitoring of the cellular autophagic response reveals the dynamics of autophagosome formation, degradation, and induction in neighboring contacting and noncontacting cells. Autophagosome formation is dependent on both the applied force and contact area of the AFM tip. More importantly, the enhancement of the autophagic responses in neighboring cells via a gap junction-dependent mechanism is observed. This AFM-based nanoacupuncture platform can serve as a tool for elucidating the primary mechanism underlying mechanical stimulation of living systems and other biomechanical therapeutics.
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Affiliation(s)
- Bin Li
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
- Shanghai Synchrotron Radiation FacilityZhanjiang LaboratoryShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China
| | - Yuhui Wei
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
- Shanghai Synchrotron Radiation FacilityZhanjiang LaboratoryShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China
- University of Chinese Academy of SciencesBeijing100049China
| | - Qian Li
- School of Chemistry and Chemical EngineeringFrontiers Science Center for Transformative Molecules and National Center for Translational MedicineShanghai Jiao Tong UniversityShanghai200240China
| | - Nan Chen
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
| | - Jiang Li
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
- Shanghai Synchrotron Radiation FacilityZhanjiang LaboratoryShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China
| | - Lin Liu
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
| | - Jinjin Zhang
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
- Shanghai Synchrotron Radiation FacilityZhanjiang LaboratoryShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China
| | - Ying Wang
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
- Shanghai Synchrotron Radiation FacilityZhanjiang LaboratoryShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China
| | - Yanhong Sun
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
- Shanghai Synchrotron Radiation FacilityZhanjiang LaboratoryShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China
| | - Jiye Shi
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
| | - Lihua Wang
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
- Shanghai Synchrotron Radiation FacilityZhanjiang LaboratoryShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China
| | - Zhifeng Shao
- State Key Laboratory for Oncogenes and Bio‐ID CenterSchool of Biomedical EngineeringShanghai Jiao Tong UniversityShanghai200240China
| | - Jun Hu
- CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China
- Shanghai Synchrotron Radiation FacilityZhanjiang LaboratoryShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China
| | - Chunhai Fan
- School of Chemistry and Chemical EngineeringFrontiers Science Center for Transformative Molecules and National Center for Translational MedicineShanghai Jiao Tong UniversityShanghai200240China
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17
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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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18
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Orellana VP, Tittarelli A, Retamal MA. Connexins in melanoma: Potential role of Cx46 in its aggressiveness. Pigment Cell Melanoma Res 2021; 34:853-868. [PMID: 33140904 DOI: 10.1111/pcmr.12945] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/20/2020] [Accepted: 10/27/2020] [Indexed: 12/19/2022]
Abstract
Melanoma is the most aggressive skin cancer, and in metastatic advanced states, it is completely refractory to chemotherapy. Therefore, it is relevant to understand the molecular bases that rule their aggressiveness. Connexins (Cxs) are proteins that under normal physiological conditions participate in intercellular communication, via the exchange of signaling molecules between the cytoplasm and extracellular milieu and the exchange of ions/second messengers between the cytoplasm of contacting cells. These proteins have shown important roles in cancer progression, chemo- and radiotherapy resistance, and metastasis. Accordingly, Cx26 and Cx43 seem to play important roles in melanoma progression and metastasis. On the other hand, Cx46 is typically expressed in the eye lens, where it seems to be associated with oxidative stress protection in fiber lens cells. However, in the last decade, Cx46 expression has been associated with breast and brain cancers, due to its role in potentiation of both extracellular vesicle release and cancer stem cell-like properties. In this review, we analyzed a potential role of Cx46 as a new biomarker and therapeutic target in melanoma.
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Affiliation(s)
- Viviana P Orellana
- Universidad del Desarrollo. Centro de Fisiología Celular e Integrativa, Clinica Alemana Facultad de Medicina, Santiago, Chile
- Universidad del Desarrollo. Programa de Comunicación Celular en Cáncer, Clínica Alemana Facultad de Medicina, Santiago, Chile
| | - Andrés Tittarelli
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación (PIDi), Universidad Tecnológica Metropolitana (UTEM), Santiago, Chile
| | - Mauricio A Retamal
- Universidad del Desarrollo. Centro de Fisiología Celular e Integrativa, Clinica Alemana Facultad de Medicina, Santiago, Chile
- Universidad del Desarrollo. Programa de Comunicación Celular en Cáncer, Clínica Alemana Facultad de Medicina, Santiago, Chile
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19
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Grosz BR, Svaren J, Perez-Siles G, Nicholson GA, Kennerson ML. Revisiting the pathogenic mechanism of the GJB1 5' UTR c.-103C > T mutation causing CMTX1. Neurogenetics 2021; 22:149-160. [PMID: 34089394 PMCID: PMC8241655 DOI: 10.1007/s10048-021-00650-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/25/2021] [Indexed: 11/25/2022]
Abstract
The second most common form of Charcot-Marie-Tooth neuropathy (CMT), X-linked CMT type X1 (CMTX1), is caused by coding and non-coding mutations in the gap junction beta 1 (GJB1) gene. The non-coding GJB1 c.-103C > T mutation (NM_000166.5) has been reported to cause CMTX1 in multiple families. This study assessed the internal ribosomal entry site (IRES) activity previously reported for the rat Gjb1 P2 5' untranslated region (UTR). Using a bicistronic assay and transfecting RT4 Schwann cells, IRES activity of the human GJB1 P2 5' UTR was compared to the GJB1 P2 5' UTR containing either the c.-103C > T mutation or the non-pathogenic c.-102G > A variant. No differences in GJB1 P2 5' UTR IRES activity were observed between the negative control, the wild-type P2 5' UTR, the c.-103C > T 5' UTR or the c.-102G > A 5' UTR, irrespective of the GJB1 intron being present (p = .429 with intron, and p = .865 without). A theoretical c.-131A > G variant was predicted to result in the same RNA secondary structure as the GJB1 c.-103C > T P2 5' UTR. However, no significant difference was observed between expression from the wild-type GJB1 P2 5' UTR and the GJB1 c.-131A > G variant (p = .688). Deletion of the conserved region surrounding the c.-103C > T mutation (c.-108_-103del) resulted in significantly higher expression than the c.-103C > T mutation alone (p = .019), suggesting that the conserved c.-108_-103 region was not essential for translation. The reporter assays in this study do not recapitulate the previously reported GJB1 IRES activity and suggest an alternate pathogenic mechanism for the c.-103C > T CMTX1 non-coding mutation.
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Affiliation(s)
- Bianca R Grosz
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Concord, NSW, Australia.
- Sydney Medical School, University of Sydney, Camperdown, NSW, Australia.
| | - John Svaren
- Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Gonzalo Perez-Siles
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Concord, NSW, Australia
- Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
| | - Garth A Nicholson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Concord, NSW, Australia
- Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
- Molecular Medicine Laboratory, Concord Repatriation General Hospital, Concord, NSW, Australia
| | - Marina L Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Concord, NSW, Australia
- Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
- Molecular Medicine Laboratory, Concord Repatriation General Hospital, Concord, NSW, Australia
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20
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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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21
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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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22
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Homme RP, Sandhu HS, George AK, Tyagi SC, Singh M. Sustained Inhibition of NF-κB Activity Mitigates Retinal Vasculopathy in Diabetes. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:947-964. [PMID: 33640319 DOI: 10.1016/j.ajpath.2021.01.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 01/13/2021] [Accepted: 01/20/2021] [Indexed: 12/12/2022]
Abstract
This study investigated the effects of long-term NF-κB inhibition in mitigating retinal vasculopathy in a type 1 diabetic mouse model (Akita, Ins2Akita). Akita and wild-type (C57BL/6J) male mice, 24 to 26 weeks old, were treated with or without a selective inhibitor of NF-κB, 4-methyl-N1-(3-phenyl-propyl) benzene-1,2-diamine (JSH-23), for 4 weeks. Treatment was given when the mice were at least 24 weeks old. Metabolic parameters, key inflammatory mediators, blood-retinal barrier junction molecules, retinal structure, and function were measured. JSH-23 significantly lowered basal glucose levels and intraocular pressure in Akita. It also mitigated vascular remodeling and microaneurysms significantly. Optical coherence tomography of untreated Akita showed thinning of retinal layers; however, treatment with JSH-23 could prevent it. Electroretinogram demonstrated that A- and B-waves in Akita were significantly smaller than in wild type mice, indicating that JSH-23 intervention prevented loss of retinal function. Protein levels and gene expression of key inflammatory mediators, such as NOD-like receptor family pyrin domain-containing 3, intercellular adhesion molecule-1, inducible nitric oxide synthase, and cyclooxygenase-2, were decreased after JSH-23 treatment. At the same time, connexin-43 and occludin were maintained. Vision-guided behavior also improved significantly. The results show that reducing inflammation could protect the diabetic retina and its vasculature. Findings appear to have broader implications in treating not only ocular conditions but also other vasculopathies.
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Affiliation(s)
- Rubens P Homme
- Eye and Vision Science Laboratory, University of Louisville School of Medicine, Louisville, Kentucky; Department of Physiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Harpal S Sandhu
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, Kentucky; Kentucky Lions Eye Center, University of Louisville School of Medicine, Louisville, Kentucky
| | - Akash K George
- Eye and Vision Science Laboratory, University of Louisville School of Medicine, Louisville, Kentucky; Department of Physiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Suresh C Tyagi
- Department of Physiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Mahavir Singh
- Eye and Vision Science Laboratory, University of Louisville School of Medicine, Louisville, Kentucky; Department of Physiology, University of Louisville School of Medicine, Louisville, Kentucky.
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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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24
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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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25
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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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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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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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Abstract
Of the 21 members of the connexin family, 4 (Cx37, Cx40, Cx43, and Cx45) are expressed in the endothelium and/or smooth muscle of intact blood vessels to a variable and dynamically regulated degree. Full-length connexins oligomerize and form channel structures connecting the cytosol of adjacent cells (gap junctions) or the cytosol with the extracellular space (hemichannels). The different connexins vary mainly with regard to length and sequence of their cytosolic COOH-terminal tails. These COOH-terminal parts, which in the case of Cx43 are also translated as independent short isoforms, are involved in various cellular signaling cascades and regulate cell functions. This review focuses on channel-dependent and -independent effects of connexins in vascular cells. Channels play an essential role in coordinating and synchronizing endothelial and smooth muscle activity and in their interplay, in the control of vasomotor actions of blood vessels including endothelial cell reactivity to agonist stimulation, nitric oxide-dependent dilation, and endothelial-derived hyperpolarizing factor-type responses. Further channel-dependent and -independent roles of connexins in blood vessel function range from basic processes of vascular remodeling and angiogenesis to vascular permeability and interactions with leukocytes with the vessel wall. Together, these connexin functions constitute an often underestimated basis for the enormous plasticity of vascular morphology and function enabling the required dynamic adaptation of the vascular system to varying tissue demands.
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Affiliation(s)
- Ulrich Pohl
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Planegg-Martinsried, Germany; Biomedical Centre, Cardiovascular Physiology, LMU Munich, Planegg-Martinsried, Germany; German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Munich, Germany; and Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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30
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Hausenloy DJ, Schulz R, Girao H, Kwak BR, De Stefani D, Rizzuto R, Bernardi P, Di Lisa F. Mitochondrial ion channels as targets for cardioprotection. J Cell Mol Med 2020; 24:7102-7114. [PMID: 32490600 PMCID: PMC7339171 DOI: 10.1111/jcmm.15341] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/31/2020] [Accepted: 04/12/2020] [Indexed: 12/14/2022] Open
Abstract
Acute myocardial infarction (AMI) and the heart failure (HF) that often result remain the leading causes of death and disability worldwide. As such, new therapeutic targets need to be discovered to protect the myocardium against acute ischaemia/reperfusion (I/R) injury in order to reduce myocardial infarct (MI) size, preserve left ventricular function and prevent the onset of HF. Mitochondrial dysfunction during acute I/R injury is a critical determinant of cell death following AMI, and therefore, ion channels in the inner mitochondrial membrane, which are known to influence cell death and survival, provide potential therapeutic targets for cardioprotection. In this article, we review the role of mitochondrial ion channels, which are known to modulate susceptibility to acute myocardial I/R injury, and we explore their potential roles as therapeutic targets for reducing MI size and preventing HF following AMI.
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Affiliation(s)
- Derek J. Hausenloy
- Cardiovascular & Metabolic Disorders ProgramDuke‐National University of Singapore Medical SchoolSingaporeSingapore
- National Heart Research Institute SingaporeNational Heart CentreSingaporeSingapore
- Yong Loo Lin School of MedicineNational University SingaporeSingaporeSingapore
- The Hatter Cardiovascular InstituteUniversity College LondonLondonUK
- Cardiovascular Research CenterCollege of Medical and Health SciencesAsia UniversityTaichung CityTaiwan
| | - Rainer Schulz
- Institute of PhysiologyJustus‐Liebig University GiessenGiessenGermany
| | - Henrique Girao
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of MedicineUniversity of CoimbraCoimbraPortugal
- Center for Innovative Biomedicine and Biotechnology (CIBB)University of CoimbraCoimbraPortugal
- Clinical Academic Centre of CoimbraCACCCoimbraPortugal
| | - Brenda R. Kwak
- Department of Pathology and ImmunologyUniversity of GenevaGenevaSwitzerland
| | - Diego De Stefani
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
| | - Rosario Rizzuto
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
| | - Paolo Bernardi
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
- CNR Neuroscience InstitutePadovaItaly
| | - Fabio Di Lisa
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
- CNR Neuroscience InstitutePadovaItaly
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31
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Ren D, Zheng P, Feng J, Gong Y, Wang Y, Duan J, Zhao L, Deng J, Chen H, Zou S, Hong T, Chen W. Overexpression of Astrocytes-Specific GJA1-20k Enhances the Viability and Recovery of the Neurons in a Rat Model of Traumatic Brain Injury. ACS Chem Neurosci 2020; 11:1643-1650. [PMID: 32401478 DOI: 10.1021/acschemneuro.0c00142] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Traumatic brain injury (TBI) is a devastating actuality in clinics worldwide. It is estimated that approximately 10 million people among the world suffer from TBI each year, and a considerable number of patients will be temporarily or permanently disabled or even die due to this disease. Astrocytes play a very important role in the repair of brain tissue after TBI, including the formation of a neuroprotective barrier, inhibition of brain edema, and inhibition of normal nerve cell apoptosis. However, the detailed mechanism underlying this protective effect is still unclear. To investigate the regulatory factors of astrocytes to other neurons post-TBI, we established a TBI rat model and used the AAV to mediate the overexpression of GJA1-20k in astrocytes of rats. And functionally, the specific overexpression of GJA1-20k in astrocytes promoted the viability and recovery of neurons in TBI. Mechanistically, the astrocytes-specific upregulation of GJA1-20k protected the function of mitochondria in neurons of FPI rats, thus suppressing the apoptosis of the damaged neurons. We hereby reported that astrocytes-specific overexpression of GJA1-20k enhanced the viability and recovery of the neurons in TBI through regulating their mitochondrial function.
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Affiliation(s)
- Dabin Ren
- Department of Neurosurgery, the People’s Hospital of Shanghai Pudong New Area Affiliated to Shanghai University of Medicine and Health Sciences, Shanghai 201299, P. R. China
| | - Ping Zheng
- Department of Neurosurgery, the People’s Hospital of Shanghai Pudong New Area Affiliated to Shanghai University of Medicine and Health Sciences, Shanghai 201299, P. R. China
| | - Jiugeng Feng
- Department of Neurosurgery, the First Affiliated Hospital of Nanchang University, Nanchang 330008, Jiangxi, P. R. China
| | - Yuqin Gong
- Department of Operation Room, the Second Affiliated Hospital of Nanchang University, Nanchang 330009, Jiangxi, P. R. China
| | - Yang Wang
- Department of Neurosurgery, the First Affiliated Hospital of Nanchang University, Nanchang 330008, Jiangxi, P. R. China
| | - Jian Duan
- Department of Neurosurgery, the First Affiliated Hospital of Nanchang University, Nanchang 330008, Jiangxi, P. R. China
| | - Lin Zhao
- Department of Neurosurgery, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210009, Jiangsu China
| | - Jun Deng
- Department of Emergency@Trauma Center, the First Affiliated Hospital of Nanchang University, Nanchang 330008, Jiangxi, P. R. China
| | - Haiming Chen
- Department of Emergency@Trauma Center, the First Affiliated Hospital of Nanchang University, Nanchang 330008, Jiangxi, P. R. China
| | - Shufeng Zou
- Department of Neurosurgery, the First Affiliated Hospital of Nanchang University, Nanchang 330008, Jiangxi, P. R. China
| | - Tao Hong
- Department of Neurosurgery, the First Affiliated Hospital of Nanchang University, Nanchang 330008, Jiangxi, P. R. China
| | - Wei Chen
- Department of Neurosurgery, the People’s Hospital of Shanghai Pudong New Area Affiliated to Shanghai University of Medicine and Health Sciences, Shanghai 201299, P. R. China
- Department of Emergency@Trauma Center, the First Affiliated Hospital of Nanchang University, Nanchang 330008, Jiangxi, P. R. China
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Epifantseva I, Xiao S, Baum RE, Kléber AG, Hong T, Shaw RM. An Alternatively Translated Connexin 43 Isoform, GJA1-11k, Localizes to the Nucleus and Can Inhibit Cell Cycle Progression. Biomolecules 2020; 10:biom10030473. [PMID: 32244859 PMCID: PMC7175147 DOI: 10.3390/biom10030473] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/10/2020] [Accepted: 03/15/2020] [Indexed: 12/14/2022] Open
Abstract
Connexin 43 (Cx43) is a gap junction protein that assembles at the cell border to form intercellular gap junction (GJ) channels which allow for cell-cell communication by facilitating the rapid transmission of ions and other small molecules between adjacent cells. Non-canonical roles of Cx43, and specifically its C-terminal domain, have been identified in the regulation of Cx43 trafficking, mitochondrial preconditioning, cell proliferation, and tumor formation, yet the mechanisms are still being explored. It was recently identified that up to six truncated isoforms of Cx43 are endogenously produced via alternative translation from internal start codons in addition to full length Cx43, all from the same mRNA produced by the gene GJA1. GJA1-11k, the 11kDa alternatively translated isoform of Cx43, does not have a known role in the formation of gap junction channels, and little is known about its function. Here, we report that over expressed GJA1-11k, unlike the other five truncated isoforms, preferentially localizes to the nucleus in HEK293FT cells and suppresses cell growth by limiting cell cycle progression from the G0/G1 phase to the S phase. Furthermore, these functions are independent of the channel-forming full-length Cx43 isoform. Understanding the apparently unique role of GJA1-11k and its generation in cell cycle regulation may uncover a new target for affecting cell growth in multiple disease models.
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Affiliation(s)
- Irina Epifantseva
- Smidt Heart Institute, Graduate Program in Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (I.E.); (S.X.); (R.E.B.); (T.H.)
| | - Shaohua Xiao
- Smidt Heart Institute, Graduate Program in Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (I.E.); (S.X.); (R.E.B.); (T.H.)
| | - Rachel E. Baum
- Smidt Heart Institute, Graduate Program in Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (I.E.); (S.X.); (R.E.B.); (T.H.)
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - André G. Kléber
- Department of Pathology, Beth Israel & Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA;
| | - TingTing Hong
- Smidt Heart Institute, Graduate Program in Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (I.E.); (S.X.); (R.E.B.); (T.H.)
- Department of Medicine, University of California Los Angeles, Los Angeles, CA 90048, USA
| | - Robin M. Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA
- Correspondence: ; Tel.: +(801)-587-5845
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33
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Translating Translation to Mechanisms of Cardiac Hypertrophy. J Cardiovasc Dev Dis 2020; 7:jcdd7010009. [PMID: 32164190 PMCID: PMC7151157 DOI: 10.3390/jcdd7010009] [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: 01/26/2020] [Revised: 03/02/2020] [Accepted: 03/05/2020] [Indexed: 12/18/2022] Open
Abstract
Cardiac hypertrophy in response to chronic pathological stress is a common feature occurring with many forms of heart disease. This pathological hypertrophic growth increases the risk for arrhythmias and subsequent heart failure. While several factors promoting cardiac hypertrophy are known, the molecular mechanisms governing the progression to heart failure are incompletely understood. Recent studies on altered translational regulation during pathological cardiac hypertrophy are contributing to our understanding of disease progression. In this brief review, we describe how the translational machinery is modulated for enhanced global and transcript selective protein synthesis, and how alternative modes of translation contribute to the disease state. Attempts at controlling translational output through targeting of mTOR and its regulatory components are detailed, as well as recently emerging targets for pre-clinical investigation.
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34
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Chen W, Zheng P, Hong T, Wang Y, Liu N, He B, Zou S, Ren D, Duan J, Zhao L, Feng J. Astrocytes‐derived exosomes induce neuronal recovery after traumatic brain injury via delivering gap junction alpha 1‐20 k. J Tissue Eng Regen Med 2020; 14:412-423. [PMID: 31826322 DOI: 10.1002/term.3002] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/21/2019] [Accepted: 11/11/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Wei Chen
- Emergency Trauma CenterThe First Affiliated Hospital of Nanchang University Nanchang China
| | - Ping Zheng
- Department of NeurosurgeryThe People's Hospital of Shanghai Pudong New Area Affiliated to Shanghai University of Medicine and Health Sciences Shanghai China
| | - Tao Hong
- Emergency Trauma CenterThe First Affiliated Hospital of Nanchang University Nanchang China
| | - Yang Wang
- Emergency Trauma CenterThe First Affiliated Hospital of Nanchang University Nanchang China
| | - Ning Liu
- Department of NeurosurgeryThe First Affiliated Hospital of Nanjing Medical University Nanjing China
| | - Bin He
- Department of NeurosurgeryThe People's Hospital of Shanghai Pudong New Area Affiliated to Shanghai University of Medicine and Health Sciences Shanghai China
| | - Shufeng Zou
- Emergency Trauma CenterThe First Affiliated Hospital of Nanchang University Nanchang China
| | - Dabin Ren
- Department of NeurosurgeryThe People's Hospital of Shanghai Pudong New Area Affiliated to Shanghai University of Medicine and Health Sciences Shanghai China
| | - Jian Duan
- Emergency Trauma CenterThe First Affiliated Hospital of Nanchang University Nanchang China
| | - Lin Zhao
- Department of NeurosurgeryThe First Affiliated Hospital of Nanjing Medical University Nanjing China
| | - Jiugeng Feng
- Emergency Trauma CenterThe First Affiliated Hospital of Nanchang University Nanchang China
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35
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Totland MZ, Rasmussen NL, Knudsen LM, Leithe E. Regulation of gap junction intercellular communication by connexin ubiquitination: physiological and pathophysiological implications. Cell Mol Life Sci 2020; 77:573-591. [PMID: 31501970 PMCID: PMC7040059 DOI: 10.1007/s00018-019-03285-0] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 08/10/2019] [Accepted: 08/16/2019] [Indexed: 12/15/2022]
Abstract
Gap junctions consist of arrays of intercellular channels that enable adjacent cells to communicate both electrically and metabolically. Gap junctions have a wide diversity of physiological functions, playing critical roles in both excitable and non-excitable tissues. Gap junction channels are formed by integral membrane proteins called connexins. Inherited or acquired alterations in connexins are associated with numerous diseases, including heart failure, neuropathologies, deafness, skin disorders, cataracts and cancer. Gap junctions are highly dynamic structures and by modulating the turnover rate of connexins, cells can rapidly alter the number of gap junction channels at the plasma membrane in response to extracellular or intracellular cues. Increasing evidence suggests that ubiquitination has important roles in the regulation of endoplasmic reticulum-associated degradation of connexins as well as in the modulation of gap junction endocytosis and post-endocytic sorting of connexins to lysosomes. In recent years, researchers have also started to provide insights into the physiological roles of connexin ubiquitination in specific tissue types. This review provides an overview of the advances made in understanding the roles of connexin ubiquitination in the regulation of gap junction intercellular communication and discusses the emerging physiological and pathophysiological implications of these processes.
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Affiliation(s)
- Max Zachrisson Totland
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, 0424, Oslo, Norway
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
| | - Nikoline Lander Rasmussen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, 0424, Oslo, Norway
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
- Department of Medical Biology, University of Tromsø, Tromsø, Norway
| | - Lars Mørland Knudsen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, 0424, Oslo, Norway
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
| | - Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, 0424, Oslo, Norway.
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway.
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36
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Hautefort A, Pfenniger A, Kwak BR. Endothelial connexins in vascular function. VASCULAR BIOLOGY 2019; 1:H117-H124. [PMID: 32923963 PMCID: PMC7439941 DOI: 10.1530/vb-19-0015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 11/07/2019] [Indexed: 12/22/2022]
Abstract
Gap junctions are essential for intercellular crosstalk in blood and lymphatic vasculature. These clusters of intercellular channels ensure direct communication among endothelial cells and between endothelial and smooth muscle cells, and the synchronization of their behavior along the vascular tree. Gap junction channels are formed by connexins; six connexins form a connexon or hemichannel and the docking of two connexons result in a full gap junction channel allowing for the exchange of ions and small metabolites between neighboring cells. Recent evidence indicates that the intracellular domains of connexins may also function as an interaction platform (interactome) for other proteins, thereby regulating their function. Interestingly, fragments of Cx proteins generated by alternative internal translation were recently described, although their functions in the vascular wall remain to be uncovered. Variations in connexin expression are observed along different types of blood and lymphatic vessels; the most commonly found endothelial connexins are Cx37, Cx40, Cx43 and Cx47. Physiological studies on connexin-knockout mice demonstrated the essential roles of these channel-forming proteins in the coordination of vasomotor activity, endothelial permeability and inflammation, angiogenesis and in the maintenance of fluid balance in the body.
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Affiliation(s)
- Aurélie Hautefort
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Anna Pfenniger
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.,Department of Medical Specializations - Cardiology, University of Geneva, Geneva, Switzerland
| | - Brenda R Kwak
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.,Department of Medical Specializations - Cardiology, University of Geneva, Geneva, Switzerland
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37
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Opposite Effects of Moderate and Extreme Cx43 Deficiency in Conditional Cx43-Deficient Mice on Angiotensin II-Induced Cardiac Fibrosis. Cells 2019; 8:cells8101299. [PMID: 31652649 PMCID: PMC6830333 DOI: 10.3390/cells8101299] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/18/2019] [Accepted: 10/21/2019] [Indexed: 01/27/2023] Open
Abstract
Connexin 43 (Cx43) is essential for cardiac electrical coupling, but its effects on myocardial fibrosis is controversial. Here, we analyzed the role of Cx43 in myocardial fibrosis caused by angiotensin II (AngII) using Cx43fl/fl and Cx43Cre-ER(T)/fl inducible knock-out (Cx43 content: 50%) mice treated with vehicle or 4-hydroxytamoxifen (4-OHT) to induce a Cre-ER(T)-mediated global deletion of the Cx43 floxed allele. Myocardial collagen content was enhanced by AngII in all groups (n = 8–10/group, p < 0.05). However, animals with partial Cx43 deficiency (vehicle-treated Cx43Cre-ER(T)/fl) had a significantly higher AngII-induced collagen accumulation that reverted when treated with 4-OHT, which abolished Cx43 expression. The exaggerated fibrotic response to AngII in partially deficient Cx43Cre-ER(T)/fl mice was associated with enhanced p38 MAPK activation and was not evident in Cx43 heterozygous (Cx43+/-) mice. In contrast, normalization of interstitial collagen in 4-OHT-treated Cx43Cre-ER(T)/fl animals correlated with enhanced MMP-9 activity, IL-6 and NOX2 mRNA expression, and macrophage content, and with reduced α-SMA and SM22α in isolated fibroblasts. In conclusion, our data demonstrates an exaggerated, p38 MAPK-dependent, fibrotic response to AngII in partially deficient Cx43Cre-ER(T)/fl mice, and a paradoxical normalization of collagen deposition in animals with an almost complete Cx43 ablation, an effect associated with increased MMP-9 activity and inflammatory response and reduced fibroblasts differentiation.
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38
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Martins-Marques T, Ribeiro-Rodrigues T, Batista-Almeida D, Aasen T, Kwak BR, Girao H. Biological Functions of Connexin43 Beyond Intercellular Communication. Trends Cell Biol 2019; 29:835-847. [PMID: 31358412 DOI: 10.1016/j.tcb.2019.07.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 06/27/2019] [Accepted: 07/01/2019] [Indexed: 12/13/2022]
Abstract
Connexin43 (Cx43) is commonly associated with direct cell-cell communication through gap junctions (GJs). However, recent groundbreaking studies have challenged this dogma, implicating Cx43 in other biological processes, such as transcription, metabolism, autophagy, and ion channel trafficking. How Cx43 participates in these processes remains largely unknown, although its high turnover rate, capacity to bind to myriad proteins, and the discovery of truncated isoforms of Cx43, ascribe to this protein unanticipated roles in chief processes that require fine-tuned regulation. Accordingly, Cx43 can be regarded as a central integrative hub to which diverse cues converge to be processed in a concerted manner. In this review, we examine the noncanonical roles of Cx43 and discuss the implications of these functions in human diseases and future therapeutic strategies.
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Affiliation(s)
- Tania Martins-Marques
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Portugal
| | - Teresa Ribeiro-Rodrigues
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Portugal
| | - Daniela Batista-Almeida
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Portugal
| | - Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, Barcelona, Spain
| | - Brenda R Kwak
- Department of Pathology and Immunology, University of Geneva, CH-1211 Geneva, Switzerland
| | - Henrique Girao
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Portugal.
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Aasen T, Leithe E, Graham SV, Kameritsch P, Mayán MD, Mesnil M, Pogoda K, Tabernero A. Connexins in cancer: bridging the gap to the clinic. Oncogene 2019; 38:4429-4451. [PMID: 30814684 PMCID: PMC6555763 DOI: 10.1038/s41388-019-0741-6] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/26/2019] [Accepted: 01/26/2019] [Indexed: 02/08/2023]
Abstract
Gap junctions comprise arrays of intercellular channels formed by connexin proteins and provide for the direct communication between adjacent cells. This type of intercellular communication permits the coordination of cellular activities and plays key roles in the control of cell growth and differentiation and in the maintenance of tissue homoeostasis. After more than 50 years, deciphering the links among connexins, gap junctions and cancer, researchers are now beginning to translate this knowledge to the clinic. The emergence of new strategies for connexin targeting, combined with an improved understanding of the molecular bases underlying the dysregulation of connexins during cancer development, offers novel opportunities for clinical applications. However, different connexin isoforms have diverse channel-dependent and -independent functions that are tissue and stage specific. This can elicit both pro- and anti-tumorigenic effects that engender significant challenges in the path towards personalised medicine. Here, we review the current understanding of the role of connexins and gap junctions in cancer, with particular focus on the recent progress made in determining their prognostic and therapeutic potential.
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Affiliation(s)
- Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, Barcelona, Spain.
| | - Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital and K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
| | - Sheila V Graham
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Petra Kameritsch
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, München, Germany
| | - María D Mayán
- CellCOM Research Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), University of A Coruña, A Coruña, Spain
| | - Marc Mesnil
- STIM Laboratory, Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers, France
| | - Kristin Pogoda
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, München, Germany
| | - Arantxa Tabernero
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain.
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40
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Aasen T, Sansano I, Montero MÁ, Romagosa C, Temprana-Salvador J, Martínez-Marti A, Moliné T, Hernández-Losa J, Ramón y Cajal S. Insight into the Role and Regulation of Gap Junction Genes in Lung Cancer and Identification of Nuclear Cx43 as a Putative Biomarker of Poor Prognosis. Cancers (Basel) 2019; 11:cancers11030320. [PMID: 30845770 PMCID: PMC6468764 DOI: 10.3390/cancers11030320] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 02/25/2019] [Accepted: 03/02/2019] [Indexed: 12/12/2022] Open
Abstract
Direct intercellular communication, mediated by gap junctions formed by the connexin transmembrane protein family, is frequently dysregulated in cancer. Connexins have been described as tumour suppressors, but emerging evidence suggests that they can also act as tumour promoters. This feature is connexin- and tissue-specific and may be mediated by complex signalling pathways through gap junctions or hemichannels or by completely junction-independent events. Lung cancer is the number one cancer in terms of mortality worldwide, and novel biomarkers and therapeutic targets are urgently needed. Our objective was to gain a better understanding of connexins in this setting. We used several in silico tools to analyse TCGA data in order to compare connexin mRNA expression between healthy lung tissue and lung tumours and correlated these results with gene methylation patterns. Using Kaplan-Meier plotter tools, we analysed a microarray dataset and an RNA-seq dataset of non-small cell lung tumours in order to correlate connexin expression with patient prognosis. We found that connexin mRNA expression is frequently either upregulated or downregulated in lung tumours. This correlated with both good and poor prognosis (overall survival) in a clear connexin isoform-dependent manner. These associations were strongly influenced by the histological subtype (adenocarcinoma versus squamous cell carcinoma). We present an overview of all connexins but particularly focus on four isoforms implicated in lung cancer: Cx26, Cx30.3, Cx32 and Cx43. We further analysed the protein expression and localization of Cx43 in a series of 73 human lung tumours. We identified a subset of tumours that exhibited a unique strong nuclear Cx43 expression pattern that predicted worse overall survival (p = 0.014). Upon sub-stratification, the prognostic value remained highly significant in the adenocarcinoma subtype (p = 0.002) but not in the squamous carcinoma subtype (p = 0.578). This finding highlights the importance of analysis of connexin expression at the protein level, particularly the subcellular localization. Elucidation of the underlying pathways regulating Cx43 localization may provide for novel therapeutic opportunities.
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Affiliation(s)
- Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Research Institute (VHIR), Barcelona 08035, Spain.
| | - Irene Sansano
- Pathology Department, Vall d'Hebron University Hospital, Barcelona 08035, Spain.
| | | | - Cleofé Romagosa
- Pathology Department, Vall d'Hebron University Hospital, Barcelona 08035, Spain.
| | | | | | - Teresa Moliné
- Pathology Department, Vall d'Hebron University Hospital, Barcelona 08035, Spain.
| | | | - Santiago Ramón y Cajal
- Translational Molecular Pathology, Vall d'Hebron Research Institute (VHIR), Barcelona 08035, Spain.
- Pathology Department, Vall d'Hebron University Hospital, Barcelona 08035, Spain.
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41
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Denis JF, Diagbouga MR, Molica F, Hautefort A, Linnerz T, Watanabe M, Lemeille S, Bertrand JY, Kwak BR. KLF4-Induced Connexin40 Expression Contributes to Arterial Endothelial Quiescence. Front Physiol 2019; 10:80. [PMID: 30809154 PMCID: PMC6379456 DOI: 10.3389/fphys.2019.00080] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/24/2019] [Indexed: 12/11/2022] Open
Abstract
Shear stress, a blood flow-induced frictional force, is essential in the control of endothelial cell (EC) homeostasis. High laminar shear stress (HLSS), as observed in straight parts of arteries, assures a quiescent non-activated endothelium through the induction of Krüppel-like transcription factors (KLFs). Connexin40 (Cx40)-mediated gap junctional communication is known to contribute to a healthy endothelium by propagating anti-inflammatory signals between ECs, however, the molecular basis of the transcriptional regulation of Cx40 as well as its downstream effectors remain poorly understood. Here, we show that flow-induced KLF4 regulated Cx40 expression in a mouse EC line. Chromatin immunoprecipitation in ECs revealed that KLF4 bound to three predicted KLF consensus binding sites in the Cx40 promoter. HLSS-dependent induction of Cx40 expression was confirmed in primary human ECs. The downstream effects of Cx40 modulation in ECs exposed to HLSS were elucidated by an unbiased transcriptomics approach. Cell cycle progression was identified as an important downstream target of Cx40 under HLSS. In agreement, an increase in the proportion of proliferating cell nuclear antigen (PCNA)-positive ECs and a decrease in the proportion of ECs in the G0/G1 phase were observed under HLSS after Cx40 silencing. Transfection of communication-incompetent HeLa cells with Cx40 demonstrated that the regulation of proliferation by Cx40 was not limited to ECs. Using a zebrafish model, we finally showed faster intersegmental vessel growth and branching into the dorsal longitudinal anastomotic vessel in embryos knock-out for the Cx40 orthologs Cx41.8 and Cx45.6. Most significant effects were observed in embryos with a mutant Cx41.8 encoding for a channel with reduced gap junctional function. Faster intersegmental vessel growth in Cx41.8 mutant embryos was associated with increased EC proliferation as assessed by PH3 immunostaining. Our data shows a novel evolutionary-conserved role of flow-driven KLF4-dependent Cx40 expression in endothelial quiescence that may be relevant for the control of atherosclerosis and diseases involving sprouting angiogenesis.
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Affiliation(s)
- Jean-François Denis
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | | | - Filippo Molica
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Aurélie Hautefort
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Tanja Linnerz
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | | | - Sylvain Lemeille
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Julien Y Bertrand
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Brenda R Kwak
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.,Department of Medical Specializations - Cardiology, University of Geneva, Geneva, Switzerland
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42
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Kameritsch P, Kiemer F, Mannell H, Beck H, Pohl U, Pogoda K. PKA negatively modulates the migration enhancing effect of Connexin 43. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:828-838. [PMID: 30769008 DOI: 10.1016/j.bbamcr.2019.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 12/22/2022]
Abstract
Connexin 43 (Cx43) expression is associated with an increased cell migration and related changes of the actin cytoskeleton (enhanced filopodia formation). These effects are mediated by the C-terminal cytoplasmic part of Cx43 in a channel-independent manner. Since this part has been shown to interact with a variety of proteins and has multiple phosphorylation sites we analyzed here a potential role of the protein kinase A (PKA) for the Cx43 mediated increase in cell migration. Mutation of the PKA-phosphorylation site (substitution of three serines by alanine or glycine) resulted in a further increase in cell motility compared to wild-type Cx43, but with a loss of directionality. Likewise, cell motility was enhanced by PKA inhibition only in Cx43 expressing cells, while reduced in the presence of the PKA activator forskolin. In contrast, cell motility remained unaffected by stimulation with forskolin in cells expressing Cx43 with the mutated PKA phosphorylation site (Cx43-PKA) as well as in Cx-deficient cells. Moreover, PKA activation resulted in increased binding of PKA and VASP to Cx43 associated with an enhanced phosphorylation of VASP, an important regulatory protein of cell polarity and directed migration. Functionally, we could confirm these results in endothelial cells endogenously expressing Cx43. A Tat-Cx43 peptide containing the PKA phosphorylation site abolished the PKA dependent reduction in endothelial cell migration. Our results indicate that PKA dependent phosphorylation of Cx43 modulates cell motility and plays a pivotal role in regulating directed cell migration.
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Affiliation(s)
- Petra Kameritsch
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, Großhaderner Str. 9, 82152 Planegg, Martinsried, Germany; DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Biedersteiner Str. 29, 80802 München, Germany.
| | - Felizitas Kiemer
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, Großhaderner Str. 9, 82152 Planegg, Martinsried, Germany.
| | - Hanna Mannell
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, Großhaderner Str. 9, 82152 Planegg, Martinsried, Germany.
| | - Heike Beck
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, Großhaderner Str. 9, 82152 Planegg, Martinsried, Germany.
| | - Ulrich Pohl
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, Großhaderner Str. 9, 82152 Planegg, Martinsried, Germany; DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Biedersteiner Str. 29, 80802 München, Germany; Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Str. 17, 81377 München, Germany.
| | - Kristin Pogoda
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, Großhaderner Str. 9, 82152 Planegg, Martinsried, Germany; DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Biedersteiner Str. 29, 80802 München, Germany.
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43
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Connexin43 Suppresses Lung Cancer Stem Cells. Cancers (Basel) 2019; 11:cancers11020175. [PMID: 30717421 PMCID: PMC6406368 DOI: 10.3390/cancers11020175] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 01/30/2019] [Indexed: 02/07/2023] Open
Abstract
Alterations in gap junctions and their protein components, connexins, have been associated with neoplastic transformation and drug resistance, and more recently have been shown to play important roles in cancer stem cells (CSCs). However, there is less knowledge of connexins and gap junctions in lung CSCs. To address this, Connexin43 (Cx43), the major human lung epithelial gap junction protein, was expressed ectopically in poorly expressing National Cancer Institute-125 (NCI-H125) metastatic human lung adenocarcinoma cells, and phenotypic characteristics of malignant cells and abundance of CSCs were evaluated. The ectopic expression of Cx43 resulted in the formation of functional gap junctions; a more epithelial morphology; reduced proliferation, invasion, colony formation, tumorsphere formation, pluripotency marker expression, and percentage of aldehyde dehydrogenase (ALDH)-positive cells; and increased cisplatin sensitivity. Similarly, in NCI-H522 (human lung adenocarcinoma) and NCI-H661 (human lung large cell carcinoma) cell lines, which express Cx43 and functional gap junctions endogenously, the Cx43 content was lower in tumorspheres and ALDH-positive cells than in bulk cells. These results demonstrate that Cx43 can reverse several neoplastic characteristics and reduce the abundance of human lung CSCs.
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44
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Kubincová P, Sychrová E, Raška J, Basu A, Yawer A, Dydowiczová A, Babica P, Sovadinová I. Polycyclic Aromatic Hydrocarbons and Endocrine Disruption: Role of Testicular Gap Junctional Intercellular Communication and Connexins. Toxicol Sci 2019; 169:70-83. [DOI: 10.1093/toxsci/kfz023] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Abstract
Ambient air pollution and smoking are well-documented risk factors for male infertility. Prevalent air pollutants and cigarette smoke components, polycyclic aromatic hydrocarbons (PAHs), are environmental and occupational toxicants that act as chemicals disrupting endocrine regulation and reproductive potential in males. Testicular gap junctional intercellular communication (GJIC) is critical for normal development and function of testicular tissue, thus we assessed GJIC as a process potentially targeted by PAHs in testes. Lower MW PAHs with a bay or bay-like region rapidly dysregulated GJIC in Leydig TM3 cells by relocalization of major testicular gap junctional protein connexin 43 (Cx43) from plasma membrane to cytoplasm. This was associated with colocalization between Cx43 and ubiquitin in intracellular compartments, but without any effect on Cx43 degradation rate or steady-state Cx43 mRNA levels. A longer exposure to active PAHs decreased steady-state levels of full-length Cx43 protein and its 2 N-truncated isoforms. Inhibition of GJIC by PAHs, similarly to a prototypic GJIC-inhibitor TPA, was mediated via the MAP kinase-Erk1/2 and PKC pathways. Polycyclic aromatic hydrocarbon-induced GJIC dysregulation in testes was cell-type-specific because neither PAH dysregulated GJIC in Sertoli TM4 cells, despite PAHs were rapidly taken up by both Leydig TM3 as well as Sertoli TM4 cells. Because TPA effectively dysregulated GJIC in both testicular cell types, a unique regulator of GJIC targeted by PAHs might exist in Leydig TM3 cells. Our results indicate that PAHs could be a potential etiological agent contributing to reproductive dysfunctions in males through an impairment of testicular GJIC and junctional and/or nonjunctional functions of Cx43.
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Affiliation(s)
- Petra Kubincová
- Masaryk University, Faculty of Science, RECETOX, Brno, Czech Republic
| | - Eliška Sychrová
- Masaryk University, Faculty of Science, RECETOX, Brno, Czech Republic
| | - Jan Raška
- Masaryk University, Faculty of Science, RECETOX, Brno, Czech Republic
| | - Amrita Basu
- Masaryk University, Faculty of Science, RECETOX, Brno, Czech Republic
| | - Affiefa Yawer
- Masaryk University, Faculty of Science, RECETOX, Brno, Czech Republic
| | - Aneta Dydowiczová
- Masaryk University, Faculty of Science, RECETOX, Brno, Czech Republic
| | - Pavel Babica
- Masaryk University, Faculty of Science, RECETOX, Brno, Czech Republic
| | - Iva Sovadinová
- Masaryk University, Faculty of Science, RECETOX, Brno, Czech Republic
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45
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Pogoda K, Kameritsch P, Mannell H, Pohl U. Connexins in the control of vasomotor function. Acta Physiol (Oxf) 2019; 225:e13108. [PMID: 29858558 DOI: 10.1111/apha.13108] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 05/25/2018] [Accepted: 05/28/2018] [Indexed: 12/13/2022]
Abstract
Vascular endothelial cells, as well as smooth muscle cells, show heterogeneity with regard to their receptor expression and reactivity. For the vascular wall to act as a functional unit, the various cells' responses require integration. Such an integration is not only required for a homogeneous response of the vascular wall, but also for the vasomotor behaviour of consecutive segments of the microvascular arteriolar tree. As flow resistances of individual sections are connected in series, sections require synchronization and coordination to allow effective changes of conductivity and blood flow. A prerequisite for the local coordination of individual vascular cells and different sections of an arteriolar tree is intercellular communication. Connexins are involved in a dual manner in this coordination. (i) By forming gap junctions between cells, they allow an intercellular exchange of signalling molecules and electrical currents. In particular, the spread of electrical currents allows for coordination of cell responses over longer distances. (ii) Connexins are able to interact with other proteins to form signalling complexes. In this way, they can modulate and integrate individual cells' responses also in a channel-independent manner. This review outlines mechanisms allowing the vascular connexins to exert their coordinating function and to regulate the vasomotor reactions of blood vessels both locally, and in vascular networks. Wherever possible, we focus on the vasomotor behaviour of small vessels and arterioles which are the main vessels determining vascular resistance, blood pressure and local blood flow.
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Affiliation(s)
- K. Pogoda
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
- DZHK (German Center for Cardiovascular Research); Partner Site Munich Heart Alliance; Munich Germany
| | - P. Kameritsch
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
- DZHK (German Center for Cardiovascular Research); Partner Site Munich Heart Alliance; Munich Germany
| | - H. Mannell
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
| | - U. Pohl
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
- DZHK (German Center for Cardiovascular Research); Partner Site Munich Heart Alliance; Munich Germany
- Munich Cluster for Systems Neurology (SyNergy); Munich Germany
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46
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Basheer WA, Fu Y, Shimura D, Xiao S, Agvanian S, Hernandez DM, Hitzeman TC, Hong T, Shaw RM. Stress response protein GJA1-20k promotes mitochondrial biogenesis, metabolic quiescence, and cardioprotection against ischemia/reperfusion injury. JCI Insight 2018; 3:121900. [PMID: 30333316 DOI: 10.1172/jci.insight.121900] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 09/11/2018] [Indexed: 01/23/2023] Open
Abstract
Connexin 43 (Cx43), a product of the GJA1 gene, is a gap junction protein facilitating intercellular communication between cardiomyocytes. Cx43 protects the heart from ischemic injury by mechanisms that are not well understood. GJA1 mRNA can undergo alternative translation, generating smaller isoforms in the heart, with GJA1-20k being the most abundant. Here, we report that ischemic and ischemia/reperfusion (I/R) injuries upregulate endogenous GJA1-20k protein in the heart, which targets to cardiac mitochondria and associates with the outer mitochondrial membrane. Exploring the functional consequence of increased GJA1-20k, we found that AAV9-mediated gene transfer of GJA1-20k in mouse hearts increases mitochondrial biogenesis while reducing mitochondrial membrane potential, respiration, and ROS production. By doing so, GJA1-20k promotes a protective mitochondrial phenotype, as seen with ischemic preconditioning (IPC), which also increases endogenous GJA1-20k in heart lysates and mitochondrial fractions. As a result, AAV9-GJA1-20k pretreatment reduces myocardial infarct size in mouse hearts subjected to in vivo ischemic injury or ex vivo I/R injury, similar to an IPC-induced cardioprotective effect. In conclusion, GJA1-20k is an endogenous stress response protein that induces mitochondrial biogenesis and metabolic hibernation, preconditioning the heart against I/R insults. Introduction of exogenous GJA1-20k is a putative therapeutic strategy for patients undergoing anticipated ischemic injury.
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Affiliation(s)
- Wassim A Basheer
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Ying Fu
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Daisuke Shimura
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Shaohua Xiao
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Sosse Agvanian
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Diana M Hernandez
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Tara C Hitzeman
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - TingTing Hong
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.,Department of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, California
| | - Robin M Shaw
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.,Department of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, California
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47
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James CC, Smyth JW. Alternative mechanisms of translation initiation: An emerging dynamic regulator of the proteome in health and disease. Life Sci 2018; 212:138-144. [PMID: 30290184 DOI: 10.1016/j.lfs.2018.09.054] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 09/18/2018] [Accepted: 09/27/2018] [Indexed: 01/06/2023]
Abstract
Eukaryotic mRNAs were historically thought to rely exclusively on recognition and binding of their 5' cap by initiation factors to effect protein translation. While internal ribosome entry sites (IRESs) are well accepted as necessary for the cap-independent translation of many viral genomes, there is now recognition that eukaryotic mRNAs also undergo non-canonical modes of translation initiation. Recently, high-throughput assays have identified thousands of mammalian transcripts with translation initiation occurring at non-canonical start codons, upstream of and within protein coding regions. In addition to IRES-mediated events, regulatory mechanisms of translation initiation have been described involving alternate 5' cap recognition, mRNA sequence elements, and ribosome selection. These mechanisms ensure translation of specific mRNAs under conditions where cap-dependent translation is shut down and contribute to pathological states including cardiac hypertrophy and cancer. Such global and gene-specific dynamic regulation of translation presents us with an increasing number of novel therapeutic targets. While these newly discovered modes of translation initiation have been largely studied in isolation, it is likely that several act on the same mRNA and exquisite coordination is necessary to maintain 'normal' translation. In this short review, we summarize the current state of knowledge of these alternative mechanisms of eukaryotic protein translation, their contribution to normal and pathological cell biology, and the potential of targeting translation initiation therapeutically in human disease.
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Affiliation(s)
- Carissa C James
- Virginia Tech Carilion Research Institute and School of Medicine, Roanoke, VA, USA; Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA, USA; Center for Heart and Regenerative Medicine, Virginia Tech Carilion Research Institute, Roanoke, VA, USA
| | - James W Smyth
- Virginia Tech Carilion Research Institute and School of Medicine, Roanoke, VA, USA; Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; Center for Heart and Regenerative Medicine, Virginia Tech Carilion Research Institute, Roanoke, VA, USA.
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48
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Gap junction protein Connexin-43 is a direct transcriptional regulator of N-cadherin in vivo. Nat Commun 2018; 9:3846. [PMID: 30242148 PMCID: PMC6155008 DOI: 10.1038/s41467-018-06368-x] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/29/2018] [Indexed: 11/16/2022] Open
Abstract
Connexins are the primary components of gap junctions, providing direct links between cells under many physiological processes. Here, we demonstrate that in addition to this canonical role, Connexins act as transcriptional regulators. We show that Connexin 43 (Cx43) controls neural crest cell migration in vivo by directly regulating N-cadherin transcription. This activity requires interaction between Cx43 carboxy tail and the basic transcription factor-3, which drives the translocation of Cx43 tail to the nucleus. Once in the nucleus they form a complex with PolII which directly binds to the N-cadherin promoter. We found that this mechanism is conserved between amphibian and mammalian cells. Given the strong evolutionary conservation of connexins across vertebrates, this may reflect a common mechanism of gene regulation by a protein whose function was previously ascribed only to gap junctional communication. Connexins are components of gap junctions that link cells and allow intercellular communication. Here, the authors show that the Connexin 43 carboxy tail interacts with basic transcription factor-3, leading to nuclear translocation and direct regulation of N-cadherin expression and neural crest migration.
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49
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Basheer WA, Shaw RM. Connexin 43 and CaV1.2 Ion Channel Trafficking in Healthy and Diseased Myocardium. Circ Arrhythm Electrophysiol 2018; 9:e001357. [PMID: 27266274 DOI: 10.1161/circep.115.001357] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 04/29/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Wassim A Basheer
- From the Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA (W.A.B., R.M.S.); and Department of Medicine, University of California Los Angeles (R.M.S.)
| | - Robin M Shaw
- From the Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA (W.A.B., R.M.S.); and Department of Medicine, University of California Los Angeles (R.M.S.).
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50
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Aasen T, Johnstone S, Vidal-Brime L, Lynn KS, Koval M. Connexins: Synthesis, Post-Translational Modifications, and Trafficking in Health and Disease. Int J Mol Sci 2018; 19:ijms19051296. [PMID: 29701678 PMCID: PMC5983588 DOI: 10.3390/ijms19051296] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/20/2018] [Accepted: 04/21/2018] [Indexed: 02/06/2023] Open
Abstract
Connexins are tetraspan transmembrane proteins that form gap junctions and facilitate direct intercellular communication, a critical feature for the development, function, and homeostasis of tissues and organs. In addition, a growing number of gap junction-independent functions are being ascribed to these proteins. The connexin gene family is under extensive regulation at the transcriptional and post-transcriptional level, and undergoes numerous modifications at the protein level, including phosphorylation, which ultimately affects their trafficking, stability, and function. Here, we summarize these key regulatory events, with emphasis on how these affect connexin multifunctionality in health and disease.
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Affiliation(s)
- Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain.
| | - Scott Johnstone
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VI 22908, USA.
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TT, UK.
| | - Laia Vidal-Brime
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain.
| | - K Sabrina Lynn
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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