1
|
Huang C, Liu X, Feng Y, Xiao Z, Lu Z, Wang L, Ming J. Bibliometric analysis and visualization of Connexin 43 in the field of solid tumor research(2000-2024). Front Immunol 2025; 16:1588828. [PMID: 40416989 PMCID: PMC12098641 DOI: 10.3389/fimmu.2025.1588828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2025] [Accepted: 04/21/2025] [Indexed: 05/27/2025] Open
Abstract
Background Connexin 43 (Cx43) plays a pivotal role in tumor growth, metastasis, and disease progression. This study employs bibliometric analysis to identify key research trends and emerging hotspots in Cx43-related solid tumor research. Methods In December 2024, the Web of Science Core Collection (WoSCC) database was searched for publications on Cx43 in solid tumor research from 2000 to 2024. Bibliometric analysis and data visualization were primarily conducted using CiteSpace, VOSviewer, and Bibliometrix, with a focus on visualizing aspects such as countries, institutions, journals, authors, references, and keywords in the field. Results A total of 1,666 publications were retrieved, with the annual number of articles and citations continuing to grow. The United States and China had the highest number of publications, while the University of Western Ontario in Canada was the leading institution, with the most publications by Christian C.G. Nau. Lampe, P.D. was the most cited author. The International Journal of Molecular Sciences was the most frequently published journal, and the Journal of Biological Chemistry was the most frequently co-cited journal. High-frequency keywords included phosphorylation, breast cancer, gastric cancer, prognostic markers, anti-tumor immune response, and drug resistance. Conclusion Contemporary research focuses on the role of Cx43 phosphorylation in tumorigenesis, progression, and metastasis, its potential as a prognostic biomarker, and its critical role as an immunotherapeutic target and in tumor drug resistance. These studies provide a comprehensive analysis for a deeper understanding of the role of Cx43 in solid tumors and help to promote further research in this area.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Jia Ming
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing
Medical University, Chongqing, China
| |
Collapse
|
2
|
Yaghoobi A, Rezaee M, Hedayati N, Keshavarzmotamed A, Khalilzad MA, Russel R, Asemi Z, Rajabi Moghadam H, Mafi A. Insight into the cardioprotective effects of melatonin: shining a spotlight on intercellular Sirt signaling communication. Mol Cell Biochem 2025; 480:799-823. [PMID: 38980593 DOI: 10.1007/s11010-024-05002-3] [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: 11/30/2023] [Accepted: 03/25/2024] [Indexed: 07/10/2024]
Abstract
Cardiovascular diseases (CVDs) are the leading causes of death and illness worldwide. While there have been advancements in the treatment of CVDs using medication and medical procedures, these conventional methods have limited effectiveness in halting the progression of heart diseases to complete heart failure. However, in recent years, the hormone melatonin has shown promise as a protective agent for the heart. Melatonin, which is secreted by the pineal gland and regulates our sleep-wake cycle, plays a role in various biological processes including oxidative stress, mitochondrial function, and cell death. The Sirtuin (Sirt) family of proteins has gained attention for their involvement in many cellular functions related to heart health. It has been well established that melatonin activates the Sirt signaling pathways, leading to several beneficial effects on the heart. These include preserving mitochondrial function, reducing oxidative stress, decreasing inflammation, preventing cell death, and regulating autophagy in cardiac cells. Therefore, melatonin could play crucial roles in ameliorating various cardiovascular pathologies, such as sepsis, drug toxicity-induced myocardial injury, myocardial ischemia-reperfusion injury, hypertension, heart failure, and diabetic cardiomyopathy. These effects may be partly attributed to the modulation of different Sirt family members by melatonin. This review summarizes the existing body of literature highlighting the cardioprotective effects of melatonin, specifically the ones including modulation of Sirt signaling pathways. Also, we discuss the potential use of melatonin-Sirt interactions as a forthcoming therapeutic target for managing and preventing CVDs.
Collapse
Affiliation(s)
- Alireza Yaghoobi
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Malihe Rezaee
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Neda Hedayati
- School of Medicine, Iran University of Medical Science, Tehran, Iran
| | | | | | - Reitel Russel
- Department of Cell Systems and Anatomy, UT Health. Long School of Medicine, San Antonio, TX, USA.
| | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran.
| | - Hasan Rajabi Moghadam
- Department of Cardiology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran
| | - Alireza Mafi
- Department of Clinical Biochemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
- Nutrition and Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
| |
Collapse
|
3
|
Fournier S, Clarhaut J, Cronier L, Monvoisin A. GJA1-20k, a Short Isoform of Connexin43, from Its Discovery to Its Potential Implication in Cancer Progression. Cells 2025; 14:180. [PMID: 39936974 PMCID: PMC11817742 DOI: 10.3390/cells14030180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2024] [Revised: 01/20/2025] [Accepted: 01/22/2025] [Indexed: 02/13/2025] Open
Abstract
The Connexin43 transmembrane protein (Cx43), encoded by the GJA1 gene, is a member of a multigenic family of proteins that oligomerize to form hemichannels and intercellular channels, allowing gap junctional intercellular communication between adjacent cells or communication between the intracellular and extracellular compartments. Cx43 has long been shown to play a significant but complex role in cancer development, acting as a tumor suppressor and/or tumor promoter. The effects of Cx43 are associated with both channel-dependent and -independent functionalities and differ depending on the expression level, subcellular location and the considered stage of cancer progression. Recently, six isoforms of Cx43 have been described and one of them, called GJA1-20k, has also been found to be expressed in cancer cells. This isoform is generated by alternative translation and corresponds to the end part of the fourth transmembrane domain and the entire carboxyl-terminal (CT) domain. Initial studies in the cardiac model implicated GJA1-20k in the trafficking of full-length Cx43 to the plasma membrane, in cytoskeletal dynamics and in mitochondrial fission and subcellular distribution. As these processes are associated with cancer progression, a potential link between Cx43 functions, mitochondrial activity and GJA1-20k expression can be postulated in this context. This review synthetizes the current knowledge on GJA1-20k and its potential involvement in processes related to epithelial-to-mesenchymal transition (EMT) and the proliferation, dissemination and quiescence of cancer cells. Particular emphasis is placed on the putative roles of GJA1-20k in full-length Cx43 exportation to the plasma membrane, mitochondrial activity and functions originally attributed to the CT domain.
Collapse
Affiliation(s)
- Sarah Fournier
- Laboratory Channels and Connexins in Cancer and Cell Stemness (4CS), UR 22751, University of Poitiers, 1 Rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France;
| | - Jonathan Clarhaut
- Pharmacology of Antimicrobial Agents and Antibioresistance (PHAR2), INSERM U1070, University of Poitiers; 1 Rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France;
- University Hospital Center of Poitiers, 2 Rue de la Milétrie, 86021 Poitiers, France
| | - Laurent Cronier
- Laboratory Channels and Connexins in Cancer and Cell Stemness (4CS), UR 22751, University of Poitiers, 1 Rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France;
| | - Arnaud Monvoisin
- Laboratory Channels and Connexins in Cancer and Cell Stemness (4CS), UR 22751, University of Poitiers, 1 Rue Georges Bonnet, TSA 51106, CEDEX 09, 86073 Poitiers, France;
| |
Collapse
|
4
|
Maalouf M, Gaffney AT, Bell BR, Shaw RM. Exploring the Potent Roles of an Internally Translated Truncated Connexin-43 Isoform. BIOLOGY 2024; 13:1046. [PMID: 39765713 PMCID: PMC11672902 DOI: 10.3390/biology13121046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2024] [Revised: 12/10/2024] [Accepted: 12/12/2024] [Indexed: 01/11/2025]
Abstract
Connexins are a family of transmembrane proteins that form membrane channels [...].
Collapse
Affiliation(s)
| | | | | | - Robin M. Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84132, USA
| |
Collapse
|
5
|
Domingues N, Ribeiro-Rodrigues T, Girão H. Should it stay or should it go: gap junction protein GJA1/Cx43 conveys damaged lysosomes to the cell periphery to potentiate exocytosis. Autophagy 2024; 20:2816-2818. [PMID: 39394955 PMCID: PMC11587831 DOI: 10.1080/15548627.2024.2408711] [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: 07/25/2024] [Revised: 09/18/2024] [Accepted: 09/20/2024] [Indexed: 10/14/2024] Open
Abstract
GJA1/Cx43 (gap junction protein alpha 1) has long been associated with gap junctions-mediated communication between adjacent cells. However, recent data have defied this concept, with studies implicating GJA1 in other biological processes, such as macroautophagy/autophagy regulation, mitochondrial activity and extracellular vesicles biology. In our recent study we unveiled an additional role played by GJA1 in lysosomal trafficking. We demonstrate that GJA1 promotes the exocytosis of damaged lysosomes, through a mechanism that relies on ACTR2/ARP2-ACTR3/ARP3-dependent actin remodeling. Our findings ascribe to GJA1 an important role during pathogen infection and lysosomal storage disorders, favoring the release of dysfunctional lysosomes.
Collapse
Affiliation(s)
- Neuza Domingues
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University Coimbra, Coimbra, Portugal
- Faculty of Medicine, University Coimbra, Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University Coimbra, Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
| | - Teresa Ribeiro-Rodrigues
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University Coimbra, Coimbra, Portugal
- Faculty of Medicine, University Coimbra, Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University Coimbra, Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Henrique Girão
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University Coimbra, Coimbra, Portugal
- Faculty of Medicine, University Coimbra, Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University Coimbra, Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| |
Collapse
|
6
|
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. Stem Cell Res Ther 2024; 15:359. [PMID: 39390589 PMCID: PMC11468299 DOI: 10.1186/s13287-024-03932-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Accepted: 09/09/2024] [Indexed: 10/12/2024] Open
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 connexin 43 (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 h 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.
Collapse
Affiliation(s)
- Rebecca M Irwin
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Matthew A Thomas
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Megan J Fahey
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - María D Mayán
- CellCOM Research Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña (UDC), A Coruña, Spain
| | - James W Smyth
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, 24016, USA
- Center for Vascular and Heart Research, FBRI at VTC, Roanoke, VA, 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, 24016, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Michelle L Delco
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
| |
Collapse
|
7
|
Wu Q, Wang Y, Liu J, Guan X, Chang X, Liu Z, Liu R. Microtubules and cardiovascular diseases: insights into pathology and therapeutic strategies. Int J Biochem Cell Biol 2024; 175:106650. [PMID: 39237031 DOI: 10.1016/j.biocel.2024.106650] [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: 03/21/2024] [Revised: 08/25/2024] [Accepted: 08/31/2024] [Indexed: 09/07/2024]
Abstract
Microtubules, complex cytoskeletal structures composed of tubulin proteins in eukaryotic cells, have garnered recent attention in cardiovascular research. Investigations have focused on the post-translational modifications of tubulin, including acetylation and detyrosination. Perturbations in microtubule homeostasis have been implicated in various pathological processes associated with cardiovascular diseases such as heart failure, ischemic heart disease, and arrhythmias. Thus, elucidating the intricate interplay between microtubule dynamics and cardiovascular pathophysiology is imperative for advancing preventive and therapeutic strategies. Several natural compounds have been identified to potentially modulate microtubules, thereby exerting regulatory effects on cardiovascular diseases. This review synthesizes current literature to delineate the roles of microtubules in cardiovascular diseases and assesses the potential of natural compounds in microtubule-targeted therapies.
Collapse
Affiliation(s)
- Qiaomin Wu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Yanli Wang
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Jinfeng Liu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Xuanke Guan
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Xing Chang
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China.
| | - Zhiming Liu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Ruxiu Liu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China.
| |
Collapse
|
8
|
Domingues N, Catarino S, Cristóvão B, Rodrigues L, Carvalho FA, Sarmento MJ, Zuzarte M, Almeida J, Ribeiro-Rodrigues T, Correia-Rodrigues Â, Fernandes F, Rodrigues-Santos P, Aasen T, Santos NC, Korolchuk VI, Gonçalves T, Milosevic I, Raimundo N, Girão H. Connexin43 promotes exocytosis of damaged lysosomes through actin remodelling. EMBO J 2024; 43:3627-3649. [PMID: 39044100 PMCID: PMC11377567 DOI: 10.1038/s44318-024-00177-3] [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: 12/11/2023] [Revised: 07/04/2024] [Accepted: 07/09/2024] [Indexed: 07/25/2024] Open
Abstract
A robust and efficient cellular response to lysosomal membrane damage prevents leakage from the lysosome lumen into the cytoplasm. This response is understood to happen through either lysosomal membrane repair or lysophagy. Here we report exocytosis as a third response mechanism to lysosomal damage, which is further potentiated when membrane repair or lysosomal degradation mechanisms are impaired. We show that Connexin43 (Cx43), a protein canonically associated with gap junctions, is recruited from the plasma membrane to damaged lysosomes, promoting their secretion and accelerating cell recovery. The effects of Cx43 on lysosome exocytosis are mediated by a reorganization of the actin cytoskeleton that increases plasma membrane fluidity and decreases cell stiffness. Furthermore, we demonstrate that Cx43 interacts with the actin nucleator Arp2, the activity of which was shown to be necessary for Cx43-mediated actin rearrangement and lysosomal exocytosis following damage. These results define a novel mechanism of lysosomal quality control whereby Cx43-mediated actin remodelling potentiates the secretion of damaged lysosomes.
Collapse
Affiliation(s)
- Neuza Domingues
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
| | - Steve Catarino
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Beatriz Cristóvão
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Lisa Rodrigues
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Filomena A Carvalho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Maria João Sarmento
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Mónica Zuzarte
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Jani Almeida
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Teresa Ribeiro-Rodrigues
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Ânia Correia-Rodrigues
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Fábio Fernandes
- Institute for Bioengineering and Biosciences (IBB) and Associate Laboratory i4HB-Institute for Health and Bioeconomy, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Paulo Rodrigues-Santos
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Trond Aasen
- Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Viktor I Korolchuk
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Teresa Gonçalves
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Ira Milosevic
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
- University of Oxford, Centre for Human Genetics, Nuffield Department of Medicine, Oxford, UK
| | - Nuno Raimundo
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - Henrique Girão
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal.
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal.
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal.
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal.
| |
Collapse
|
9
|
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.
Collapse
|
10
|
Lucaciu SA, Leighton SE, Hauser A, Yee R, Laird DW. Diversity in connexin biology. J Biol Chem 2023; 299:105263. [PMID: 37734551 PMCID: PMC10598745 DOI: 10.1016/j.jbc.2023.105263] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023] Open
Abstract
Over 35 years ago the cell biology community was introduced to connexins as the subunit employed to assemble semicrystalline clusters of intercellular channels that had been well described morphologically as gap junctions. The decade that followed would see knowledge of the unexpectedly large 21-member human connexin family grow to reflect unique and overlapping expression patterns in all organ systems. While connexin biology initially focused on their role in constructing highly regulated intercellular channels, this was destined to change as discoveries revealed that connexin hemichannels at the cell surface had novel roles in many cell types, especially when considering connexin pathologies. Acceptance of connexins as having bifunctional channel properties was initially met with some resistance, which has given way in recent years to the premise that connexins have multifunctional properties. Depending on the connexin isoform and cell of origin, connexins have wide-ranging half-lives that vary from a couple of hours to the life expectancy of the cell. Diversity in connexin channel characteristics and molecular properties were further revealed by X-ray crystallography and single-particle cryo-EM. New avenues have seen connexins or connexin fragments playing roles in cell adhesion, tunneling nanotubes, extracellular vesicles, mitochondrial membranes, transcription regulation, and in other emerging cellular functions. These discoveries were largely linked to Cx43, which is prominent in most human organs. Here, we will review the evolution of knowledge on connexin expression in human adults and more recent evidence linking connexins to a highly diverse array of cellular functions.
Collapse
Affiliation(s)
- Sergiu A Lucaciu
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Stephanie E Leighton
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Alexandra Hauser
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Ryan Yee
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada.
| |
Collapse
|
11
|
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.
Collapse
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.
| |
Collapse
|
12
|
Cristovao B, Rodrigues L, Catarino S, Abreu M, Gonçalves T, Domingues N, Girao H. Cx43-mediated hyphal folding counteracts phagosome integrity loss during fungal infection. Microbiol Spectr 2023; 11:e0123823. [PMID: 37733471 PMCID: PMC10581180 DOI: 10.1128/spectrum.01238-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 07/27/2023] [Indexed: 09/23/2023] Open
Abstract
Phagolysosomes are crucial organelles during the elimination of pathogens by host cells. The maintenance of their membrane integrity is vital during stressful conditions, such as during Candida albicans infection. As the fungal hyphae grow, the phagolysosome membrane expands to ensure that the growing fungus remains entrapped. Additionally, actin structures surrounding the hyphae-containing phagosome were recently described to damage and constrain these pathogens inside the host vacuoles by inducing their folding. However, the molecular mechanism involved in the phagosome membrane adaptation during this extreme expansion process is still unclear. The main goal of this study was to unveil the interplay between phagosomal membrane integrity and folding capacity of C. albicans-infected macrophages. We show that components of the repair machinery are gradually recruited to the expanding phagolysosomal membrane and that their inhibition diminishes macrophage folding capacity. Through an analysis of an RNAseq data set of C. albicans-infected macrophages, we identified Cx43, a gap junction protein, as a putative player involved in the interplay between lysosomal homeostasis and actin-related processes. Our findings further reveal that Cx43 is recruited to expand phagosomes and potentiates the hyphal folding capacity of macrophages, promoting their survival. Additionally, we reveal that Cx43 can act as an anchor for complexes involved in Arp2-mediated actin nucleation during the assembly of actin rings around hyphae-containing phagosomes. Overall, this work brings new insights on the mechanisms by which macrophages cope with C. albicans infection ascribing to Cx43 a new noncanonical regulatory role in phagosome dynamics during pathogen phagocytosis. IMPORTANCE Invasive candidiasis is a life-threatening fungal infection that can become increasingly resistant to treatment. Thus, strategies to improve immune system efficiency, such as the macrophage response during the clearance of the fungal infection, are crucial to ameliorate the current therapies. Engulfed Candida albicans, one of the most common Candida species, is able to quickly transit from yeast-to-hypha form, which can elicit a phagosomal membrane injury and ultimately lead to macrophage death. Here, we extend the understanding of phagosome membrane homeostasis during the hypha expansion and folding process. We found that loss of phagosomal membrane integrity decreases the capacity of macrophages to fold the hyphae. Furthermore, through a bioinformatic analysis, we reveal a new window of opportunities to disclose the mechanisms underlying the hyphal constraining process. We identified Cx43 as a new weapon in the armamentarium to tackle infection by potentiating hyphal folding and promoting macrophage survival.
Collapse
Affiliation(s)
- Beatriz Cristovao
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), Clinical Academic Centre of Coimbra (CACC), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Lisa Rodrigues
- Center for Neurosciences and Cell Biology (CNC-UC), University of Coimbra, Coimbra, Portugal
| | - Steve Catarino
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), Clinical Academic Centre of Coimbra (CACC), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Monica Abreu
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), Clinical Academic Centre of Coimbra (CACC), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Teresa Gonçalves
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
- Center for Neurosciences and Cell Biology (CNC-UC), University of Coimbra, Coimbra, Portugal
| | - Neuza Domingues
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), Clinical Academic Centre of Coimbra (CACC), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Henrique Girao
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), Clinical Academic Centre of Coimbra (CACC), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| |
Collapse
|
13
|
Shimura D, Shaw RM. Live-cell imaging and analysis of actin-mediated mitochondrial fission. STAR Protoc 2023; 4:101958. [PMID: 36542522 PMCID: PMC9795527 DOI: 10.1016/j.xpro.2022.101958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/02/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Current approaches, such as fixed-cell imaging or single-snapshot imaging, are insufficient to capture cytoskeleton-mediated mitochondrial fission. Here, we present a protocol to capture actin-mediated mitochondrial fission using high-resolution time-lapse imaging. We describe steps starting from cell preparation and mitochondria labeling through to live-cell imaging and final analysis. This approach is also applicable for analysis of multiple cytoskeleton-mediated organelle events such as vesicle trafficking, membrane fusion, and endocytic events in live cells. For complete details on the use and execution of this protocol, please refer to Shimura et al. (2021).1.
Collapse
Affiliation(s)
- Daisuke Shimura
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA; Department of Surgery, School of Medicine, University of Utah, Salt Lake City, UT 84112, USA.
| | - Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA.
| |
Collapse
|
14
|
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.
Collapse
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.
| |
Collapse
|
15
|
Whisenant CC, Shaw RM. Internal translation of Gja1 (Connexin43) to produce GJA1-20k: Implications for arrhythmia and ischemic-preconditioning. Front Physiol 2022; 13:1058954. [PMID: 36569758 PMCID: PMC9768480 DOI: 10.3389/fphys.2022.1058954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
Internal translation is a form of post-translation modification as it produces different proteins from one mRNA molecule by beginning translation at a methionine coding triplet downstream of the first methionine. Internal translation can eliminate domains of proteins that otherwise restrict movement or activity, thereby creating profound functional diversity. Connexin43 (Cx43), encoded by the gene Gja1, is the main gap junction protein necessary for propagating action potentials between adjacent cardiomyocytes. Gja1 can be internally translated to produce a peptide 20 kD in length named GJA1-20k. This review focuses on the role of GJA1-20k in maintaining cardiac electrical rhythm as well as in ischemic preconditioning (IPC). Connexin43 is the only ion channel we are aware that has been reported to be subject to internal translation. We expect many other ion channels also undergo internal translation. The exploration of post-translational modification of ion channels, and in particular of internal translation, has the potential to greatly increase our understanding of both canonical and non-canonical ion channel biology.
Collapse
|
16
|
Himelman E, Nouet J, Lillo MA, Chong A, Zhou D, Wehrens XHT, Rodney GG, Xie LH, Shirokova N, Contreras JE, Fraidenraich D. A microtubule-connexin-43 regulatory link suppresses arrhythmias and cardiac fibrosis in Duchenne muscular dystrophy mice. Am J Physiol Heart Circ Physiol 2022; 323:H983-H995. [PMID: 36206047 PMCID: PMC9639757 DOI: 10.1152/ajpheart.00179.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 12/14/2022]
Abstract
Dilated cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD), an inherited degenerative disease of the cardiac and skeletal muscle caused by absence of the protein dystrophin. We showed one hallmark of DMD cardiomyopathy is the dysregulation of cardiac gap junction channel protein connexin-43 (Cx43). Proper Cx43 localization and function at the cardiac intercalated disc (ID) is regulated by post-translational phosphorylation of Cx43-carboxy-terminus residues S325/S328/S330 (pS-Cx43). Concurrently, Cx43 traffics along microtubules (MTs) for targeted delivery to the ID. In DMD hearts, absence of dystrophin results in a hyperdensified and disorganized MT cytoskeleton, yet the link with pS-Cx43 remains unaddressed. To gain insight into the relationship between MTs and pS-Cx43, DMD mice (mdx) and pS-Cx43-deficient (mdxS3A) mice were treated with an inhibitor of MT polymerization, colchicine (Colch). Colch treatment protected mdx, not mdxS3A mice, against Cx43 remodeling, improved MT directionality, and enhanced pS-Cx43/tubulin interaction. Likewise, severe arrhythmias were prevented in isoproterenol-stressed mdx, not mdxS3A mice. Furthermore, MT directionality was improved in pS-Cx43-mimicking mdx (mdxS3E). Mdxutr+/- and mdxutr+/-S3A mice, lacking one copy of dystrophin homolog utrophin, displayed enhanced cardiac fibrosis and reduced lifespan compared with mdxutr+/-S3E; and Colch treatment corrected cardiac fibrosis in mdxutr+/- but not mdxutr+/-S3A. Collectively, the data suggest that improved MT directionality reduces Cx43 remodeling and that pS-Cx43 is necessary and sufficient to regulate MT organization, which plays crucial role in correcting cardiac dysfunction in DMD mice. Thus, identification of novel organizational mechanisms acting on pS-Cx43-MT will help develop novel cardioprotective therapies for DMD cardiomyopathy.NEW & NOTEWORTHY We found that colchicine administration to Cx43-phospho-deficient dystrophic mice fails to protect against Cx43 remodeling. Conversely, Cx43-phospho-mimic dystrophic mice display a normalized MT network. We envision a bidirectional regulation whereby correction of the dystrophic MTs leads to correction of Cx43 remodeling, which in turn leads to further correction of the MTs. Our findings suggest a link between phospho-Cx43 and MTs that provides strong foundations for novel therapeutics in DMD cardiomyopathy.
Collapse
Affiliation(s)
- Eric Himelman
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Julie Nouet
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Mauricio A Lillo
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Alexander Chong
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Delong Zhou
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Xander H T Wehrens
- Department of Molecular Physiology and Biophysics, Medicine, Neuroscience, and Pediatrics, Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas
| | - George G Rodney
- Department of Molecular Physiology and Biophysics, Medicine, Neuroscience, and Pediatrics, Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Natalia Shirokova
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Jorge E Contreras
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Diego Fraidenraich
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| |
Collapse
|
17
|
Jones JC, Bodenstine TM. Connexins and Glucose Metabolism in Cancer. Int J Mol Sci 2022; 23:ijms231710172. [PMID: 36077565 PMCID: PMC9455984 DOI: 10.3390/ijms231710172] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Connexins are a family of transmembrane proteins that regulate diverse cellular functions. Originally characterized for their ability to mediate direct intercellular communication through the formation of highly regulated membrane channels, their functions have been extended to the exchange of molecules with the extracellular environment, and the ability to modulate numerous channel-independent effects on processes such as motility and survival. Notably, connexins have been implicated in cancer biology for their context-dependent roles that can both promote or suppress cancer cell function. Moreover, connexins are able to mediate many aspects of cellular metabolism including the intercellular coupling of nutrients and signaling molecules. During cancer progression, changes to substrate utilization occur to support energy production and biomass accumulation. This results in metabolic plasticity that promotes cell survival and proliferation, and can impact therapeutic resistance. Significant progress has been made in our understanding of connexin and cancer biology, however, delineating the roles these multi-faceted proteins play in metabolic adaptation of cancer cells is just beginning. Glucose represents a major carbon substrate for energy production, nucleotide synthesis, carbohydrate modifications and generation of biosynthetic intermediates. While cancer cells often exhibit a dependence on glycolytic metabolism for survival, cellular reprogramming of metabolic pathways is common when blood perfusion is limited in growing tumors. These metabolic changes drive aggressive phenotypes through the acquisition of functional traits. Connections between glucose metabolism and connexin function in cancer cells and the surrounding stroma are now apparent, however much remains to be discovered regarding these relationships. This review discusses the existing evidence in this area and highlights directions for continued investigation.
Collapse
|
18
|
Jang DG, Kwon KY, Kweon YC, Kim BG, Myung K, Lee HS, Young Park C, Kwon T, Park TJ. GJA1 depletion causes ciliary defects by affecting Rab11 trafficking to the ciliary base. eLife 2022; 11:81016. [PMID: 36004726 PMCID: PMC9448326 DOI: 10.7554/elife.81016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/11/2022] [Indexed: 11/13/2022] Open
Abstract
The gap junction complex functions as a transport channel across the membrane. Among gap junction subunits, gap junction protein α1 (GJA1) is the most commonly expressed subunit. A recent study showed that GJA1 is necessary for the maintenance of motile cilia; however, the molecular mechanism and function of GJA1 in ciliogenesis remain unknown. Here, we examined the functions of GJA1 during ciliogenesis in human retinal pigment epithelium-1 and Xenopus laevis embryonic multiciliated-cells. GJA1 localizes to the motile ciliary axonemes or pericentriolar regions beneath the primary cilium. GJA1 depletion caused malformation of both the primary cilium and motile cilia. Further study revealed that GJA1 depletion affected several ciliary proteins such as BBS4, CP110, and Rab11 in the pericentriolar region and basal body. Interestingly, CP110 removal from the mother centriole was significantly reduced by GJA1 depletion. Importantly, Rab11, a key regulator during ciliogenesis, was immunoprecipitated with GJA1, and GJA1 knockdown caused the mislocalization of Rab11. These findings suggest that GJA1 regulates ciliogenesis by interacting with the Rab11-Rab8 ciliary trafficking pathway.
Collapse
Affiliation(s)
- Dong Gil Jang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Keun Yeong Kwon
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Yeong Cheon Kweon
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Byung-Gyu Kim
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, Republic of Korea
| | - Kyungjae Myung
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, Republic of Korea
| | - Hyun-Shik Lee
- School of Life Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Chan Young Park
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Taejoon Kwon
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Tae Joo Park
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| |
Collapse
|
19
|
Hamledari H, Asghari P, Jayousi F, Aguirre A, Maaref Y, Barszczewski T, Ser T, Moore E, Wasserman W, Klein Geltink R, Teves S, Tibbits GF. Using human induced pluripotent stem cell-derived cardiomyocytes to understand the mechanisms driving cardiomyocyte maturation. Front Cardiovasc Med 2022; 9:967659. [PMID: 36061558 PMCID: PMC9429949 DOI: 10.3389/fcvm.2022.967659] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/28/2022] [Indexed: 11/13/2022] Open
Abstract
Cardiovascular diseases are the leading cause of mortality and reduced quality of life globally. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) provide a personalized platform to study inherited heart diseases, drug-induced cardiac toxicity, and cardiac regenerative therapy. However, the immaturity of CMs obtained by current strategies is a major hurdle in utilizing hiPSC-CMs at their fullest potential. Here, the major findings and limitations of current maturation methodologies to enhance the utility of hiPSC-CMs in the battle against a major source of morbidity and mortality are reviewed. The most recent knowledge of the potential signaling pathways involved in the transition of fetal to adult CMs are assimilated. In particular, we take a deeper look on role of nutrient sensing signaling pathways and the potential role of cap-independent translation mediated by the modulation of mTOR pathway in the regulation of cardiac gap junctions and other yet to be identified aspects of CM maturation. Moreover, a relatively unexplored perspective on how our knowledge on the effects of preterm birth on cardiovascular development can be actually utilized to enhance the current understanding of CM maturation is examined. Furthermore, the interaction between the evolving neonatal human heart and brown adipose tissue as the major source of neonatal thermogenesis and its endocrine function on CM development is another discussed topic which is worthy of future investigation. Finally, the current knowledge regarding transcriptional mediators of CM maturation is still limited. The recent studies have produced the groundwork to better understand CM maturation in terms of providing some of the key factors involved in maturation and development of metrics for assessment of maturation which proves essential for future studies on in vitro PSC-CMs maturation.
Collapse
Affiliation(s)
- Homa Hamledari
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Parisa Asghari
- Department of Cellular and Physiological Sciences, University of British Colombia, Vancouver, BC, Canada
| | - Farah Jayousi
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Alejandro Aguirre
- Department of Medical Genetics, University of British Colombia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Yasaman Maaref
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Tiffany Barszczewski
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Terri Ser
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, University of British Colombia, Vancouver, BC, Canada
| | - Edwin Moore
- Department of Cellular and Physiological Sciences, University of British Colombia, Vancouver, BC, Canada
| | - Wyeth Wasserman
- Department of Medical Genetics, University of British Colombia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Ramon Klein Geltink
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, University of British Colombia, Vancouver, BC, Canada
| | - Sheila Teves
- Department of Biochemistry and Molecular Biology, University of British Colombia, Vancouver, BC, Canada
| | - Glen F. Tibbits
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
20
|
Ren D, Zheng P, Zou S, Gong Y, Wang Y, Duan J, Deng J, Chen H, Feng J, Zhong C, Chen W. GJA1-20K Enhances Mitochondria Transfer from Astrocytes to Neurons via Cx43-TnTs After Traumatic Brain Injury. Cell Mol Neurobiol 2022; 42:1887-1895. [PMID: 33728536 PMCID: PMC11421752 DOI: 10.1007/s10571-021-01070-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 02/23/2021] [Indexed: 12/30/2022]
Abstract
Astrocytes are crucial in neural protection after traumatic brain injury (TBI), a global health problem causing severe brain tissue damage. Astrocytic connexin 43 (Cx43), encoded by GJA1 gene, has been demonstrated to facilitate the protection of astrocytes to neural damage with unclear mechanisms. This study aims to explore the role of GJA1-20K/Cx43 axis in the astrocyte-neuron interaction after TBI and the underlying mechanisms. Primarily cultured cortical neurons isolated from embryonic C57BL/6 mice were treated by compressed nitrogen-oxygen mixed gas to simulate TBI-like damage in vitro. The transwell astrocyte-neuron co-culture system were constructed to recapitulate the interaction between the two cell types. Quantitative PCR was applied to analyze mRNA level of target genes. Western blot and immunofluorescence were conducted to detect target proteins expression. GJA1-20K overexpression significantly down-regulated the expression of phosphorylated Cx43 (p-Cx43) without affecting the total Cx43 protein level. Besides, GJA1-20K overexpression obviously enhanced the dendrite length, as well as the expression levels of function and synthesis-related factors of mitochondria in damaged neurons. GJA1-20K up-regulated functional Cx43 expression in astrocytes, which promoted mitochondria transmission from astrocytes to neurons which might be responsible to the protection of astrocyte to neurons after TBI-like damage in vitro.
Collapse
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, 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, China
| | - Shufeng Zou
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, NanchangJiangxi, 330008, China
| | - Yuqin Gong
- Department of Operation Room, The Second Affiliated Hospital of Nanchang University, NanchangJiangxi, 330009, China
| | - Yang Wang
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, NanchangJiangxi, 330008, China
| | - Jian Duan
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, NanchangJiangxi, 330008, China
| | - Jun Deng
- Department of Emergency@Trauma Center, The First Affiliated Hospital of Nanchang University, Nanchang, 330008, Jiangxi, China
| | - Haiming Chen
- Department of Emergency@Trauma Center, The First Affiliated Hospital of Nanchang University, Nanchang, 330008, Jiangxi, China
| | - Jiugeng Feng
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, NanchangJiangxi, 330008, China.
| | - Chunlong Zhong
- Department of Neurosurgery, Shanghai East Hospital, Tongji University, Shanghai, 201200, 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, China.
- Department of Neurosurgery, Shanghai East Hospital, Tongji University, Shanghai, 201200, China.
| |
Collapse
|
21
|
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: 28] [Impact Index Per Article: 9.3] [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.
Collapse
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,
| |
Collapse
|
22
|
He D, Ma Z, Xue K, Li H. Juxtamembrane 2 mimic peptide competitively inhibits mitochondrial trafficking and activates ROS-mediated apoptosis pathway to exert anti-tumor effects. Cell Death Dis 2022; 13:264. [PMID: 35332127 PMCID: PMC8948362 DOI: 10.1038/s41419-022-04639-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 01/25/2022] [Accepted: 02/09/2022] [Indexed: 11/26/2022]
Abstract
Our previous study demonstrates that a juxtamembrane 2 (JM2) mimic peptide can inhibit proliferation and induce apoptosis of tumor cells. However, the mechanism remains unclear. In this study, JM2 is found to suppress the growth of 4T1 breast tumors by inducing apoptosis and inhibiting the proliferation of 4T1 tumor cells. Further study indicates that JM2 can stimulate the mitochondria to gather near the microtubule-organizing center of tumor cells and subsequently induce ROS-induced ROS release responses, which results in mitochondrial dysfunction and mitochondria-mediated apoptosis. In addition, JM2 can arrest cell cycle in S phase by regulating the expression of cell cycle-related proteins and consequently inhibit proliferation of tumor cells. Then, a previously designed JM2 grafted hyaluronic acid (HA) injectable hydrogel system (HA-JM2) is injected in a breast tumor-resected model and the HA-JM2 hydrogel can inhibit the malignant proliferation of residual tumor cells and suppress the breast tumor recurrence. These findings not only confirm the application potentials of JM2 in anti-tumor therapy and tumor post-surgery treatments but also provide greater understanding on the mechanisms by which JM2 inhibits tumor growth.
Collapse
Affiliation(s)
- Dan He
- School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China
| | - Zhijie Ma
- School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China
| | - Ke Xue
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Rd, Shanghai, 200011, China.
| | - Haiyan Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China.
- Chemical and Environmental Engineering, School of Engineering, RMIT University, 124 La Trobe Stø, Melbourne, VIC, 3000, Australia.
| |
Collapse
|
23
|
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: 0.3] [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.
Collapse
|
24
|
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: 12] [Impact Index Per Article: 4.0] [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.
Collapse
|
25
|
García-Niño WR, Zazueta C, Buelna-Chontal M, Silva-Palacios A. Mitochondrial Quality Control in Cardiac-Conditioning Strategies against Ischemia-Reperfusion Injury. Life (Basel) 2021; 11:1123. [PMID: 34832998 PMCID: PMC8620839 DOI: 10.3390/life11111123] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are the central target of ischemic preconditioning and postconditioning cardioprotective strategies, which consist of either the application of brief intermittent ischemia/reperfusion (I/R) cycles or the administration of pharmacological agents. Such strategies reduce cardiac I/R injury by activating protective signaling pathways that prevent the exacerbated production of reactive oxygen/nitrogen species, inhibit opening of mitochondrial permeability transition pore and reduce apoptosis, maintaining normal mitochondrial function. Cardioprotection also involves the activation of mitochondrial quality control (MQC) processes, which replace defective mitochondria or eliminate mitochondrial debris, preserving the structure and function of the network of these organelles, and consequently ensuring homeostasis and survival of cardiomyocytes. Such processes include mitochondrial biogenesis, fission, fusion, mitophagy and mitochondrial-controlled cell death. This review updates recent advances in MQC mechanisms that are activated in the protection conferred by different cardiac conditioning interventions. Furthermore, the role of extracellular vesicles in mitochondrial protection and turnover of these organelles will be discussed. It is concluded that modulation of MQC mechanisms and recognition of mitochondrial targets could provide a potential and selective therapeutic approach for I/R-induced mitochondrial dysfunction.
Collapse
|
26
|
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: 23] [Impact Index Per Article: 5.8] [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.
Collapse
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
| |
Collapse
|
27
|
Kléber AG, Jin Q. Coupling between cardiac cells-An important determinant of electrical impulse propagation and arrhythmogenesis. ACTA ACUST UNITED AC 2021; 2:031301. [PMID: 34296210 DOI: 10.1063/5.0050192] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/09/2021] [Indexed: 01/30/2023]
Abstract
Cardiac arrhythmias are an important cause of sudden cardiac death-a devastating manifestation of many underlying causes, such as heart failure and ischemic heart disease leading to ventricular tachyarrhythmias and ventricular fibrillation, and atrial fibrillation causing cerebral embolism. Cardiac electrical propagation is a main factor in the initiation and maintenance of cardiac arrhythmias. In the heart, gap junctions are the basic unit at the cellular level that host intercellular low-resistance channels for the diffusion of ions and small regulatory molecules. The dual voltage clamp technique enabled the direct measurement of electrical conductance between cells and recording of single gap junction channel openings. The rapid turnover of gap junction channels at the intercalated disk implicates a highly dynamic process of trafficking and internalization of gap junction connexons. Recently, non-canonical roles of gap junction proteins have been discovered in mitochondria function, cytoskeletal organization, trafficking, and cardiac rescue. At the tissue level, we explain the concepts of linear propagation and safety factor based on the model of linear cellular structure. Working myocardium is adequately represented as a discontinuous cellular network characterized by cellular anisotropy and connective tissue heterogeneity. Electrical propagation in discontinuous cellular networks reflects an interplay of three main factors: cell-to-cell electrical coupling, flow of electrical charge through the ion channels, and the microscopic tissue structure. This review provides a state-of-the-art update of the cardiac gap junction channels and their role in cardiac electrical impulse propagation and highlights a combined approach of genetics, cell biology, and physics in modern cardiac electrophysiology.
Collapse
Affiliation(s)
- André G Kléber
- Department of Pathology, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Qianru Jin
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, Massachusetts 02134, USA
| |
Collapse
|
28
|
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: 69] [Impact Index Per Article: 17.3] [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.
Collapse
|
29
|
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: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 06/07/2020] [Indexed: 02/06/2023]
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.
Collapse
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.
| |
Collapse
|
30
|
Garbern JC, Lee RT. Mitochondria and metabolic transitions in cardiomyocytes: lessons from development for stem cell-derived cardiomyocytes. Stem Cell Res Ther 2021; 12:177. [PMID: 33712058 PMCID: PMC7953594 DOI: 10.1186/s13287-021-02252-6] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/28/2021] [Indexed: 12/13/2022] Open
Abstract
Current methods to differentiate cardiomyocytes from human pluripotent stem cells (PSCs) inadequately recapitulate complete development and result in PSC-derived cardiomyocytes (PSC-CMs) with an immature or fetal-like phenotype. Embryonic and fetal development are highly dynamic periods during which the developing embryo or fetus is exposed to changing nutrient, oxygen, and hormone levels until birth. It is becoming increasingly apparent that these metabolic changes initiate developmental processes to mature cardiomyocytes. Mitochondria are central to these changes, responding to these metabolic changes and transitioning from small, fragmented mitochondria to large organelles capable of producing enough ATP to support the contractile function of the heart. These changes in mitochondria may not simply be a response to cardiomyocyte maturation; the metabolic signals that occur throughout development may actually be central to the maturation process in cardiomyocytes. Here, we review methods to enhance maturation of PSC-CMs and highlight evidence from development indicating the key roles that mitochondria play during cardiomyocyte maturation. We evaluate metabolic transitions that occur during development and how these affect molecular nutrient sensors, discuss how regulation of nutrient sensing pathways affect mitochondrial dynamics and function, and explore how changes in mitochondrial function can affect metabolite production, the cell cycle, and epigenetics to influence maturation of cardiomyocytes.
Collapse
Affiliation(s)
- Jessica C Garbern
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, 7 Divinity Ave, Cambridge, MA, 02138, USA
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Richard T Lee
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, 7 Divinity Ave, Cambridge, MA, 02138, USA.
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 75 Francis St, Boston, MA, 02115, USA.
| |
Collapse
|
31
|
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: 43] [Impact Index Per Article: 10.8] [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.
Collapse
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
| |
Collapse
|
32
|
Shaw RM, Saffitz JE. A role for connexin-43 in Duchenne muscular dystrophy cardiomyopathy. J Clin Invest 2020; 130:1608-1610. [PMID: 32091412 DOI: 10.1172/jci135007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The cardiomyopathy of Duchenne muscular dystrophy (DMD) is an important cause of morbidity and mortality in affected males with this dreaded muscle disease. Previous studies have implicated changes in expression and subcellular localization of connexin-43 (Cx43), the major ventricular gap junction protein, in DMD cardiomyopathy. In this issue of the JCI, Himelman et al. explore how hypophosphorylation of Cx43 at a triplet of serine residues (S325/S328/S330) in the regulatory C-terminus contributes to multiple features of the cardiomyopathy phenotype. Using a mouse model of DMD cardiomyopathy in which phosphomimetic glutamic acids are substituted for serines at these residues in Cx43, Himelman et al. observed reduced gap junction remodeling and lateralization of Cx43 immunosignals, protection against isoproterenol-induced arrhythmias, and improved Ca2+ homeostasis. This study contributes to the understanding of pathologic Cx43 remodeling and encourages further research into developing strategic interventions to mitigate cardiac dysfunction and arrhythmias in DMD patients.
Collapse
Affiliation(s)
- Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA
| | - Jeffrey E Saffitz
- Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| |
Collapse
|
33
|
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: 46] [Impact Index Per Article: 9.2] [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.
Collapse
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
| |
Collapse
|
34
|
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: 21] [Impact Index Per Article: 4.2] [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.
Collapse
|
35
|
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.
Collapse
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
| |
Collapse
|
36
|
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: 6.4] [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.
Collapse
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
| |
Collapse
|
37
|
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: 13] [Impact Index Per Article: 2.6] [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.
Collapse
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
| |
Collapse
|
38
|
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: 26] [Impact Index Per Article: 5.2] [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.
Collapse
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
| |
Collapse
|
39
|
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: 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: 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.
Collapse
|
40
|
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: 48] [Impact Index Per Article: 9.6] [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
| |
Collapse
|
41
|
Wang M, Smith K, Yu Q, Miller C, Singh K, Sen CK. Mitochondrial connexin 43 in sex-dependent myocardial responses and estrogen-mediated cardiac protection following acute ischemia/reperfusion injury. Basic Res Cardiol 2019; 115:1. [PMID: 31741053 DOI: 10.1007/s00395-019-0759-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/05/2019] [Indexed: 01/23/2023]
Abstract
Preserving mitochondrial activity is crucial in rescuing cardiac function following acute myocardial ischemia/reperfusion (I/R). The sex difference in myocardial functional recovery has been observed after I/R. Given the key role of mitochondrial connexin43 (Cx43) in cardiac protection initiated by ischemic preconditioning, we aimed to determine the implication of mitochondrial Cx43 in sex-related myocardial responses and to examine the effect of estrogen (17β-estradiol, E2) on Cx43, particularly mitochondrial Cx43-involved cardiac protection following I/R. Mouse primary cardiomyocytes and isolated mouse hearts (from males, females, ovariectomized females, and doxycycline-inducible Tnnt2-controlled Cx43 knockout without or with acute post-ischemic E2 treatment) were subjected to simulated I/R in culture or Langendorff I/R (25-min warm ischemia/40-min reperfusion), respectively. Mitochondrial membrane potential and mitochondrial superoxide production were measured in cardiomyocytes. Myocardial function and infarct size were determined. Cx43 and its isoform, Gja1-20k, were assessed in mitochondria. Immunoelectron microscopy and co-immunoprecipitation were also used to examine mitochondrial Cx43 and its interaction with estrogen receptor-α by E2 in mitochondria, respectively. There were sex disparities in stress-induced cardiomyocyte mitochondrial function. E2 partially restored mitochondrial activity in cardiomyocytes following acute injury. Post-ischemia infusion of E2 improved functional recovery and reduced infarct size with increased Cx43 content and phosphorylation in mitochondria. Ablation of cardiac Cx43 aggravated mitochondrial damage and abolished E2-mediated cardiac protection during I/R. Female mice were more resistant to myocardial I/R than age-matched males with greater protective role of mitochondrial Cx43 in female hearts. Post-ischemic E2 usage augmented mitochondrial Cx43 content and phosphorylation, increased mitochondrial Gja1-20k, and showed cardiac protection.
Collapse
Affiliation(s)
- Meijing Wang
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA.
| | - Kwynlyn Smith
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA
| | - Qing Yu
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA
| | - Caroline Miller
- Electron Microscopy Center, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kanhaiya Singh
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA.,Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chandan K Sen
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA.,Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, USA
| |
Collapse
|
42
|
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: 26] [Impact Index Per Article: 4.3] [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.
Collapse
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
| |
Collapse
|
43
|
Tao S, Jia M, Qiu T. Expression and role of CaMKII and Cx43 in a rat model of post-stroke depression. Exp Ther Med 2019; 18:2153-2159. [PMID: 31410169 PMCID: PMC6676183 DOI: 10.3892/etm.2019.7782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 06/07/2019] [Indexed: 12/16/2022] Open
Abstract
Expression of Ca2+/CaM-dependent protein kinase II (CaMKII) and connexin 43 (Cx43) in a rat model of post-stroke depression (PSD) was investigated. Rats were separated into control group (10 rats underwent a sham operation and were not ligated after incision), PSD group (13 PSD rats) and KN93 group (12 rats were treated with KN93, an inhibitor of CaMKII, on the basis of the PSD group). After PSD modeling, Longa scoring was performed, and an open field test as well as a step-through test were carried out to observe rat behavior. RT-qPCR and western blot analysis were used to detect the expression of CaMKII and CX43 in the hippocampus tissue. On the 14th day, the Longa scores in the PSD and KN93 groups were higher than that in the control group (P<0.05), while on the 18th day, Longa score was higher in the PSD group than that in the control and KN93 groups, and higher in the KN93 group than that in the control group (both P<0.05). In the PSD group, the Longa score on the 18th day was significantly higher than that on the 14th day, whereas in the KN93 group, the Longa score on the 18th day was significantly lower than that on the 14th day (both P<0.05). Compared with the PSD group on the 18th day, the passive avoidance defects in the KN93 group were improved, and the frequency of activity in the open field test was significantly increased. On the 18th day, the expression levels of the mRNA and protein of CaMKII were higher in the PSD group than in the control group, whereas those of Cx43 were lower in the PSD group than those in the control group (P<0.05). The mRNA and protein expression levels of CaMKII in the KN93 group were lower than those in the PSD group, but higher than those in the control group. In PSD rats, CaMKII expression is upregulated, but Cx43 expression is downregulated, and both CaMKII and Cx43 may participate in PSD. The inhibitor of CaMKII, KN93, can improve the depression in PSD rats.
Collapse
Affiliation(s)
- Shuiliang Tao
- College of Basic Medicine, Zhengjiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Mengmeng Jia
- Department of Neurology, Wenzhou Seventh People's Hospital, Wenzhou, Zhejiang 325005, P.R. China
| | - Tao Qiu
- Department of Neurology, Zhejiang Provincial Hospital of TCM, Hangzhou, Zhejiang 310006, P.R. China
| |
Collapse
|
44
|
Jiang J, Hoagland D, Palatinus JA, He H, Iyyathurai J, Jourdan LJ, Bultynck G, Wang Z, Zhang Z, Schey K, Poelzing S, McGowan FX, Gourdie RG. Interaction of α Carboxyl Terminus 1 Peptide With the Connexin 43 Carboxyl Terminus Preserves Left Ventricular Function After Ischemia-Reperfusion Injury. J Am Heart Assoc 2019; 8:e012385. [PMID: 31422747 PMCID: PMC6759879 DOI: 10.1161/jaha.119.012385] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Background α Carboxyl terminus 1 (αCT1) is a 25–amino acid therapeutic peptide incorporating the zonula occludens‐1 (ZO‐1)–binding domain of connexin 43 (Cx43) that is currently in phase 3 clinical testing on chronic wounds. In mice, we reported that αCT1 reduced arrhythmias after cardiac injury, accompanied by increases in protein kinase Cε phosphorylation of Cx43 at serine 368. Herein, we characterize detailed molecular mode of action of αCT1 in mitigating cardiac ischemia‐reperfusion injury. Methods and Results To study αCT1‐mediated increases in phosphorylation of Cx43 at serine 368, we undertook mass spectrometry of protein kinase Cε phosphorylation assay reactants. This indicated potential interaction between negatively charged residues in the αCT1 Asp‐Asp‐Leu‐Glu‐Iso sequence and lysines (Lys345, Lys346) in an α‐helical sequence (helix 2) within the Cx43‐CT. In silico modeling provided further support for this interaction, indicating that αCT1 may interact with both Cx43 and ZO‐1. Using surface plasmon resonance, thermal shift, and phosphorylation assays, we characterized a series of αCT1 variants, identifying peptides that interacted with either ZO‐1–postsynaptic density‐95/disks large/zonula occludens‐1 2 or Cx43‐CT, but with limited or no ability to bind both molecules. Only peptides competent to interact with Cx43‐CT, but not ZO‐1–postsynaptic density‐95/disks large/zonula occludens‐1 2 alone, prompted increased pS368 phosphorylation. Moreover, in an ex vivo mouse model of ischemia‐reperfusion injury, preischemic infusion only with those peptides competent to bind Cx43 preserved ventricular function after ischemia‐reperfusion. Interestingly, a short 9–amino acid variant of αCT1 (αCT11) demonstrated potent cardioprotective effects when infused either before or after ischemic injury. Conclusions Interaction of αCT1 with the Cx43, but not ZO‐1, is correlated with cardioprotection. Pharmacophores targeting Cx43‐CT could provide a translational approach to preserving heart function after ischemic injury.
Collapse
Affiliation(s)
- Jingbo Jiang
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA.,Shenzhen Children's Hospital Shenzhen China.,Department of Pediatric Cardiology Guangdong Cardiovascular Institute Guangdong General Hospital Guangdong Academy of Medical Sciences Guangzhou China
| | - Daniel Hoagland
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA
| | - Joseph A Palatinus
- Cedars-Sinai Heart Smidt Institute Cedars-Sinai Medical Center Los Angeles CA
| | - Huamei He
- Department of Anesthesiology and Critical Care Medicine Children's Hospital of Philadelphia and University of Pennsylvania Philadelphia PA
| | - Jegan Iyyathurai
- Department Cellular and Molecular Medicine KU Leuven Laboratory of Molecular and Cellular Signaling Leuven Belgium
| | - L Jane Jourdan
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA
| | - Geert Bultynck
- Department Cellular and Molecular Medicine KU Leuven Laboratory of Molecular and Cellular Signaling Leuven Belgium
| | - Zhen Wang
- Department of Biochemistry Vanderbilt University School of Medicine Nashville TN
| | - Zhiwei Zhang
- Department of Pediatric Cardiology Guangdong Cardiovascular Institute Guangdong General Hospital Guangdong Academy of Medical Sciences Guangzhou China
| | - Kevin Schey
- Department of Biochemistry Vanderbilt University School of Medicine Nashville TN
| | - Steven Poelzing
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA.,Department of Biomedical Engineering and Mechanics Virginia Tech Blacksburg VA
| | - Francis X McGowan
- Department of Anesthesiology and Critical Care Medicine Children's Hospital of Philadelphia and University of Pennsylvania Philadelphia PA
| | - Robert G Gourdie
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA.,Department of Biomedical Engineering and Mechanics Virginia Tech Blacksburg VA
| |
Collapse
|
45
|
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: 63] [Impact Index Per Article: 10.5] [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.
Collapse
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.
| |
Collapse
|
46
|
Grimes KM, Prasad V, McNamara JW. Supporting the heart: Functions of the cardiomyocyte's non-sarcomeric cytoskeleton. J Mol Cell Cardiol 2019; 131:187-196. [PMID: 30978342 DOI: 10.1016/j.yjmcc.2019.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 04/02/2019] [Accepted: 04/05/2019] [Indexed: 02/06/2023]
Abstract
The non-contractile cytoskeleton in cardiomyocytes is comprised of cytoplasmic actin, microtubules, and intermediate filaments. In addition to providing mechanical support to these cells, these structures are important effectors of tension-sensing and signal transduction and also provide networks for the transport of proteins and organelles. The majority of our knowledge on the function and structure of these cytoskeletal networks comes from research on proliferative cell types. However, in recent years, researchers have begun to show that there are important cardiomyocyte-specific functions of the cytoskeleton. Here we will discuss the current state of cytoskeletal biology in cardiomyocytes, as well as research from other cell types, that together suggest there is a wealth of knowledge on cardiac health and disease waiting to be uncovered through exploration of the complex signaling networks of cardiomyocyte non-sarcomeric cytoskeletal proteins.
Collapse
Affiliation(s)
- Kelly M Grimes
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
| | - Vikram Prasad
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - James W McNamara
- Heart, Lung and Vascular Institute, University of Cincinnati, Cincinnati, OH, USA
| |
Collapse
|
47
|
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: 3.0] [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.
Collapse
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.
| |
Collapse
|
48
|
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: 22] [Impact Index Per Article: 3.7] [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.
Collapse
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
| |
Collapse
|
49
|
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: 9] [Impact Index Per Article: 1.5] [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.
Collapse
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.
| |
Collapse
|
50
|
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: 3.5] [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.
Collapse
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
| |
Collapse
|