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Ugur D, Gungul TB, Yucel S, Ozcivici E, Yalcin-Ozuysal O, Mese G. Connexin 32 overexpression increases proliferation, reduces gap junctional intercellular communication, motility and epithelial-to-mesenchymal transition in Hs578T breast cancer cells. J Cell Commun Signal 2022; 16:361-376. [PMID: 35781670 DOI: 10.1007/s12079-021-00665-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 12/14/2021] [Indexed: 11/29/2022] Open
Abstract
Connexins (Cx) are primary components of gap junctions that selectively allow molecules to be exchanged between adjacent cells, regulating multiple cellular functions. Along with their channel forming functions, connexins play a variety of roles in different stages of tumorigenesis and their roles in tumor initiation and progression is isoform- and tissue-specific. While Cx26 and Cx43 were downregulated during breast tumorigenesis, Cx32 was accumulated in the cytoplasm of the cells in lymph node metastasis of breast cancers and Cx32 was further upregulated in metastasis. Cx32's effect on cell proliferation, gap junctional communication, hemichannel activity, cellular motility and epithelial-to-mesenchymal transition (EMT) were investigated by overexpressing Cx32 in Hs578T and MCF7 breast cancer cells. Additionally, the expression and localization of Cx26 and Cx43 upon Cx32 overexpression were examined by Western blot and immunostaining experiments, respectively. We observed that MCF7 cells had endogenous Cx32 while Hs578T cells did not and when Cx32 was overexpressed in these cells, it caused a significant increase in the percentages of Hs578T cells at the S phase in addition to increasing their proliferation. Further, while Cx32 overexpression did not induce hemichannel activity in either cell, it decreased gap junctional communication between Hs578T cells. Additionally, Cx32 was mainly observed in the cytoplasm in both cells, where it did not form gap junction plaques but Cx32 overexpression reduced Cx43 levels without affecting Cx26. Moreover, migration and invasion potentials of Hs578T and migration in MCF7 were reduced upon Cx32 overexpression. Finally, the protein level of mesenchymal marker N-cadherin decreased while epithelial marker ZO-1 and E-cadherin increased in Hs578T cells. We observed that Cx32 overexpression altered cell proliferation, communication, migration and EMT in Hs578T, suggesting a tumor suppressor role in these cells while it had minor effects on MCF7 cells.
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Affiliation(s)
- Deniz Ugur
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, Izmir, 35430, Turkey.,Department of Molecular Biology and Genetics, Avrasya University, Trabzon, Turkey
| | - Taha Bugra Gungul
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, Izmir, 35430, Turkey
| | - Simge Yucel
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, Izmir, 35430, Turkey
| | - Engin Ozcivici
- Department of Bioengineering, Izmir Institute of Technology, Urla, Izmir, Turkey
| | - Ozden Yalcin-Ozuysal
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, Izmir, 35430, Turkey
| | - Gulistan Mese
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, Izmir, 35430, Turkey.
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2
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Sargiannidou I, Christophidou-Anastasiadou V, Hadjisavvas A, Tanteles GA, Kleopa KA. Novel GJA1/Cx43 Variant Associated With Oculo-Dento-Digital Dysplasia Syndrome: Clinical Phenotype and Cellular Mechanisms. Front Genet 2021; 11:604806. [PMID: 33584802 PMCID: PMC7873484 DOI: 10.3389/fgene.2020.604806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/21/2020] [Indexed: 11/13/2022] Open
Abstract
Oculodentodigital dysplasia syndrome is associated with numerous pathogenic variants in GJA1, the gene encoding connexin43 gap junction protein. A novel in-frame deletion (p.Lys134del) was found in our clinic. The patient showed all the typical dysmorphic features of the syndrome. The functional consequences of this variant were also studied in an in vitro system. Cells expressed significantly less number of gap junction plaques with a great number of them retained intracellularly.
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Affiliation(s)
- Irene Sargiannidou
- Department of Neuroscience, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Violetta Christophidou-Anastasiadou
- Clinical Genetics Center, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.,Department of Clinical Genetics, Makarios Hospital, Nicosia, Cyprus
| | - Andreas Hadjisavvas
- Department of Molecular Pathology and Electron Microscopy, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - George A Tanteles
- Clinical Genetics Center, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Kleopas A Kleopa
- Department of Neuroscience, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.,Center of Neuromuscular Disorders, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.,Center for Multiple Sclerosis and Related Disorders, Cyprus School of Molecular Medicine, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
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3
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Okada M, Fukuyama K, Shiroyama T, Murata M. A Working Hypothesis Regarding Identical Pathomechanisms between Clinical Efficacy and Adverse Reaction of Clozapine via the Activation of Connexin43. Int J Mol Sci 2020; 21:ijms21197019. [PMID: 32987640 PMCID: PMC7583770 DOI: 10.3390/ijms21197019] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/04/2020] [Accepted: 09/22/2020] [Indexed: 12/11/2022] Open
Abstract
Clozapine (CLZ) is an approved antipsychotic agent for the medication of treatment-resistant schizophrenia but is also well known as one of the most toxic antipsychotics. Recently, the World Health Organization’s (WHO) global database (VigiBase) reported the relative lethality of severe adverse reactions of CLZ. Agranulocytosis is the most famous adverse CLZ reaction but is of lesser lethality compared with the other adverse drug reactions of CLZ. Unexpectedly, VigiBase indicated that the prevalence and relative lethality of pneumonia, cardiotoxicity, and seizures associated with CLZ were more serious than that of agranulocytosis. Therefore, haematological monitoring in CLZ patients monitoring system provided success in the prevention of lethal adverse events from CLZ-induced agranulocytosis. Hereafter, psychiatrists must amend the CLZ patients monitoring system to protect patients with treatment-resistant schizophrenia from severe adverse CLZ reactions, such as pneumonia, cardiotoxicity, and seizures, according to the clinical evidence and pathophysiology. In this review, we discuss the mechanisms of clinical efficacy and the adverse reactions of CLZ based on the accumulating pharmacodynamic findings of CLZ, including tripartite synaptic transmission, and we propose suggestions for amending the monitoring and medication of adverse CLZ reactions associated with pneumonia, cardiotoxicity, and seizures.
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Affiliation(s)
- Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan; (K.F.); (T.S.)
- Correspondence: ; Tel.: +81-59-231-5018
| | - Kouji Fukuyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan; (K.F.); (T.S.)
| | - Takashi Shiroyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan; (K.F.); (T.S.)
| | - Masahiko Murata
- National Hospital Organization Sakakibara Hospital, 777 Sakakibara, Tsu, Mie 514-1292, Japan;
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4
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McClure MJ, Ramey AN, Rashid M, Boyan BD, Schwartz Z. Integrin-α7 signaling regulates connexin 43, M-cadherin, and myoblast fusion. Am J Physiol Cell Physiol 2019; 316:C876-C887. [PMID: 30892939 DOI: 10.1152/ajpcell.00282.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Regenerative medicine treatments for severe skeletal muscle injuries are limited, resulting in persistent functional deficits. Clinical options include neglecting the wound with the expectation that fibrosis will develop or using an autologous muscle graft with minimal functional improvement. A regenerative matrix can be used, but muscle fiber development on these matrices remains a challenge in vivo. Here, we explored the fundamental mechanisms that mediate cell-substrate signaling and its effect on cell-cell communication during myoblast fusion and tube formation to improve outcomes following implantation of matrices used to stimulate muscle regeneration. We previously reported that integrin-α7 was increased on anisotropic biomaterials, suggesting a role for α7β1 signaling in myoblast communication via connexin 43 and M-cadherin. Our results demonstrated that α7 silencing blocked expression of myogenic differentiation factor 1 (Myod), myogenin (Myog), myogenic factor 6 (Myf6), myosin heavy chain type 1 (Myh1), and transmembrane protein 8c (Tmem8c), indicating that myoblast fusion was inhibited. Expression of α5 and M-cadherin decreased but β1 and connexin 43 increased. We examined protein production and observed reduced extracellular-signal regulated kinase 1/2 (ERK) in α7-silenced cells that correlated with upregulation of connexin 43 and M-cadherin, suggesting a compensatory pathway. These results indicate that α7 signaling plays a critical role in ex vivo fusion and implicates a relationship with connexin 43 and M-cadherin.
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Affiliation(s)
- Michael J McClure
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia
| | - Allison N Ramey
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia
| | - Mashaba Rashid
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia
| | - Barbara D Boyan
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia.,Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology , Atlanta, Georgia
| | - Zvi Schwartz
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia.,Department of Periodontics, University of Texas Health Sciences Center at San Antonio , San Antonio, Texas
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5
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Ayanlaja AA, Zhang B, Ji G, Gao Y, Wang J, Kanwore K, Gao D. The reversible effects of glial cell line-derived neurotrophic factor (GDNF) in the human brain. Semin Cancer Biol 2018; 53:212-222. [PMID: 30059726 DOI: 10.1016/j.semcancer.2018.07.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 07/10/2018] [Accepted: 07/18/2018] [Indexed: 12/20/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) is a potent survival factor, and a member of the transforming growth factor β (TGF-β) superfamily acting on different neuronal activities. GDNF was originally identified as a neurotrophic factor crucially involved in the survival of dopaminergic neurons of the nigrostriatal pathway and is currently an established therapeutic target in Parkinson's disease. However, GDNF was later reported to be highly expressed in gliomas, especially in glioblastomas, and was demonstrated as a potent proliferation factor involved in the development and migration of gliomas. Here, we review our current understanding and progress made so far by researchers in our laboratories with references to relevant articles to support our discoveries. We present past and recent discoveries on the mechanisms involved in the protection of neurons by GDNF and examine its emerging roles in gliomas, as well as reasons for the abnormal expression in Glioblastoma Multiforme (GBM). Collectively, our work establishes a paradigm by which the ability of GDNF to protect dopaminergic neurons from degradation and its corresponding effects on glioma cells points to an underlying biological vulnerability in the effects of GDNF in the normal brain which can be subverted for use by cancer cells. Hence, presenting novel opportunities for intervention in glioma therapies.
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Affiliation(s)
- Abiola Abdulrahman Ayanlaja
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - Baole Zhang
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - GuangQuan Ji
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - Yue Gao
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - Jie Wang
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - Kouminin Kanwore
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - DianShuai Gao
- Xuzhou Key Laboratory of Neurobiology, Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China.
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6
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Connexin 43 regulates the expression of wound healing-related genes in human gingival and skin fibroblasts. Exp Cell Res 2018; 367:150-161. [PMID: 29596891 DOI: 10.1016/j.yexcr.2018.03.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/23/2018] [Accepted: 03/24/2018] [Indexed: 12/21/2022]
Abstract
Fibroblasts are the most abundant connective tissue cells and play an important role in wound healing. It is possible that faster and scarless wound healing in oral mucosal gingiva relative to skin may relate to the distinct phenotype of the fibroblasts residing in these tissues. Connexin 43 (Cx43) is the most ubiquitous Cx in skin (SFBLs) and gingival fibroblasts (GFBLs), and assembles into hemichannels (HCs) and gap junctions (GJs) on the cell membrane. We hypothesized that SFBLs and GFBLs display distinct expression or function of Cx43, and that this may partly underlie the different wound healing outcomes in skin and gingiva. Here we show that Cx43 distinctly formed Cx43 GJs and HCs in human skin and gingiva in vivo. However, in SFBLs, in contrast to GFBLs, only a small proportion of total Cx43 assembled into HC plaques. Using an in vivo-like 3D culture model, we further show that the GJ, HC, and channel-independent functions of Cx43 distinctly regulated wound healing-related gene expression in GFBLs and SFBLs. Therefore, the distinct wound healing outcomes in skin and gingiva may partly relate to the inherently different assembly and function of Cx43 in the resident fibroblasts.
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7
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Pecoraro M, Pinto A, Popolo A. Inhibition of Connexin 43 translocation on mitochondria accelerates CoCl2-induced apoptotic response in a chemical model of hypoxia. Toxicol In Vitro 2018; 47:120-128. [DOI: 10.1016/j.tiv.2017.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 10/24/2017] [Accepted: 11/14/2017] [Indexed: 12/19/2022]
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8
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Michela P, Velia V, Aldo P, Ada P. Role of connexin 43 in cardiovascular diseases. Eur J Pharmacol 2015; 768:71-6. [PMID: 26499977 DOI: 10.1016/j.ejphar.2015.10.030] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/08/2015] [Accepted: 10/16/2015] [Indexed: 12/21/2022]
Abstract
Gap junctions (GJs) channels provide the basis for intercellular communication in the cardiovascular system for maintenance of the normal cardiac rhythm, regulation of vascular tone and endothelial function as well as metabolic interchange between the cells. They allow the transfer of small molecules and may enable slow calcium wave spreading, transfer of "death" or of "survival" signals. In the cardiomyocytes the most abundant isoform is Connexin 43 (Cx43). Alterations in Cx43 expression and distribution were observed in myocardium disease; i.e. in hypertrophic cardiomyopathy, heart failure and ischemia. Recent reports suggest the presence of Cx43 in the mitochondria as well, at least in the inner mitochondrial membrane, where it plays a central role in ischemic preconditioning. In this review, the current knowledge on the relationship between the remodeling of cardiac gap junctions and cardiac diseases are summarized.
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Affiliation(s)
| | | | - Pinto Aldo
- Department of Pharmacy, University of Salerno, Italy
| | - Popolo Ada
- Department of Pharmacy, University of Salerno, Italy.
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9
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Baker MW, Macagno ER. Control of neuronal morphology and connectivity: Emerging developmental roles for gap junctional proteins. FEBS Lett 2014; 588:1470-9. [DOI: 10.1016/j.febslet.2014.02.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 02/10/2014] [Accepted: 02/12/2014] [Indexed: 11/25/2022]
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10
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Defamie N, Chepied A, Mesnil M. Connexins, gap junctions and tissue invasion. FEBS Lett 2014; 588:1331-8. [PMID: 24457198 DOI: 10.1016/j.febslet.2014.01.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/13/2014] [Accepted: 01/14/2014] [Indexed: 12/14/2022]
Abstract
Formation of metastases negatively impacts the survival prognosis of cancer patients. Globally, if the various steps involved in their formation are relatively well identified, the molecular mechanisms responsible for the emergence of invasive cancer cells are still incompletely resolved. Elucidating what are the mechanisms that allow cancer cells to evade from the tumor is a crucial point since it is the first step of the metastatic potential of a solid tumor. In order to be invasive, cancer cells have to undergo transformations such as down-regulation of cell-cell adhesions, modification of cell-matrix adhesions and acquisition of proteolytic properties. These transformations are accompanied by the capacity to "activate" stromal cells, which may favor the motility of the invasive cells through the extracellular matrix. Since modulation of gap junctional intercellular communication is known to be involved in cancer, we were interested to consider whether these different transformations necessary for the acquisition of invasive phenotype are related with gap junctions and their structural proteins, the connexins. In this review, emerging roles of connexins and gap junctions in the process of tissue invasion are proposed.
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Affiliation(s)
- Norah Defamie
- Team IP2C, STIM laboratory, University of Poitiers, CNRS ERL 7368, 1 rue Georges Bonnet, B36, 86073 Poitiers Cedex9, France.
| | - Amandine Chepied
- Team IP2C, STIM laboratory, University of Poitiers, CNRS ERL 7368, 1 rue Georges Bonnet, B36, 86073 Poitiers Cedex9, France.
| | - Marc Mesnil
- Team IP2C, STIM laboratory, University of Poitiers, CNRS ERL 7368, 1 rue Georges Bonnet, B36, 86073 Poitiers Cedex9, France.
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11
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Yu SC, Xiao HL, Jiang XF, Wang QL, Li Y, Yang XJ, Ping YF, Duan JJ, Jiang JY, Ye XZ, Xu SL, Xin YH, Yao XH, Chen JH, Chu WH, Sun W, Wang B, Wang JM, Zhang X, Bian XW. Connexin 43 reverses malignant phenotypes of glioma stem cells by modulating E-cadherin. Stem Cells 2012; 30:108-20. [PMID: 22131169 DOI: 10.1002/stem.1685] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Malfunctioned gap junctional intercellular communication (GJIC) has been thought associated with malignant transformation of normal cells. However, the role of GJIC-related proteins such as connexins in sustaining the malignant behavior of cancer stem cells remains unclear. In this study, we obtained tumorspheres formed by glioma stem cells (GSCs) and adherent GSCs and then examined their GJIC. All GSCs showed reduced GJIC, and differentiated glioma cells had more gap junction-like structures than GSCs. GSCs expressed very low level of connexins, Cx43 in particular, which are key components of gap junction. We observed hypermethylation in the promoter of gap junction protein α1, which encodes Cx43 in GSCs. Reconstitution of Cx43 in GSCs inhibited their capacity of self-renewal, invasiveness, and tumorigenicity via influencing E-cadherin and its coding protein, which leads to changes in the expression of Wnt/β-catenin targeting genes. Our results suggest that GSCs require the low expression of Cx43 for maintaining their malignant phenotype, and upregulation of Cx43 might be a potential strategy for treatment of malignant glioma.
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Affiliation(s)
- Shi-Cang Yu
- Institute of Pathology and Southwest Cancer Center, Third Military Medical University, Chongqing, China
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12
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Non-channel functions of connexins in cell growth and cell death. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:2002-8. [PMID: 21718687 DOI: 10.1016/j.bbamem.2011.06.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/08/2011] [Accepted: 06/15/2011] [Indexed: 12/12/2022]
Abstract
Cellular communication mediated by gap junction channels and hemichannels, both composed of connexin proteins, constitutes two acknowledged regulatory platforms in the accomplishment of tissue homeostasis. In recent years, an abundance of reports has been published indicating functions for connexin proteins in the control of the cellular life cycle that occur independently of their channel activities. This has yet been most exemplified in the context of cell growth and cell death, and is therefore as such addressed in the current paper. Specific attention is hereby paid to the molecular mechanisms that underpin the cellular non-channel roles of connexin proteins, namely the alteration of the expression of tissue homeostasis determinants and the physical interaction with cell growth and cell death regulators. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Aberrant distributions and relationships among E-cadherin, beta-catenin, and connexin 26 and 43 in endometrioid adenocarcinomas. Int J Gynecol Pathol 2010; 29:358-65. [PMID: 20567150 DOI: 10.1097/pgp.0b013e3181c3c57f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
During carcinogenesis, loss of intracellular cohesion is observed among cancer cells with altered expression of such adhesion molecules as E-cadherin and beta-catenin, and aberrant expression and cellular location of intercellular gap junction proteins-connexins. The aim of this study was to evaluate immunohistochemically the expression and relationship between E-cadherin and beta-catenin, and the connexins Cx26 and Cx43 in 86 endometrioid adenocarcinomas. The aberrant cytoplasmic translocation of the studied proteins was a predominant finding, whereas only a minority of cases showed normal, nuclear beta-catenin labeling or membranous distribution of the remaining molecules. E-cadherin was positively and significantly associated with beta-catenin (P=0.001, r=0.366), as was Cx26 with Cx43 (P<0.001, r=0.719), E-cadherin with Cx26 (P<0.001, r=0.413), and E-cadherin and Cx43 (P<0.001, r=0.434) in all cancers. A subgroup of endometrioid adenocarcinomas (FIGO IB+II) exclusively showed a positive significant association between the expression of beta-catenin and Cx26 (P=0.038, r=0.339). In addition, there were significantly more beta-catenin-positive carcinomas among superficially spreading cancers (FIGO IA) than among deeper invading neoplasms (FIGO IB+II) (P=0.056). The altered location of the studied proteins indicates impairment of their physiological functions. In particular, normal membranous distribution of E-cadherin and connexins is lost and replaced by abnormal cytoplasmic accumulation in most cancers, and thus intercellular ties are expected to be weakened and loosened as a consequence. In contrast, the lack of relationship between beta-catenin and connexins, E-cadherin seems to be closely associated with the expression of Cx26 and Cx43 in endometrioid adenocarcinomas.
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14
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Cao JP, Li FZ, Zhu YY, Yuan HH, Yu ZQ, Gao DS. Expressions and possible roles of GDNF receptors in the developing dopaminergic neurons. Brain Res Bull 2010; 83:321-30. [PMID: 20884338 DOI: 10.1016/j.brainresbull.2010.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2009] [Revised: 08/11/2010] [Accepted: 09/17/2010] [Indexed: 01/16/2023]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) has an essential role in the survival and maturation of the dopaminergic (DA) neurons in the substantia nigra (SN) of mammalian embryonic brain. In addition to Ret, cell adhesion molecules (CAMs) were also proposed to function as transmembrane signaling receptors of GDNF. The present study was to investigate whether these transmembrane receptors of GDNF were correlated with the tyrosine hydroxylase (TH) expression of SN DA neurons during early developmental stage. RT-PCR and Western blot were performed to detect TH expression in SN of perinatal rats at mRNA and protein level respectively; meanwhile, Western blot was performed to detect the expressions of the transmembrane proteins including Ret, neural cell adhesion molecule-140 (NCAM-140), integrin β1 and N-cadherin. The results showed that TH mRNA expression was positively correlated with both Ret and N-cadherin protein, while there was no correlation with NCAM-140 and integrin β1; TH protein expression was correlated with all of these transmembrane molecules. These data suggested that the expression of either TH mRNA or TH protein was subject to the mediation of different transmembrane receptor combinations of GDNF.
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Affiliation(s)
- Jun Ping Cao
- Department of Neurobiology and Human Anatomy, Xuzhou Medical College, 84 West Huaihai Road, Xuzhou, Jiangsu 221002, PR China
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15
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Cell membrane permeabilization via connexin hemichannels in living and dying cells. Exp Cell Res 2010; 316:2377-89. [DOI: 10.1016/j.yexcr.2010.05.026] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 05/20/2010] [Accepted: 05/21/2010] [Indexed: 12/31/2022]
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16
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Vinken M, Decrock E, De Vuyst E, Ponsaerts R, D'hondt C, Bultynck G, Ceelen L, Vanhaecke T, Leybaert L, Rogiers V. Connexins: sensors and regulators of cell cycling. Biochim Biophys Acta Rev Cancer 2010; 1815:13-25. [PMID: 20801193 DOI: 10.1016/j.bbcan.2010.08.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 08/18/2010] [Accepted: 08/20/2010] [Indexed: 12/13/2022]
Abstract
It is nowadays well established that gap junctions are critical gatekeepers of cell proliferation, by controlling the intercellular exchange of essential growth regulators. In recent years, however, it has become clear that the picture is not as simple as originally anticipated, as structural precursors of gap junctions can affect cell cycling by performing actions not related to gap junctional intercellular communication. Indeed, connexin hemichannels also foresee a pathway for cell growth communication, albeit between the intracellular compartment and the extracellular environment, while connexin proteins as such can directly or indirectly influence the production of cell cycle regulators independently of their channel activities. Furthermore, a novel set of connexin-like proteins, the pannexins, have lately joined in as regulators of the cell proliferation process, which they can affect as either single units or as channel entities. In the current paper, these multifaceted aspects of connexin-related signalling in cell cycling are reviewed.
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Affiliation(s)
- Mathieu Vinken
- Department of Toxicology, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium.
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17
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Bobbie MW, Roy S, Trudeau K, Munger SJ, Simon AM, Roy S. Reduced connexin 43 expression and its effect on the development of vascular lesions in retinas of diabetic mice. Invest Ophthalmol Vis Sci 2010; 51:3758-63. [PMID: 20130277 DOI: 10.1167/iovs.09-4489] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE. To examine whether diabetes-induced connexin 43 downregulation promotes retinal vascular lesions characteristic of diabetic retinopathy (DR). METHODS. Two animal models, streptozotocin-induced diabetic mice and Cx43 heterozygous knockout (Cx43(+/-)) mice, were studied to directly assess whether diabetes reduces the expression of retinal Cx43, which, in turn, contributes to retinal vascular cell loss by apoptosis. Retinal Cx43 protein levels were assessed in nondiabetic control mice, diabetic mice, and Cx43(+/-) mice by Western blot analysis, and Cx43 localization and distribution in the retinal vascular cells were studied by immunostaining of retinal trypsin digests (RTDs). In parallel, RTDs were stained with hematoxylin and periodic acid Schiff to determine pericyte loss (PL) and acellular capillaries (AC), and TUNEL assays were performed to determine retinal vascular cell apoptosis. RESULTS. Western blot analysis indicated significant reductions in retinal Cx43 protein levels in diabetic mice and Cx43(+/-) mice compared with those of nondiabetic mice. Similarly, a significant reduction in Cx43 immunostaining was observed in the retinal capillaries of diabetic mice and Cx43(+/-) mice compared with those of control mice. Both diabetic and age-matched Cx43(+/-) mice exhibited increased amount of PL, AC, and TUNEL-positive cells compared with control mice. CONCLUSIONS. Diabetes-induced inhibition of Cx43 expression contributes to vascular cell apoptosis in retinas of diabetic mice. This suggests that reduced Cx43 expression plays a critical role in the development of AC and PL associated with DR.
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Affiliation(s)
- Michael W Bobbie
- Departments of Medicine, University of Arizona, Tucson, Arizona, USA
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Smyth JW, Hong TT, Gao D, Vogan JM, Jensen BC, Fong TS, Simpson PC, Stainier DYR, Chi NC, Shaw RM. Limited forward trafficking of connexin 43 reduces cell-cell coupling in stressed human and mouse myocardium. J Clin Invest 2009; 120:266-79. [PMID: 20038810 DOI: 10.1172/jci39740] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 11/11/2009] [Indexed: 12/25/2022] Open
Abstract
Gap junctions form electrical conduits between adjacent myocardial cells, permitting rapid spatial passage of the excitation current essential to each heartbeat. Arrhythmogenic decreases in gap junction coupling are a characteristic of stressed, failing, and aging myocardium, but the mechanisms of decreased coupling are poorly understood. We previously found that microtubules bearing gap junction hemichannels (connexons) can deliver their cargo directly to adherens junctions. The specificity of this delivery requires the microtubule plus-end tracking protein EB1. We performed this study to investigate the hypothesis that the oxidative stress that accompanies acute and chronic ischemic disease perturbs connexon forward trafficking. We found that EB1 was displaced in ischemic human hearts, stressed mouse hearts, and isolated cells subjected to oxidative stress. As a result, we observed limited microtubule interaction with adherens junctions at intercalated discs and reduced connexon delivery and gap junction coupling. A point mutation within the tubulin-binding domain of EB1 reproduced EB1 displacement and diminished connexon delivery, confirming that EB1 displacement can limit gap junction coupling. In zebrafish hearts, oxidative stress also reduced the membrane localization of connexin and slowed the spatial spread of excitation. We anticipate that protecting the microtubule-based forward delivery apparatus of connexons could improve cell-cell coupling and reduce ischemia-related cardiac arrhythmias.
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Affiliation(s)
- James W Smyth
- Cardiovascular Research Institute, Department of Medicine, University of California-San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143, USA
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Rhee DY, Zhao XQ, Francis RJB, Huang GY, Mably JD, Lo CW. Connexin 43 regulates epicardial cell polarity and migration in coronary vascular development. Development 2009; 136:3185-93. [PMID: 19700622 DOI: 10.1242/dev.032334] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Connexin 43 knockout (Cx43 KO) mice exhibit conotruncal malformations and coronary artery defects. We observed epicardial blisters in the Cx43 KO hearts that suggest defects in epicardial epithelial-mesenchymal transformation (EMT), a process that generates coronary vascular progenitors. Analysis using a three-dimensional collagen gel invasion assay showed that Cx43 KO epicardial cells are less invasive and that, unlike wild-type epicardial cells, they fail to organize into thin vessel-like projections. Examination of Cx43 KO hearts using Wt1 as an epicardial marker revealed a disorganized pattern of epicardial cell infiltration. Time-lapse imaging and motion analysis using epicardial explants showed a defect in directional cell migration. This was associated with changes in the actin/tubulin cytoskeleton. A defect in cell polarity was indicated by a failure of the microtubule-organizing center to align with the direction of cell migration. Forced expression of Cx43 constructs in epicardial explants showed the Cx43 tubulin-binding domain is required for Cx43 modulation of cell polarity and cell motility. Pecam staining revealed early defects in remodeling of the primitive coronary vascular plexuses in the Cx43 KO heart. Together, these findings suggest an early defect in coronary vascular development arising from a global perturbation of the cytoarchitecture of the cell. Consistent with this, we found aberrant myocardialization of the outflow tract, a process also known to be EMT dependent. Together, these findings suggest cardiac defects in the Cx43 KO mice arise from the disruption of cell polarity, a process that may be dependent on Cx43-tubulin interactions.
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Affiliation(s)
- David Y Rhee
- Laboratory of Developmental Biology, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Liu J, Zhang W, Liu J, Lu X, Long Y, Zhou Y, Liu S. Expressions of connexin and par-3 in the distal margin of rectal cancer after ultra-low anterior resection. ACTA ACUST UNITED AC 2009; 29:330-4. [DOI: 10.1007/s11596-009-0313-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2008] [Indexed: 01/19/2023]
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Liu J, Liu SH, Liu JL, Zhao G, Zhang WK. Changes in expression of Connexin and Par-3 in colorectal cancer. Shijie Huaren Xiaohua Zazhi 2009; 17:785-789. [DOI: 10.11569/wcjd.v17.i8.785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the expression change and characteristics of Connexin and protease activated receptor 3 (Par-3) and to investigate their clinical significance in colorectal tumor.
METHODS: The 51 tissue samples were collected and divided into three groups: tumor tissue group, tissue adjacent to tumor group (2.0 cm), and normal tissue group (apart from tumor >5.0 cm) respectively. Morphological changes of cells were observed using electronic microscopy, histopathological changes were detected using HE staining, and the expressions of Connexin and Par-3 were detected immunohistochemistry and Western blot.
RESULTS: The tumor tissue was deformed and epithelium polarity was vanished, compared with normal tissue. On electronic microscopy, the organelles of the tumor epithelium was in disorder and the structure of cell junctions, such as tight junction, intermediate junction were disarranged or disappeared. For normal tissue group, epithelial cells were regular in shape, the cell polarity was clear, and the cell junction structure was integrated. Immunohistochemistry showed the expression levels of Connexin and Par-3 were gradually decreased, in such order as normal tissue group (0.572 ± 0.051, 0.485 ± 0.042), tissue adjacent to tumor group (0.432 ± 0.049, 0.367 ± 0.035), and tumor tissue of colorectum group (0.290 ± 0.041, 0.227 ± 0.031). There had been significant difference among them (P < 0.05).
CONCLUSION: Down-regulation of Connexin and Par-3 expression is premonition for cancer cell aggravation and metastasis.
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