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Novielli-Kuntz NM, Jelen M, Barr K, DeLalio LJ, Feng Q, Isakson BE, Gros R, Laird DW. Ablation of both Cx40 and Panx1 results in similar cardiovascular phenotypes exhibited in Cx40 knockout mice. Biosci Rep 2019; 39:BSR20182350. [PMID: 30745457 PMCID: PMC6393227 DOI: 10.1042/bsr20182350] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/10/2019] [Accepted: 02/05/2019] [Indexed: 11/30/2022] Open
Abstract
Connexins (Cxs) and pannexins (Panxs) are highly regulated large-pore channel-forming proteins that participate in cellular communication via small molecular exchange with the extracellular microenvironment, or in the case of connexins, directly between cells. Given the putative functional overlap between single membrane-spanning connexin hemichannels and Panx channels, and cardiovascular system prevalence, we generated the first Cx40-/-Panx1-/- mouse with the anticipation that this genetic modification would lead to a severe cardiovascular phenotype. Mice null for both Cx40 and Panx1 produced litter sizes and adult growth progression similar to wild-type (WT), Cx40-/- and Panx1-/- mice. Akin to Cx40-/- mice, Cx40-/-Panx1-/- mice exhibited cardiac hypertrophy and elevated systolic, diastolic, and mean arterial blood pressure compared with WT and Panx1-/- mice; however assessment of left ventricular ejection fraction and fractional shortening revealed no evidence of cardiac dysfunction between groups. Furthermore, Cx40-/-, Panx1-/-, and Cx40-/-Panx1-/- mice demonstrated impaired endothelial-mediated vasodilation of aortic segments to increasing concentrations of methacholine (MCh) compared with WT, highlighting roles for both Cx40 and Panx1 in vascular endothelial cell (EC) function. Surprisingly, elevated kidney renin mRNA expression, plasma renin activity, and extraglomerular renin-producing cell populations found in Cx40-/- mice was further exaggerated in double knockout mice. Thus, while gestation and gross development were conserved in Cx40-/-Panx1-/- mice, they exhibit cardiac hypertrophy, hypertension, and impaired endothelial-mediated vasodilation that phenocopies Cx40-/- mice. Nevertheless, the augmented renin homeostasis observed in the double knockout mice suggests that both Cx40 and Panx1 may play an integrative role.
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Affiliation(s)
| | - Meghan Jelen
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Canada
| | - Kevin Barr
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Canada
| | - Leon J DeLalio
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, U.S.A
| | - Qingping Feng
- Department of Physiology and Pharmacology London, ON, Canada
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, U.S.A
| | - Robert Gros
- Department of Physiology and Pharmacology London, ON, Canada
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Canada
- Department of Physiology and Pharmacology London, ON, Canada
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Zhou KQ, Green CR, Bennet L, Gunn AJ, Davidson JO. The Role of Connexin and Pannexin Channels in Perinatal Brain Injury and Inflammation. Front Physiol 2019; 10:141. [PMID: 30873043 PMCID: PMC6400979 DOI: 10.3389/fphys.2019.00141] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/07/2019] [Indexed: 12/21/2022] Open
Abstract
Perinatal brain injury remains a major cause of death and life-long disability. Perinatal brain injury is typically associated with hypoxia-ischemia and/or infection/inflammation. Both hypoxia-ischemia and infection trigger an inflammatory response in the brain. The inflammatory response can contribute to brain cell loss and chronic neuroinflammation leading to neurological impairments. It is now well-established that brain injury evolves over time, and shows a striking spread from injured to previously uninjured regions of the brain. There is increasing evidence that this spread is related to opening of connexin hemichannels and pannexin channels, both of which are large conductance membrane channels found in almost all cell types in the brain. Blocking connexin hemichannels within the first 3 h after hypoxia-ischemia has been shown to improve outcomes in term equivalent fetal sheep but it is important to also understand the downstream pathways linking membrane channel opening with the development of injury in order to identify new therapeutic targets. Open membrane channels release adenosine triphosphate (ATP), and other neuroactive molecules, into the extracellular space. ATP has an important physiological role, but has also been reported to act as a damage-associated molecular pattern (DAMP) signal mediated through specific purinergic receptors and so act as a primary signal 1 in the innate immune system inflammasome pathway. More crucially, extracellular ATP is a key inflammasome signal 2 activator, with purinergic receptor binding triggering the assembly of the multi-protein inflammasome complex. The inflammasome pathway and complex formation contribute to activation of inflammatory caspases, and the release of inflammatory cytokines, including interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-18, and vascular endothelial growth factor (VEGF). We propose that the NOD-like receptor protein-3 (NLRP3) inflammasome, which has been linked to inflammatory responses in models of ischemic stroke and various inflammatory diseases, may be one mechanism by which connexin hemichannel opening especially mediates perinatal brain injury.
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Affiliation(s)
- Kelly Q Zhou
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- Department of Physiology, The University of Auckland, Auckland, New Zealand.,Department of Ophthalmology, The University of Auckland, Auckland, New Zealand
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Mugisho OO, Green CR, Zhang J, Acosta ML, Rupenthal ID. Connexin43 hemichannels: A potential drug target for the treatment of diabetic retinopathy. Drug Discov Today 2019; 24:1627-1636. [PMID: 30690195 DOI: 10.1016/j.drudis.2019.01.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 01/17/2019] [Accepted: 01/17/2019] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is a chronic vascular disease of the retina that causes vision loss in patients with type 1 and type 2 diabetes, and is associated with vascular dysfunction and occlusion, retinal oedema, haemorrhage and inadequate growth of new blood vessels. Current DR therapies primarily target downstream, later-stage vascular defects with a significant proportion of diabetic macular oedema patients being non-responders. Moreover, other evidence suggests that prolonged use of therapies targeting vascular endothelial growth factor (VEGF) might be associated with increased onset of geographic atrophy and retinal ganglion cell death. It is therefore highly desirable to prevent the onset of DR or arrest its progression at a stage preceding the appearance of more-advanced pathology by targeting upstream disease mechanisms. Connexin43 hemichannels play a part in the pathogenesis of chronic inflammatory diseases, including inflammasome pathway activation; and hemichannel block has been shown to alleviate vascular leak and inflammation. This review discusses the inflammatory changes occurring in DR as well as current therapies and their limitations. It then focuses on the role of connexin43 in DR, providing evidence for the utility of connexin43 hemichannel blockers as novel therapeutics for DR treatment.
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Affiliation(s)
- Odunayo O Mugisho
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Jie Zhang
- Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Monica L Acosta
- School of Optometry and Vision Science and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Ilva D Rupenthal
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand.
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54
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Connexin43 mutations linked to skin disease have augmented hemichannel activity. Sci Rep 2019; 9:19. [PMID: 30631135 PMCID: PMC6328547 DOI: 10.1038/s41598-018-37221-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 12/04/2018] [Indexed: 01/22/2023] Open
Abstract
Mutations in the gene (GJA1) encoding connexin43 (Cx43) are responsible for several rare genetic disorders, including non-syndromic skin-limited diseases. Here we used two different functional expression systems to characterize three Cx43 mutations linked to palmoplantar keratoderma and congenital alopecia-1, erythrokeratodermia variabilis et progressiva, or inflammatory linear verrucous epidermal nevus. In HeLa cells and Xenopus oocytes, we show that Cx43-G8V, Cx43-A44V and Cx43-E227D all formed functional gap junction channels with the same efficiency as wild-type Cx43, with normal voltage gating and a unitary conductance of ~110 pS. In HeLa cells, all three mutations also localized to regions of cell-cell contact and displayed a punctate staining pattern. In addition, we show that Cx43-G8V, Cx43-A44V and Cx43-E227D significantly increase membrane current flow through formation of active hemichannels, a novel activity that was not displayed by wild-type Cx43. The increased membrane current was inhibited by either 2 mM calcium, or 5 µM gadolinium, mediated by hemichannels with a unitary conductance of ~250 pS, and was not due to elevated mutant protein expression. The three Cx43 mutations all showed the same gain of function activity, suggesting that augmented hemichannel activity could play a role in skin-limited diseases caused by human Cx43 mutations.
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Sinyuk M, Mulkearns-Hubert EE, Reizes O, Lathia J. Cancer Connectors: Connexins, Gap Junctions, and Communication. Front Oncol 2018; 8:646. [PMID: 30622930 PMCID: PMC6308394 DOI: 10.3389/fonc.2018.00646] [Citation(s) in RCA: 55] [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: 09/15/2018] [Accepted: 12/10/2018] [Indexed: 12/21/2022] Open
Abstract
Despite concerted clinical and research efforts, cancer is a leading cause of death worldwide. Surgery, radiation, and chemotherapy have remained the most common standard-of-care strategies against cancer for decades. However, the side effects of these therapies demonstrate the need to investigate adjuvant novel treatment modalities that minimize the harm caused to healthy cells and tissues. Normal and cancerous cells require communication amongst themselves and with their surroundings to proliferate and drive tumor growth. It is vital to understand how intercellular and external communication impacts tumor cell malignancy. To survive and grow, tumor cells, and their normal counterparts utilize cell junction molecules including gap junctions (GJs), tight junctions, and adherens junctions to provide contact points between neighboring cells and the extracellular matrix. GJs are specialized structures composed of a family of connexin proteins that allow the free diffusion of small molecules and ions directly from the cytoplasm of adjacent cells, without encountering the extracellular milieu, which enables rapid, and coordinated cellular responses to internal and external stimuli. Importantly, connexins perform three main cellular functions. They enable direct gap junction intercellular communication (GJIC) between cells, form hemichannels to allow cell communication with the extracellular environment, and serve as a site for protein-protein interactions to regulate signaling pathways. Connexins themselves have been found to promote tumor cell growth and invasiveness, contributing to the overall tumorigenicity and have emerged as attractive anti-tumor targets due to their functional diversity. However, connexins can also serve as tumor suppressors, and therefore, a complete understanding of the roles of the connexins and GJs in physiological and pathophysiological conditions is needed before connexin targeting strategies are applied. Here, we discuss how the three aspects of connexin function, namely GJIC, hemichannel formation, and connexin-protein interactions, function in normal cells, and contribute to tumor cell growth, proliferation, and death. Finally, we discuss the current state of anti-connexin therapies and speculate which role may be most amenable for the development of targeting strategies.
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Affiliation(s)
- Maksim Sinyuk
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, OH, United States
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Erin E. Mulkearns-Hubert
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Ofer Reizes
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, OH, United States
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, OH, United States
- Case Comprehensive Cancer Center, Case Western University, Cleveland, OH, United States
| | - Justin Lathia
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, OH, United States
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, OH, United States
- Case Comprehensive Cancer Center, Case Western University, Cleveland, OH, United States
- Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
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Youssefian L, Vahidnezhad H, Saeidian AH, Mahmoudi H, Karamzadeh R, Kariminejad A, Huang J, Li L, Jannace TF, Fortina P, Zeinali S, White TW, Uitto J. A novel autosomal recessive GJB2-associated disorder: Ichthyosis follicularis, bilateral severe sensorineural hearing loss, and punctate palmoplantar keratoderma. Hum Mutat 2018; 40:217-229. [PMID: 30431684 DOI: 10.1002/humu.23686] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/26/2018] [Accepted: 10/30/2018] [Indexed: 11/07/2022]
Abstract
Ichthyosis follicularis, a distinct cutaneous entity reported in combination with atrichia, and photophobia has been associated with mutations in MBTPS2. We sought the genetic cause of a novel syndrome of ichthyosis follicularis, bilateral severe sensorineural hearing loss and punctate palmoplantar keratoderma in two families. We performed whole exome sequencing on three patients from two families. The pathogenicity and consequences of mutations were studied in the Xenopus oocyte expression system and by molecular modeling analysis. Compound heterozygous mutations in the GJB2 gene were discovered: a pathogenic c.526A>G; p.Asn176Asp, and a common frameshift mutation, c.35delG; p.Gly12Valfs*2. The p.Asn176Asp missense mutation was demonstrated to significantly reduce the cell-cell gap junction channel activity and increase the nonjunctional hemichannel activity in the Xenopus oocyte expression system. Molecular modeling analyses of the mutant Cx26 protein revealed significant changes in the structural characteristics and electrostatic potential of the Cx26, either in hemichannel or gap junction conformation. Thus, association of a new syndrome of an autosomal recessive disorder of ichthyosis follicularis, bilateral severe sensorineural hearing loss and punctate palmoplantar keratoderma with mutations in GJB2, expands the phenotypic spectrum of the GJB2-associated disorders. The findings attest to the complexity of the clinical consequences of different mutations in GJB2.
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Affiliation(s)
- Leila Youssefian
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Genetics, Genomics and Cancer Biology PhD Program, Thomas Jefferson University, Philadelphia, PA, USA
| | - Hassan Vahidnezhad
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
- Biotechnology Research Center, Department of Molecular Medicine, Pasteur Institute of Iran, Tehran, Iran
| | - Amir Hossein Saeidian
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
- Genetics, Genomics and Cancer Biology PhD Program, Thomas Jefferson University, Philadelphia, PA, USA
| | - Hamidreza Mahmoudi
- Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Razieh Karamzadeh
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | | | - Jianhe Huang
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Leping Li
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA
| | - Thomas F Jannace
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA
| | - Paolo Fortina
- Department of Cancer Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
- Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Sirous Zeinali
- Biotechnology Research Center, Department of Molecular Medicine, Pasteur Institute of Iran, Tehran, Iran
| | - Thomas W White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
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Wang Q, Zhou C, Li X, Cai L, Zou J, Zhang D, Xie J, Lai W. TGF-β1 promotes gap junctions formation in chondrocytes via Smad3/Smad4 signalling. Cell Prolif 2018; 52:e12544. [PMID: 30444057 PMCID: PMC6495951 DOI: 10.1111/cpr.12544] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/04/2018] [Accepted: 09/21/2018] [Indexed: 02/05/2023] Open
Abstract
Objectives Connexin‐mediated functional gap junction intercellular communication (GJIC) has a vital role in development, homeostasis and pathology. Transforming growth factor‐β1 (TGF‐β1), as one of the most vital factors in chondrocytes, promotes cartilage precursor cell differentiation and chondrocyte proliferation, migration and metabolism. However, how TGF‐β1 mediates GJIC in chondrocytes remains unclear. This study aims to determine the influence of TGF‐β1 on GJIC in mouse chondrocytes and its underlying mechanism. Methods qPCR and mRNA microarray were used to verify the expression of genes in the TGF‐β and connexin families in cartilage and chondrocytes. A scrape loading/dye transfer assay was performed to explore GJIC. Western blot analysis was used to detect connexin43 (Cx43) and Smad signalling components. Immunofluorescence staining was performed to characterize protein distribution. Results The TGF‐β1 mRNA was the highest expressed member of the TGFβ super family in cartilage. TGF‐β1 promoted functional GJIC through increased expression of Cx43. TGF‐β1‐mediated GJIC required the participation of TGF‐β type I receptor. TGF‐β1 activated Smad3 and Smad4 signalling to facilitate their nuclear translocation. The Smad3 and Smad4 signalling proteins bound to the promoter of Gja1 and thus initiated Cx43 gene expression. Conclusions For the first time, these results revealed a vital role of TGF‐β1 in cell‐cell communication in chondrocytes via gap junction formation. We describe the regulatory mechanism, the involvement of TGF‐β type I receptor and the nuclear translocation of Smad3/4.
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Affiliation(s)
- Qingxuan Wang
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Chenchen Zhou
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xiaobing Li
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Linyi Cai
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Zou
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Demao Zhang
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Wenli Lai
- State Key Laboratory of Oral Diseases, Orthodontics Department, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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Direct Cell⁻Cell Interactions in the Endometrium and in Endometrial Pathophysiology. Int J Mol Sci 2018; 19:ijms19082227. [PMID: 30061539 PMCID: PMC6121364 DOI: 10.3390/ijms19082227] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/19/2018] [Accepted: 07/23/2018] [Indexed: 12/12/2022] Open
Abstract
Cell contacts exhibit a considerable influence on tissue physiology and homeostasis by controlling paracellular and intercellular transport processes, as well as by affecting signaling pathways. Since they maintain cell polarity, they play an important role in cell plasticity. The knowledge about the junctional protein families and their interactions has increased considerably during recent years. In contrast to most other tissues, the endometrium undergoes extensive physiological changes and reveals an extraordinary plasticity due to its crucial role in the establishment and maintenance of pregnancy. These complex changes are accompanied by changes in direct cell–cell contacts to meet the various requirements in the respective developmental stage. Impairment of this sophisticated differentiation process may lead to failure of implantation and embryo development and may be involved in the pathogenesis of endometrial diseases. In this article, we focus on the knowledge about the distribution and regulation of the different junctional proteins in the endometrium during cycling and pregnancy, as well as in pathologic conditions such as endometriosis and cancer. Decoding these sophisticated interactions should improve our understanding of endometrial physiology as well as of the mechanisms involved in pathological conditions.
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AlFindee MN, Subedi YP, Fiori MC, Krishnan S, Kjellgren A, Altenberg GA, Chang CWT. Inhibition of Connexin Hemichannels by New Amphiphilic Aminoglycosides without Antibiotic Activity. ACS Med Chem Lett 2018; 9:697-701. [PMID: 30034603 DOI: 10.1021/acsmedchemlett.8b00158] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/19/2018] [Indexed: 12/11/2022] Open
Abstract
Connexins hemichannels (HCs) from adjacent cells form gap junctional channels that mediate cell-to-cell communication. Abnormal opening of "free" undocked HCs can produce cell damage and participate in the mechanism of disorders such as cardiac infarct, stroke, deafness, skin diseases, and cataracts. Therefore, inhibitors of connexin HCs have great pharmacological potential. Antibiotic aminoglycosides (AGs) have been recently identified as connexin HC inhibitors, but their antibiotic effect is an issue for the treatment of disorders where infections do not play a role. Herein, we synthesized and tested several amphiphilic AGs without antibiotic effect for their inhibition against connexin HCs, using a newly developed cell-based bacterial growth complementation assay. Several leads with superior potency than the parent compound, kanamycin A, were identified. Unlike traditional AGs, these amphiphilic AGs are not bactericidal and are not toxic to mammalian cells, making them better than traditional AGs as HC inhibitors for clinical use and other applications.
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Affiliation(s)
- Madher N. AlFindee
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322-0300, United States
- Department of Pharmaceutical Chemistry, College of Pharmacy, University of Basra, Basra, Iraq
| | - Yagya P. Subedi
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322-0300, United States
| | - Mariana C. Fiori
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430-6551, United States
| | - Srinivasan Krishnan
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430-6551, United States
| | - Abbey Kjellgren
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430-6551, United States
- Honors College, McClellan Hall, Box 41017, Texas Tech University, Lubbock, Texas 79409-1017, United States
| | - Guillermo A. Altenberg
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430-6551, United States
| | - Cheng-Wei T. Chang
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322-0300, United States
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March JT, Golshirazi G, Cernisova V, Carr H, Leong Y, Lu-Nguyen N, Popplewell LJ. Targeting TGFβ Signaling to Address Fibrosis Using Antisense Oligonucleotides. Biomedicines 2018; 6:biomedicines6030074. [PMID: 29941814 PMCID: PMC6164894 DOI: 10.3390/biomedicines6030074] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/13/2018] [Accepted: 06/14/2018] [Indexed: 12/29/2022] Open
Abstract
Fibrosis results from the excessive accumulation of extracellular matrix in chronically injured tissue. The fibrotic process is governed by crosstalk between many signaling pathways. The search for an effective treatment is further complicated by the fact that there is a degree of tissue-specificity in the pathways involved, although the process is not completely understood for all tissues. A plethora of drugs have shown promise in pre-clinical models, which is not always borne out translationally in clinical trial. With the recent approvals of two antisense oligonucleotides for the treatment of the genetic diseases Duchenne muscular dystrophy and spinal muscular atrophy, we explore here the potential of antisense oligonucleotides to knockdown the expression of pro-fibrotic proteins. We give an overview of the generalized fibrotic process, concentrating on key players and highlight where antisense oligonucleotides have been used effectively in cellular and animal models of different fibrotic conditions. Consideration is given to the advantages antisense oligonucleotides would have as an anti-fibrotic therapy alongside factors that would need to be addressed to improve efficacy. A prospective outlook for the development of antisense oligonucleotides to target fibrosis is outlined.
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Affiliation(s)
- James T March
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Golnoush Golshirazi
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Viktorija Cernisova
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Heidi Carr
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Yee Leong
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Ngoc Lu-Nguyen
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Linda J Popplewell
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
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Function of Connexins in the Interaction between Glial and Vascular Cells in the Central Nervous System and Related Neurological Diseases. Neural Plast 2018; 2018:6323901. [PMID: 29983707 PMCID: PMC6015683 DOI: 10.1155/2018/6323901] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/06/2018] [Accepted: 05/14/2018] [Indexed: 02/05/2023] Open
Abstract
Neuronal signaling together with synapse activity in the central nervous system requires a precisely regulated microenvironment. Recently, the blood-brain barrier is considered as a “neuro-glia-vascular unit,” a structural and functional compound composed of capillary endothelial cells, glial cells, pericytes, and neurons, which plays a pivotal role in maintaining the balance of the microenvironment in and out of the brain. Tight junctions and adherens junctions, which function as barriers of the blood-brain barrier, are two well-known kinds in the endothelial cell junctions. In this review, we focus on the less-concerned contribution of gap junction proteins, connexins in blood-brain barrier integrity under physio-/pathology conditions. In the neuro-glia-vascular unit, connexins are expressed in the capillary endothelial cells and prominent in astrocyte endfeet around and associated with maturation and function of the blood-brain barrier through a unique signaling pathway and an interaction with tight junction proteins. Connexin hemichannels and connexin gap junction channels contribute to the physiological or pathological progress of the blood-brain barrier; in addition, the interaction with other cell-cell-adhesive proteins is also associated with the maintenance of the blood-brain barrier. Lastly, we explore the connexins and connexin channels involved in the blood-brain barrier in neurological diseases and any programme for drug discovery or delivery to target or avoid the blood-brain barrier.
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62
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Ion homeostasis and ion channels in NLRP3 inflammasome activation and regulation. Curr Opin Immunol 2018; 52:8-17. [DOI: 10.1016/j.coi.2018.03.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 03/05/2018] [Indexed: 12/24/2022]
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Noureldin M, Chen H, Bai D. Functional Characterization of Novel Atrial Fibrillation-Linked GJA5 (Cx40) Mutants. Int J Mol Sci 2018; 19:E977. [PMID: 29587382 PMCID: PMC5979441 DOI: 10.3390/ijms19040977] [Citation(s) in RCA: 18] [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: 02/23/2018] [Revised: 03/16/2018] [Accepted: 03/21/2018] [Indexed: 12/18/2022] Open
Abstract
Atrial fibrillation (AF) is the most common form of cardiac arrhythmia. Recently, four novel heterozygous Cx40 mutations-K107R, L223M, Q236H, and I257L-were identified in 4 of 310 unrelated AF patients and a followup genetic analysis of the mutant carriers' families showed that the mutants were present in all the affected members. To study possible alterations associated with these Cx40 mutants, including their cellular localization and gap junction (GJ) function, we expressed GFP-tagged and untagged mutants in connexin-deficient model cells. All four Cx40 mutants showed clustered localization at cell-cell junctions similar to that observed of wildtype Cx40. However, cell pairs expressing Cx40 Q236H, but not the other individual mutants, displayed a significantly lower GJ coupling conductance (Gj) than wildtype Cx40. Similarly, co-expression of Cx40 Q236H with Cx43 resulted in a significantly lower Gj. Transjunctional voltage-dependent gating (Vj gating) properties were also altered in the GJs formed by Q236H. Reduced GJ function and altered Vj gating may play a role in promoting the Q236H carriers to AF.
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Affiliation(s)
- Mahmoud Noureldin
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, N6A 5C1 Canada.
| | - Honghong Chen
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, N6A 5C1 Canada.
| | - Donglin Bai
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, N6A 5C1 Canada.
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64
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Feugang JM, Liao SF, Willard ST, Ryan PL. In-depth proteomic analysis of boar spermatozoa through shotgun and gel-based methods. BMC Genomics 2018; 19:62. [PMID: 29347914 PMCID: PMC5774113 DOI: 10.1186/s12864-018-4442-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 01/10/2018] [Indexed: 01/14/2023] Open
Abstract
Background Mature spermatozoa contain numerous epididymal and seminal plasma proteins, which full identification through high-throughput technologies may allow for a better understanding of the sperm biology. Therefore, we conducted a global proteomic analysis of boar spermatozoa through shotgun and gel-based methodologies. Results The total proteins were extracted from mature spermatozoa and subjecsted to proteome analyses. Functional analyses of gene ontology representations and pathway enrichments were conducted on the shotgun dataset, followed by immunology and gene expression validations. Shotgun and gel-based approaches allowed the detection of 2728 proteins and 2123 spots, respectively. Approximately 38% and 59% of total proteins were respectively fully and partially annotated, and 3% were unknown. Gene ontology analysis indicated high proportions of proteins associated with intracellular and cytoplasm localizations, protein and nucleic acid binding, hydrolase and transferase activities, and cellular, metabolic, and regulation of biological processes. Proteins associated with phosphorylation processes and mitochondrial membranes, nucleic acid binding, and phosphate and phosphorous metabolics represented 77% of the dataset. Pathways associated with oxidative phosphorylation, citrate cycle, and extra-cellular matrix-receptor interaction were significantly enriched. Protein complex, intracellular organelle, cytoskeletal parts, fertilization and reproduction, and gap junction pathway were significantly enriched within the top 116 highly abundant proteins. Nine randomly selected protein candidates were confirmed with gel-based identification, immunofluorescence detection, and mRNA expression. Conclusions This study offers an in-depth proteomic mapping of mature boar spermatozoa that will enable comparative and discovery research for the improvement of male fertility. Electronic supplementary material The online version of this article (10.1186/s12864-018-4442-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jean M Feugang
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762, USA.
| | - Shengfa F Liao
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762, USA
| | - Scott T Willard
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762, USA.,Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS, 39762, USA
| | - Peter L Ryan
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762, USA.,Department of Pathobiology and Population Medicine, Mississippi State University, Mississippi State, MS, 39762, USA
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Greer K, Chen J, Brickler T, Gourdie R, Theus MH. Modulation of gap junction-associated Cx43 in neural stem/progenitor cells following traumatic brain injury. Brain Res Bull 2017; 134:38-46. [PMID: 28648814 PMCID: PMC5597487 DOI: 10.1016/j.brainresbull.2017.06.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/12/2017] [Accepted: 06/20/2017] [Indexed: 12/17/2022]
Abstract
Restoration of learning and memory deficits following traumatic brain injury (TBI) is attributed, in part, to enhanced neural stem/progenitor cell (NSPCs) function. Recent findings suggest gap junction (GJ)-associated connexin 43 (Cx43) plays a key role in the cell cycle regulation and function of NSPCs and is modulated following TBI. Here, we demonstrate that Cx43 is up-regulated in the dentate gyrus following TBI and is expressed on vimentin-positive cells in the subgranular zone. To test the role of Cx43 on NSPCs, we exposed primary cultures to the α-connexin Carboxyl Terminal (αCT1) peptide which selectively modulates GJ-associated Cx43. Treatment with αCT1 substantially reduced proliferation and increased caspase 3/7 expression on NSPCs in a dose-dependent manner. αCT1 exposure also reduced overall expression of Cx43 and phospho (p)-Serine368. These findings demonstrate that Cx43 positively regulates adult NPSCs; the modulation of which may influence changes in the dentate gyrus following TBI.
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Affiliation(s)
- Kisha Greer
- The Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, 215 Duck Pond Drive, Blacksburg, VA 24061, USA
| | - Jiang Chen
- The Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, 215 Duck Pond Drive, Blacksburg, VA 24061, USA
| | - Thomas Brickler
- The Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, 215 Duck Pond Drive, Blacksburg, VA 24061, USA
| | - Robert Gourdie
- Virgnia Tech Carillion Research Institute, College of Medicine, 2 Riverside Circle, Roanoke, VA 24016, USA
| | - Michelle H Theus
- The Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, 215 Duck Pond Drive, Blacksburg, VA 24061, USA.
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Aamodt KI, Powers AC. Signals in the pancreatic islet microenvironment influence β-cell proliferation. Diabetes Obes Metab 2017; 19 Suppl 1:124-136. [PMID: 28880471 PMCID: PMC5679109 DOI: 10.1111/dom.13031] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/22/2017] [Accepted: 06/01/2017] [Indexed: 12/31/2022]
Abstract
The progressive loss of pancreatic β-cell mass that occurs in both type 1 and type 2 diabetes is a primary factor driving efforts to identify strategies for effectively increasing, enhancing or restoring β-cell mass. While factors that seem to influence β-cell proliferation in specific contexts have been described, reliable stimulation of human β-cell proliferation has remained a challenge. Importantly, β-cells exist in the context of a complex, integrated pancreatic islet microenvironment where they interact with other endocrine cells, vascular endothelial cells, extracellular matrix, neuronal projections and islet macrophages. This review highlights different components of the pancreatic microenvironment, and reviews what is known about how signaling that occurs between β-cells and these other components influences β-cell proliferation. Future efforts to further define the role of the pancreatic islet microenvironment on β-cell proliferation may lead to the development of successful approaches to increase or restore β-cell mass in diabetes.
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Affiliation(s)
- Kristie I. Aamodt
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alvin C. Powers
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- VA Tennessee Valley Healthcare System, Nashville, TN, USA
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67
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Bai D, Yue B, Aoyama H. Crucial motifs and residues in the extracellular loops influence the formation and specificity of connexin docking. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:9-21. [PMID: 28693896 DOI: 10.1016/j.bbamem.2017.07.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/25/2017] [Accepted: 07/03/2017] [Indexed: 12/19/2022]
Abstract
Most of the early studies on gap junction (GJ) channel function and docking compatibility were on rodent connexins, while recent research on GJ channels gradually shifted from rodent to human connexins largely due to the fact that mutations in many human connexin genes are found to associate with inherited human diseases. The studies on human connexins have revealed some key differences from those found in rodents, calling for a comprehensive characterization of human GJ channels. Functional studies revealed that docking and formation of functional GJ channels between two hemichannels are possible only between docking-compatible connexins. Two groups of docking-compatible rodent connexins have been identified. Compatibility is believed to be due to their amino acid residue differences at the extracellular loop domains (E1 and E2). Sequence alignment of the E1 and E2 domains of all connexins known to make GJs revealed that they are highly conserved and show high sequence identity with human Cx26, which is the only connexin with near atomic resolution GJ structure. We hypothesize that different connexins have a similar structure as that of Cx26 at the E1 and E2 domains and use the corresponding residues in their E1 and E2 domains for docking. Based on the Cx26 GJ structure and sequence analysis of well-studied connexins, we propose that the E1-E1 docking interactions are staggered with each E1 interacting with two E1s on the docked connexon. The putative E1 docking residues are conserved in both docking-compatible and -incompatible connexins, indicating that E1 does not likely serve a role in docking compatibility. However, in the case of E2-E2 docking interactions, the putative docking residues are only conserved within the docking-compatible connexins, suggesting the E2 is likely to serve the function of docking compatibility. Docking compatibility studies on human connexins have attracted a lot of attention due to the fact that putative docking residues are mutational hotspots for several connexin-linked human diseases. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Donglin Bai
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada.
| | - Benny Yue
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Hiroshi Aoyama
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
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Abstract
Myocardial injury, mechanical stress, neurohormonal activation, inflammation, and/or aging all lead to cardiac remodeling, which is responsible for cardiac dysfunction and arrhythmogenesis. Of the key histological components of cardiac remodeling, fibrosis either in the form of interstitial, patchy, or dense scars, constitutes a key histological substrate of arrhythmias. Here we discuss current research findings focusing on the role of fibrosis, in arrhythmogenesis. Numerous studies have convincingly shown that patchy or interstitial fibrosis interferes with myocardial electrophysiology by slowing down action potential propagation, initiating reentry, promoting after-depolarizations, and increasing ectopic automaticity. Meanwhile, there has been increasing appreciation of direct involvement of myofibroblasts, the activated form of fibroblasts, in arrhythmogenesis. Myofibroblasts undergo phenotypic changes with expression of gap-junctions and ion channels thereby forming direct electrical coupling with cardiomyocytes, which potentially results in profound disturbances of electrophysiology. There is strong evidence that systemic and regional inflammatory processes contribute to fibrogenesis (i.e., structural remodeling) and dysfunction of ion channels and Ca2+ homeostasis (i.e., electrical remodeling). Recognizing the pivotal role of fibrosis in the arrhythmogenesis has promoted clinical research on characterizing fibrosis by means of cardiac imaging or fibrosis biomarkers for clinical stratification of patients at higher risk of lethal arrhythmia, as well as preclinical research on the development of antifibrotic therapies. At the end of this review, we discuss remaining key questions in this area and propose new research approaches. © 2017 American Physiological Society. Compr Physiol 7:1009-1049, 2017.
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Affiliation(s)
- My-Nhan Nguyen
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Central Clinical School, Monash University, Melbourne, Australia
| | - Helen Kiriazis
- Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Xiao-Ming Gao
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Central Clinical School, Monash University, Melbourne, Australia
| | - Xiao-Jun Du
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Central Clinical School, Monash University, Melbourne, Australia
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69
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Multiple and complex influences of connexins and pannexins on cell death. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017. [PMID: 28625689 DOI: 10.1016/j.bbamem.2017.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cell death is a fundamental process for organogenesis, immunity and cell renewal. During the last decades a broad range of molecular tools were identified as important players for several different cell death pathways (apoptosis, pyroptosis, necrosis, autosis…). Aside from these direct regulators of cell death programs, several lines of evidence proposed connexins and pannexins as potent effectors of cell death. In the present review we discussed the potential roles played by connexins, pannexins and innexins in the different cell death programs at different scales from gap junction intercellular communication to protein-protein interactions. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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70
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Vicario N, Calabrese G, Zappalà A, Parenti C, Forte S, Graziano ACE, Vanella L, Pellitteri R, Cardile V, Parenti R. Inhibition of Cx43 mediates protective effects on hypoxic/reoxygenated human neuroblastoma cells. J Cell Mol Med 2017; 21:2563-2572. [PMID: 28488330 PMCID: PMC5618696 DOI: 10.1111/jcmm.13177] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 02/28/2017] [Indexed: 12/18/2022] Open
Abstract
Olfactory ensheathing cells (OECs), a special population of glial cells, are able to synthesise several trophic factors exerting a neuroprotective action and promoting growth and functional recovery in both in vitro and in vivo models. In the present work, we investigated the neuroprotective effects of OEC-conditioned medium (OEC-CM) on two different human neuron-like cell lines, SH-SY5Y and SK-N-SH (neuroblastoma cell lines), under normoxic and hypoxic conditions. In addition, we also focused our attention on the role of connexins (Cxs) in the neuroprotective processes. Our results confirmed OEC-CM mediated neuroprotection as shown by cell adherence, proliferation and cellular viability analyses. Reduced connexin 43 (Cx43) levels in OEC-CM compared to unconditioned cells in hypoxic conditions prompted us to investigate the role of Cx43-Gap junctions (GJs) and Cx43-hemichannels (HCs) in hypoxic/reoxygenation injury using carbenoxolone (non-selective GJ inhibitor), ioxynil octanoato (selective Cx43-GJ inhibitor) and Gap19 (selective Cx43-HC inhibitor). We found that Cx43-GJ and Cx43-HC inhibitors are able to protect SH-SY5Y and allow to these cultures to overcome the injury. Our findings support the hypothesis that both OEC-CM and the inhibition of Cx43-GJs and Cx43-HCs offer a neuroprotective effect by reducing Cx43-mediated cell-to-cell and cell-to-extracellular environment communications.
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Affiliation(s)
- Nunzio Vicario
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
| | - Giovanna Calabrese
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
| | - Agata Zappalà
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
| | - Carmela Parenti
- Department of Drug Sciences, University of Catania, Catania, Italy
| | | | | | - Luca Vanella
- Department of Drug Sciences, University of Catania, Catania, Italy
| | - Rosalia Pellitteri
- Institute Neurological Sciences, National Research Council, Catania, Italy
| | - Venera Cardile
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
| | - Rosalba Parenti
- Department of Biomedical and Biotechnological Sciences, Physiology Section, University of Catania, Catania, Italy
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71
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Srinivas M, Verselis VK, White TW. Human diseases associated with connexin mutations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:192-201. [PMID: 28457858 DOI: 10.1016/j.bbamem.2017.04.024] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 04/20/2017] [Accepted: 04/25/2017] [Indexed: 01/11/2023]
Abstract
Gap junctions and hemichannels comprised of connexins impact many cellular processes. Significant advances in our understanding of the functional role of these channels have been made by the identification of a host of genetic diseases caused by connexin mutations. Prominent features of connexin disorders are the inability of other connexins expressed in the same cell type to compensate for the mutated one, and the ability of connexin mutants to dominantly influence the activity of other wild-type connexins. Functional studies have begun to identify some of the underlying mechanisms whereby connexin channel mutation contributes to the disease state. Detailed mechanistic understanding of these functional differences will help to facilitate new pathophysiology driven therapies for the diverse array of connexin genetic disorders. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Miduturu Srinivas
- Department of Biological and Vision Sciences, SUNY College of Optometry, New York, NY 10036, USA
| | - Vytas K Verselis
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Thomas W White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, USA.
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72
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Giuliani AL, Sarti AC, Falzoni S, Di Virgilio F. The P2X7 Receptor-Interleukin-1 Liaison. Front Pharmacol 2017; 8:123. [PMID: 28360855 PMCID: PMC5353276 DOI: 10.3389/fphar.2017.00123] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 02/28/2017] [Indexed: 12/20/2022] Open
Abstract
Interleukin-1β (IL-1β) plays a central role in stimulation of innate immune system and inflammation and in several chronic inflammatory diseases. These include rare hereditary conditions, e.g., auto-inflammatory syndromes, as well as common pathologies, such as type II diabetes, gout and atherosclerosis. A better understanding of IL-1β synthesis and release is particularly relevant for the design of novel anti-inflammatory drugs. One of the molecules mainly involved in IL-1β maturation is the P2X7 receptor (P2X7R), an ATP-gated ion channel that chiefly acts through the recruitment of the NLRP3 inflammasome-caspase-1 complex. In this review, we will summarize evidence supporting the key role of the P2X7R in IL-1β production, with special emphasis on the mechanism of release, a process that is still a matter of controversy. Four different models have been proposed: (i) exocytosis via secretory lysosomes, (ii) microvesicles shedding from plasma membrane, (iii) release of exosomes, and (iv) passive efflux across a leaky plasma membrane during pyroptotic cell death. All these models involve the P2X7R.
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Affiliation(s)
- Anna Lisa Giuliani
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara Ferrara, Italy
| | - Alba C Sarti
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara Ferrara, Italy
| | - Simonetta Falzoni
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara Ferrara, Italy
| | - Francesco Di Virgilio
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara Ferrara, Italy
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Abstract
Being critical mediators of liver homeostasis, connexins and their channels are frequently involved in liver toxicity. In the current paper, specific attention is paid to actions of hepatotoxic drugs on these communicative structures. In a first part, an overview is provided on the structural, regulatory and functional properties of connexin-based channels in the liver. In the second part, documented effects of acetaminophen, hypolipidemic drugs, phenobarbital and methapyriline on connexin signaling are discussed. Furthermore, the relevance of this subject for the fields of clinical and in vitro toxicology is demonstrated. Relevance for patients: The role of connexin signaling in drug-induced hepatotoxicity may be of high clinical relevance, as it offers perspectives for the therapeutic treatment of such insults by interfering with connexin channel opening.
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Affiliation(s)
- Michaël Maes
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
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74
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Begandt D, Good ME, Keller AS, DeLalio LJ, Rowley C, Isakson BE, Figueroa XF. Pannexin channel and connexin hemichannel expression in vascular function and inflammation. BMC Cell Biol 2017; 18:2. [PMID: 28124621 PMCID: PMC5267334 DOI: 10.1186/s12860-016-0119-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Control of blood flow distribution and tissue homeostasis depend on the tight regulation of and coordination between the microvascular network and circulating blood cells. Channels formed by connexins or pannexins that connect the intra- and extracellular compartments allow the release of paracrine signals, such as ATP and prostaglandins, and thus play a central role in achieving fine regulation and coordination of vascular function. This review focuses on vascular connexin hemichannels and pannexin channels. We review their expression pattern within the arterial and venous system with a special emphasis on how post-translational modifications by phosphorylation and S-nitrosylation of these channels modulate their function and contribute to vascular homeostasis. Furthermore, we highlight the contribution of these channels in smooth muscle cells and endothelial cells in the regulation of vasomotor tone as well as how these channels in endothelial cells regulate inflammatory responses such as during ischemic and hypoxic conditions. In addition, this review will touch on recent evidence implicating a role for these proteins in regulating red blood cell and platelet function.
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Affiliation(s)
- Daniela Begandt
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Miranda E Good
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Alex S Keller
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Leon J DeLalio
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Carol Rowley
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Brant E Isakson
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.,Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Xavier F Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
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75
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Bian B, Yu XF, Wang GQ, Teng TM. Role of miRNA-1 in regulating connexin 43 in ischemia-reperfusion heart injury: a rat model. Cardiovasc Pathol 2017; 27:37-42. [PMID: 28081514 DOI: 10.1016/j.carpath.2016.12.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 12/08/2016] [Accepted: 12/30/2016] [Indexed: 11/25/2022] Open
Abstract
MiRNA-1 may participate in regulating ischemia-reperfusion injury (IRI) by affecting the expression and distribution of connexin 43 (Cx43). The aim of this study is to investigate miR-1 expression and its potential role in regulating Cx43 during ischemic postconditioning (IPOST) in a rat model. Fifty-five Wistar male rats were randomly divided into five groups: N, IR, IPOST, agomir-1, and antagomir-1 group. The hearts were perfused with the Langendorff system. The reperfusion arrhythmia (RA) and myocardial infarct size were observed and recorded. The miRNA-1 expression and the Cx43 expression and distribution were assessed by RT-PCR, immunoblotting, and immunohistochemistry. First, the RA score in the IR group was higher than that in the control group, whereas there was no difference between the IPOST and antagomir-1 groups. Second, the myocardial infarct size was larger in the agomir-1 than in the IPOST group; there was no difference between the antagomir-1 and the IPOST group. Third, the miRNA-1 expression increased by 78% in the agomir-1 group but decreased by 32% in the antagomir-1 group compared with the IPOST group. Fourth, compared with the Control group, the Cx43 expression in the IR group decreased, the Cx43 expression decreased in the agomir-1 group compared with the IPOST group. Fifth, the distribution of Cx43 was irregular and disorganized in the IR and agomir-1 groups. In the IPOST and antagomir-1 groups, Cx43 was neatly distributed in the intercalated disk area. Our findings suggest that IPOST can inhibit the up-regulation of miRNA-1 induced by ischemia-reperfusion and that the down-regulation of miRNA-1 can prevent the decrease and redistribution of Cx43, which will protect the heart from IRI.
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Affiliation(s)
- Bo Bian
- Cardiology Department, Tianjin Medical University General Hospital, Tianjin, China
| | - Xue-Fang Yu
- Cardiology Department, Tianjin Medical University General Hospital, Tianjin, China.
| | - Guo-Qin Wang
- Cardiology Department, Tianjin Medical University General Hospital, Tianjin, China
| | - Tian-Ming Teng
- Cardiology Department, Tianjin Medical University General Hospital, Tianjin, China
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76
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Wong P, Tan T, Chan C, Laxton V, Chan YWF, Liu T, Wong WT, Tse G. The Role of Connexins in Wound Healing and Repair: Novel Therapeutic Approaches. Front Physiol 2016; 7:596. [PMID: 27999549 PMCID: PMC5138227 DOI: 10.3389/fphys.2016.00596] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/16/2016] [Indexed: 12/26/2022] Open
Abstract
Gap junctions are intercellular proteins responsible for mediating both electrical and biochemical coupling through the exchange of ions, second messengers and small metabolites. They consist of two connexons, with (one) connexon supplied by each cell. A connexon is a hexamer of connexins and currently more than 20 connexin isoforms have been described in the literature thus far. Connexins have a short half-life, and therefore gap junction remodeling constantly occurs with a high turnover rate. Post-translational modification, such as phosphorylation, can modify their channel activities. In this article, the roles of connexins in wound healing and repair are reviewed. Novel strategies for modulating the function or expression of connexins, such as the use of antisense technology, synthetic mimetic peptides and bioactive materials for the treatment of skin wounds, diabetic and pressure ulcers as well as cornea wounds, are considered.
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Affiliation(s)
- Pui Wong
- Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, University of Hong Kong Hong Kong, Hong Kong
| | - Teresa Tan
- Department of Surgery, Faculty of Medicine, Chinese University of Hong Kong Hong Kong, Hong Kong
| | - Catherine Chan
- Department of Surgery, Faculty of Medicine, Chinese University of Hong Kong Hong Kong, Hong Kong
| | - Victoria Laxton
- Intensive Care Department, Royal Brompton and Harefield NHS Foundation Trust London, UK
| | - Yin Wah Fiona Chan
- Department of Psychology, School of Biological Sciences, University of Cambridge Cambridge, UK
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University Tianjin, China
| | - Wing Tak Wong
- School of Life Sciences, Chinese University of Hong Kong Hong Kong, Hong Kong
| | - Gary Tse
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong KongHong Kong, Hong Kong; Faculty of Medicine, Li Ka Shing Institute of Health Sciences, Chinese University of Hong KongHong Kong, Hong Kong
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77
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Purinergic signalling in autoimmunity: A role for the P2X7R in systemic lupus erythematosus? Biomed J 2016; 39:326-338. [PMID: 27884379 PMCID: PMC6138817 DOI: 10.1016/j.bj.2016.08.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 07/29/2016] [Accepted: 08/08/2016] [Indexed: 12/11/2022] Open
Abstract
Purinergic signalling plays a crucial role in immunity and autoimmunity. Among purinergic receptors, the P2X7 receptor (P2X7R) has an undisputed role as it is expressed to high level by immune cells, triggers cytokine release and modulates immune cell differentiation. In this review, we focus on evidence supporting a possible role of the P2X7R in the pathogenesis of systemic lupus erythematosus (SLE).
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78
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Rodriguez-Paris J, Waldhaus J, Gordhandas JA, Pique L, Schrijver I. Comparative functional characterization of novel non-syndromic GJB2 gene variant p.Gly45Arg and lethal syndromic variant p.Gly45Glu. PeerJ 2016; 4:e2494. [PMID: 27761313 PMCID: PMC5068369 DOI: 10.7717/peerj.2494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 08/26/2016] [Indexed: 11/20/2022] Open
Abstract
We characterized a novel GJB2 missense variant, c.133G>A, p.Gly45Arg, and compared it with the only other variant at the same amino acid position of the connexin 26 protein (Cx26) reported to date: c.134G>A, p.Gly45Glu. Whereas both variants are associated with hearing loss and are dominantly inherited, p.Gly45Glu has been implicated in the rare fatal keratitis-ichthyosis-deafness (KID) syndrome, which results in cutaneous infections and septicemia with premature demise in the first year of life. In contrast, p.Gly45Arg appears to be non-syndromic. Subcellular localization experiments in transiently co-transfected HeLa cells demonstrated that Cx26-WT (wild-type) and p.Gly45Arg form gap junctions, whereas Cx26-WT with p.Gly45Glu protein does not. The substitution of a nonpolar amino acid glycine in wildtype Cx26 at position 45 with a negatively charged glutamic acid (acidic) has previously been shown to interfere with Ca2+ regulation of hemichannel gating and to inhibit the formation of gap junctions, resulting in cell death. The novel variant p.Gly45Arg, however, changes this glycine to a positively charged arginine (basic), resulting in the formation of dysfunctional gap junctions that selectively affect the permeation of negatively charged inositol 1,4,5-trisphosphate (IP3) and contribute to hearing loss. Cx26 p.Gly45Arg transfected cells, unlike cells transfected with p.Gly45Glu, thrived at physiologic Ca2+ concentrations, suggesting that Ca2+ regulation of hemichannel gating is unaffected in Cx26 p.Gly45Arg transfected cells. Thus, the two oppositely charged amino acids that replace the highly conserved uncharged glycine in p.Gly45Glu and p.Gly45Arg, respectively, produce strikingly different effects on the structure and function of the Cx26 protein.
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Affiliation(s)
- Juan Rodriguez-Paris
- Department of Pathology, Stanford University, Stanford, CA, United States of America
| | - Jörg Waldhaus
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, United States of America
| | - Jeenal A Gordhandas
- Department of Pathology, Stanford University, Stanford, CA, United States of America
| | - Lynn Pique
- Department of Pathology, Stanford University, Stanford, CA, United States of America
| | - Iris Schrijver
- Department of Pathology, Stanford University, Stanford, CA, United States of America.,Department of Pediatrics, Stanford University, Stanford, CA, United States of America
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79
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Cx26 knockout predisposes the mammary gland to primary mammary tumors in a DMBA-induced mouse model of breast cancer. Oncotarget 2016; 6:37185-99. [PMID: 26439696 PMCID: PMC4741923 DOI: 10.18632/oncotarget.5953] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 09/17/2015] [Indexed: 11/28/2022] Open
Abstract
Down-regulation of the gap junction protein connexin26 (Cx26) is an early event following breast cancer onset and has led to Cx26 being classically described as a tumor suppressor. Interestingly, mutations in theCx26 gene (GJB2) reduce or ablate Cx26 gap junction channel function and are the most common cause of genetic deafness. It is unknown if patients with loss-of-function GJB2 mutations have a greater susceptibility to breast tumorigenesis or aggressive breast cancer progression. To investigate these possibilities, 7, 12-dimethylbenz[α]anthracene (DMBA)-induced tumor development was evaluated in BLG-Cre; Cx26fl/fl mice expressing Cre under the β-Lactoglobulin promoter (Cre+) compared to Cx26fl/fl controlmice (Cre-) following pituitary isograft driven Cx26 knockout. A significantly increased number of DMBA-treated Cre+ mice developed primary mammary tumors, as well as developed multiple tumors, compared to Cre- mice. Primary tumors of Cre+ mice were of multiple histological subtypes and had similar palpable tumour onset and growth rate compared to tumors from Cre- mice. Lungs were evaluated for evidence of metastases revealing a similar percentage of lung metastases in Cre+ and Cre- mice. Together, our results suggest that loss of Cx26 predisposes the mammary gland to chemically induced mammary tumour formation which may have important implications to patients with GJB2 mutations.
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80
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Delamere NA, Mandal A, Shahidullah M. The Significance of TRPV4 Channels and Hemichannels in the Lens and Ciliary Epithelium. J Ocul Pharmacol Ther 2016; 32:504-508. [PMID: 27513167 DOI: 10.1089/jop.2016.0054] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To function normally, all cells must maintain ion homeostasis, establish a membrane potential, and regulate water content. These actions require active Na-K transport provided by Na,K-ATPase. The lens, however, is made up almost entirely of fiber cells that have little or no Na,K-ATPase activity. Lens ion and water homeostasis rely on Na,K-ATPase activity in a small number of cells at the periphery of epithelium monolayer. Therefore, the function of the epithelium must be integrated with the needs of the fiber mass. This suggests that a remote control mechanism may adjust Na,K-ATPase activity to match increases or decreases of ion leakage, which may occur a considerable distance away. Here, we review evidence that TRPV4 channels in the epithelium become activated when the lens is subjected to osmotic- or damage-induced swelling. This triggers a chain of events in the lens epithelium that opens connexin hemichannels, allowing ATP release that stimulates purinergic receptors, activates Src family tyrosine kinases, and increases Na,K-ATPase activity. Recent studies also revealed functional connexin hemichannels along with TRPV4 channels in nonpigmented ciliary epithelial (NPE) cells that secrete aqueous humor into the eye. Because TRPV4 channels are mechanosensitive, we speculate they might enable the NPE to respond to stimuli such as mechanical distortion associated with volume homeostasis during fluid transfer across the ciliary epithelium or changes in intraocular pressure.
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Affiliation(s)
| | - Amritlal Mandal
- Department of Physiology, University of Arizona , Tucson, Arizona
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81
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Beckmann A, Schubert M, Hainz N, Haase A, Martin U, Tschernig T, Meier C. Ultrastructural demonstration of Cx43 gap junctions in induced pluripotent stem cells from human cord blood. Histochem Cell Biol 2016; 146:529-537. [PMID: 27456332 DOI: 10.1007/s00418-016-1469-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2016] [Indexed: 01/13/2023]
Abstract
Gap junction proteins are essential for direct intercellular communication but also influence cellular differentiation and migration. The expression of various connexin gap junction proteins has been demonstrated in embryonic stem cells, with Cx43 being the most intensely studied. As Cx43 is the most prominent gap junction protein in the heart, cardiomyocyte-differentiated stem cells have been studied intensely. To date, however, little is known about the expression and the subcellular distribution of Cx43 in undifferentiated stem cells or about the structural arrangement of channels. We, therefore, here investigate expression of Cx43 in undifferentiated human cord-blood-derived induced pluripotent stem cells (hCBiPS2). For this purpose, we carried out quantitative real-time PCR and immunohistochemistry. For analysis of Cx43 ultrastructure and protein assembly, we performed freeze-fracture replica immunogold labeling (FRIL). Cx43 expression was detected at mRNA and protein level in hCBIPS2 cells. For the first time, ultrastructural data are presented on gap junction morphology in induced pluripotent stem (iPS) cells from cord blood: Our FRIL and electron microscopical analysis revealed the occurrence of gap junction plaques in undifferentiated iPS cells. In addition, these gap junctions were shown to contain the gap junction protein Cx43.
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Affiliation(s)
- Anja Beckmann
- Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, 66421, Homburg/Saar, Germany
| | - Madline Schubert
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplant and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany.,REBIRTH-Cluster of Excellence, Hannover Medical School, 30625, Hannover, Germany
| | - Nadine Hainz
- Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, 66421, Homburg/Saar, Germany
| | - Alexandra Haase
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplant and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany.,REBIRTH-Cluster of Excellence, Hannover Medical School, 30625, Hannover, Germany
| | - Ulrich Martin
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplant and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany.,REBIRTH-Cluster of Excellence, Hannover Medical School, 30625, Hannover, Germany
| | - Thomas Tschernig
- Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, 66421, Homburg/Saar, Germany
| | - Carola Meier
- Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, 66421, Homburg/Saar, Germany.
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82
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Esseltine JL, Laird DW. Next-Generation Connexin and Pannexin Cell Biology. Trends Cell Biol 2016; 26:944-955. [PMID: 27339936 DOI: 10.1016/j.tcb.2016.06.003] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 01/17/2023]
Abstract
Connexins and pannexins are two families of large-pore channel forming proteins that are capable of passing small signaling molecules. While connexins serve the seminal task of direct gap junctional intercellular communication, pannexins are far less understood but function primarily as single membrane channels in autocrine and paracrine signaling. Advancements in connexin and pannexin biology in recent years has revealed that in addition to well-described classical functions at the plasma membrane, exciting new evidence suggests that connexins and pannexins participate in alternative pathways involving multiple intracellular compartments. Here we briefly highlight classical functions of connexins and pannexins but focus our attention mostly on the transformative findings that suggest that these channel-forming proteins may serve roles far beyond our current understandings.
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Affiliation(s)
- Jessica L Esseltine
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
| | - Dale W Laird
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.
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83
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Plotkin LI, Laird DW, Amedee J. Role of connexins and pannexins during ontogeny, regeneration, and pathologies of bone. BMC Cell Biol 2016; 17 Suppl 1:19. [PMID: 27230612 PMCID: PMC4896274 DOI: 10.1186/s12860-016-0088-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Electron micrographs revealed the presence of gap junctions in osteoblastic cells over 40 years ago. These intercellular channels formed from connexins are present in bone forming osteoblasts, bone resorbing osteoclasts, and osteocytes (mature osteoblasts embedded in the mineralized bone matrix). More recently, genetic and pharmacologic studies revealed the role of connexins, and in particular Cx43, in the differentiation and function of all bone types. Furthermore, mutations in the gene encoding Cx43 were found to be causally linked to oculodentodigital dysplasia, a condition that results in an abnormal skeleton. Pannexins, molecules with similar structure and single-membrane channel forming potential as connexins when organized as hemichannels, are also expressed in osteoblastic cells. The function of pannexins in bone and cartilage is beginning to be uncovered, but more research is needed to determine the role of pannexins in bone development, adult bone mass and skeletal homeostasis. We describe here the current knowledge on the role of connexins and pannexins on skeletal health and disease.
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Affiliation(s)
- Lilian I Plotkin
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA. .,Roudebush Veterans Administration Medical Center Indiana, Indianapolis, IN, 46202, USA.
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, N6A-5C1, Canada
| | - Joelle Amedee
- INSERM U1026, Tissue Bioengineering, Université Bordeaux, Bordeaux, F-33076, France
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84
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Iwai-Takekoshi L, Ramos A, Schaler A, Weinreb S, Blazeski R, Mason C. Retinal pigment epithelial integrity is compromised in the developing albino mouse retina. J Comp Neurol 2016; 524:3696-3716. [PMID: 27097562 DOI: 10.1002/cne.24025] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/15/2016] [Accepted: 04/18/2016] [Indexed: 12/22/2022]
Abstract
In the developing murine eye, melanin synthesis in the retinal pigment epithelium (RPE) coincides with neurogenesis of retinal ganglion cells (RGCs). Disruption of pigmentation in the albino RPE is associated with delayed neurogenesis in the ventrotemporal retina, the source of ipsilateral RGCs, and a reduced ipsilateral RGC projection. To begin to unravel how melanogenesis and the RPE regulate RGC neurogenesis and cell subpopulation specification, we compared the features of albino and pigmented mouse RPE cells during the period of RGC neurogenesis (embryonic day, E, 12.5 to 18.5) when the RPE is closely apposed to developing RGC precursors. At E12.5 and E15.5, although albino and pigmented RPE cells express RPE markers Otx2 and Mitf similarly, albino RPE cells are irregularly shaped and have fewer melanosomes compared with pigmented RPE cells. The adherens junction protein P-cadherin appears loosely distributed within the albino RPE cells rather than tightly localized on the cell membrane, as in pigmented RPE. Connexin 43 (gap junction protein) is expressed in pigmented and albino RPE cells at E13.5 but at E15.5 albino RPE cells have fewer small connexin 43 puncta, and a larger fraction of phosphorylated connexin 43 at serine 368. These results suggest that the lack of pigment in the RPE results in impaired RPE cell integrity and communication via gap junctions between RPE and neural retina during RGC neurogenesis. Our findings should pave the way for further investigation of the role of RPE in regulating RGC development toward achieving proper RGC axon decussation. J. Comp. Neurol. 524:3696-3716, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Lena Iwai-Takekoshi
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Anna Ramos
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Ari Schaler
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Samuel Weinreb
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Richard Blazeski
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Carol Mason
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA. .,Department of Neuroscience, College of Physicians and Surgeons, Columbia University, New York, New York, USA. .,Department of Ophthalmology, College of Physicians and Surgeons, Columbia University, New York, New York, USA.
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85
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Liu Y, Qiao C, Wei T, Zheng F, Guo S, Chen Q, Yan M, Zhou X. Mutant connexin 50 (S276F) inhibits channel and hemichannel functions inducing cataract. J Genet 2016; 94:221-9. [PMID: 26174669 DOI: 10.1007/s12041-015-0506-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This study was designed to detect the expression, detergent resistance, subcellular localization, and channel and hemichannel functions of mutant Cx50 to understand the forming mechanism for inducing congenital cataract by a novel mutation p.S276F in connexin 50 (Cx50) reported previously by us. HeLa and human lens epithelial (HLE) cells were transfected with wild-type Cx50 and mutant Cx50 (S276F). We examined the functional characteristics of mutant Cx50 (S276F) in comparison with those of wild-type Cx50 using immunoblot, confocal fluorescence microscopy, dye transfer analysis and dye uptake assay. The mutant and wild-type Cx50 were expressed in equal levels and could efficiently localize to the plasma membrane without transportation and assembly problems. Scrape loading dye transfer was significantly evident in cells transfected with wild-type Cx50 compared to those in cells transfected with mutant Cx50 and cotransfected with wild-type and mutant Cx50. The dye uptake was found to be significantly lower in cells transfected with mutant Cx50 than in cells transfected with wild- type Cx50 and cells cotransfected with wild-type and mutant Cx50. The transfected HeLa and HLE cell lines showed similar performance in all the experiments. These results indicated that the mutant Cx50 (S276F) might inhibit the function of gap junction channel in a dominant negative manner, but inhibit the hemichannel function in a recessive negative manner.
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Affiliation(s)
- Yuanyuan Liu
- Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, People's Republic of China.
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86
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Osteocytic connexin hemichannels suppress breast cancer growth and bone metastasis. Oncogene 2016; 35:5597-5607. [PMID: 27041582 PMCID: PMC5050050 DOI: 10.1038/onc.2016.101] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 01/13/2016] [Accepted: 01/25/2016] [Indexed: 12/15/2022]
Abstract
Although the skeleton is one of predominant sites for breast cancer metastasis, why breast cancer cells often become dormant after homing to bone is not well understood. Here, we reported an intrinsic self-defense mechanism of bone cells against breast cancer cells: a critical role of connexin (Cx) 43 hemichannels in osteocytes in the suppression of breast cancer bone metastasis. Cx43 hemichannels allow passage of small molecules between the intracellular and extracellular environments. The treatment of bisphosphonate drugs, either alendronate (ALN) or zoledronic acid (ZOL), opened Cx43 hemichannels in osteocytes. Conditioned media (CM) collected from MLO-Y4 osteocyte cells treated with bisphosphonates inhibited the anchorage-independent growth, migration and invasion of MDA-MB-231 human breast cancer cells and Py8119 mouse mammary carcinoma cells and this inhibitory effect was attenuated with Cx43(E2), a specific hemichannel blocking antibody. The opening of osteocytic Cx43 hemichannels by mechanical stimulation had similar inhibitory effects on breast cancer cells and this inhibition was attenuated by Cx43(E2) antibody as well. These inhibitory effects on cancer cells were mediated by ATP released from osteocyte Cx43 hemichannels. Furthermore, both Cx43 osteocyte-specific knockout mice and osteocyte-specific Δ130–136 transgenic mice with impaired Cx43 gap junctions and hemichannels showed significantly increased tumor growth and attenuated the inhibitory effect of ZOL. However, R76W transgenic mice with functional hemichannels but not gap junctions in osteocytes did not display a significant difference. Together, our studies establish the specific inhibitory role of osteocytic Cx43 hemichannels, and exploiting the activity of this channel could serve as a de novo therapeutic strategy.
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87
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Cellular uptake of lead in the blood-cerebrospinal fluid barrier: Novel roles of Connexin 43 hemichannel and its down-regulations via Erk phosphorylation. Toxicol Appl Pharmacol 2016; 297:1-11. [DOI: 10.1016/j.taap.2016.02.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 02/24/2016] [Accepted: 02/25/2016] [Indexed: 11/23/2022]
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88
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Connexin 43, breast cancer tumor suppressor: Missed connections? Cancer Lett 2016; 374:117-126. [DOI: 10.1016/j.canlet.2016.02.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 01/28/2016] [Accepted: 02/03/2016] [Indexed: 12/21/2022]
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89
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Connexin43 in retinal injury and disease. Prog Retin Eye Res 2016; 51:41-68. [DOI: 10.1016/j.preteyeres.2015.09.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/25/2015] [Accepted: 09/27/2015] [Indexed: 12/26/2022]
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90
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Cell communication across gap junctions: a historical perspective and current developments. Biochem Soc Trans 2016; 43:450-9. [PMID: 26009190 DOI: 10.1042/bst20150056] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Collaborative communication lies at the centre of multicellular life. Gap junctions (GJs) are surface membrane structures that allow direct communication between cells. They were discovered in the 1960s following the convergence of the detection of low-resistance electrical interactions between cells and anatomical studies of intercellular contact points. GJs purified from liver plasma membranes contained a 27 kDa protein constituent; it was later named Cx32 (connexin 32) after its full sequence was determined by recombinant technology. Identification of Cx43 in heart and later by a further GJ protein, Cx26 followed. Cxs have a tetraspan organization in the membrane and oligomerize during intracellular transit to the plasma membrane; these were shown to be hexameric hemichannels (connexons) that could interact end-to-end to generate GJs at areas of cell-to-cell contact. The structure of the GJ was confirmed and refined by a combination of biochemical and structural approaches. Progress continues towards obtaining higher atomic 3D resolution of the GJ channel. Today, there are 20 and 21 highly conserved members of the Cx family in the human and mouse genomes respectively. Model organisms such as Xenopus oocytes and zebra fish are increasingly used to relate structure to function. Proteins that form similar large pore membrane channels in cells called pannexins have also been identified in chordates. Innexins form GJs in prechordates; these two other proteins, although functionally similar, are very different in amino acid sequence to the Cxs. A time line tracing the historical progression of wide ranging research in GJ biology over 60 years is mapped out. The molecular basis of channel dysfunctions in disease is becoming evident and progress towards addressing Cx channel-dependent pathologies, especially in ischaemia and tissue repair, continues.
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91
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Nutrient Starvation Decreases Cx43 Levels and Limits Intercellular Communication in Primary Bovine Corneal Endothelial Cells. J Membr Biol 2016; 249:363-73. [PMID: 26873723 DOI: 10.1007/s00232-016-9874-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 01/22/2016] [Indexed: 12/11/2022]
Abstract
Connexin (Cx) proteins form large conductance channels which function as regulators of communication between neighboring cells via gap junctions and/or hemichannels. Intercellular communication is essential to coordinate cellular responses in tissues and organs, thereby fulfilling an essential role in the spreading of signaling, survival and death processes. Connexin 43 (Cx43), a major connexin isoform in brain and heart, is rapidly turned over. Recent studies implicated that autophagy, a lysosomal degradation pathway induced upon nutrient starvation, mediates connexins, including Cx43, degradation. Here, we examined the impact of nutrient starvation on endogenous Cx43-protein levels and endogenous Cx43-driven intercellular communication in primary bovine corneal endothelial cells (BCECs). Hank's Balanced Salt Solution (HBSS) was used as a starvation condition that induces autophagic flux without impacting the survival of the BCECs. Nutrient starvation of BCECs caused a rapid decline in Cx43-protein levels, both as gap junctions and as hemichannels. The time course of the decline in Cx43-protein levels coincided with the time course of the decline in intercellular communication, assessed as intercellular Ca(2+)-wave propagation in BCECs exposed to a single-cell mechanical stimulus. The decline in Cx43-protein levels, both as gap junctions and as hemichannels, could be prevented by the addition of bafilomycin A1, a lysosomal inhibitor, during the complete nutrient starvation period. Consistent with this, bafilomycin A1 significantly alleviated the decrease in intercellular Ca(2+)-wave propagation. This study further underpins the importance of autophagy as an important degradation pathway for Cx43 proteins during periods of nutrient deprivation, thereby impacting the ability of cells to perform intercellular communication.
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Riding A, Pullar CE. ATP Release and P2 Y Receptor Signaling are Essential for Keratinocyte Galvanotaxis. J Cell Physiol 2016; 231:181-91. [PMID: 26058714 DOI: 10.1002/jcp.25070] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 06/05/2015] [Indexed: 01/06/2023]
Abstract
Repair to damaged tissue requires directional cell migration to heal the wound. Immediately upon wounding an electrical guidance cue is created with the cathode of the electric field (EF) located at the center of the wound. Previous research has demonstrated directional migration of keratinocytes toward the cathode when an EF of physiological strength (100-150 mV/mm) is applied in vitro, but the "sensor" by which keratinocytes sense the EF remains elusive. Here we use a customized chamber design to facilitate the application of a direct current (DC) EF of physiological strength (100 mV/mm) to keratinocytes whilst pharmacologically modulating the activation of both connexin hemichannels and purinergic receptors to determine their role in EF-mediated directional keratinocyte migration, galvanotaxis. In addition, keratinocytes were exposed to DiSCAC2 (3) dye to visualize membrane potential changes within the cell upon exposure to the applied DC EF. Here we unveil ATP-medicated mechanisms that underpin the initiation of keratinocyte galvanotaxis. The application of a DC EF of 100 mV/mm releases ATP via hemichannels activating a subset of purinergic P2 Y receptors, locally, to initiate the directional migration of keratinocytes toward the cathode in vitro, the center of the wound in vivo. The delineation of the mechanisms underpinning galvanotaxis extends our understanding of this endogenous cue and will facilitate the optimization and wider use of EF devices for chronic wound treatment. J. Cell. Physiol. 230: 181-191, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Aimie Riding
- Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, UK
| | - Christine E Pullar
- Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, UK
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93
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Connexin channels in congenital skin disorders. Semin Cell Dev Biol 2016; 50:4-12. [PMID: 26775130 DOI: 10.1016/j.semcdb.2015.11.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 11/22/2022]
Abstract
Gap junctions and hemichannels comprised of connexins influence epidermal proliferation and differentiation. Significant advances in our understanding of the functional role of connexins in the skin have been made by studying the diseases caused by connexin mutations. Eleven clinically defined cutaneous disorders with an overlapping spectrum of phenotypes are caused by mutations in five different connexin genes, highlighting that disease presentation must be deciphered with an understanding of how connexin functions are affected. Increasing evidence suggests that the skin diseases produced by connexin mutations result from dominant gains of function. In palmoplantar keratoderma with deafness, the connexin 26 mutations transdominantly alter the function of wild-type connexin 43 and create leaky heteromeric hemichannels. In keratitis-ichthyosis-deafness syndrome, different connexin 26 mutations can either form dominant hemichannels with altered calcium regulation or increased calcium permeability, leading to clinical subtypes of this syndrome. It is only with detailed understanding of these subtle functional differences that we can hope to create successful pathophysiology driven therapies for the connexin skin disorders.
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94
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Pinet-Charvet C, Geller S, Desroziers E, Ottogalli M, Lomet D, Georgelin C, Tillet Y, Franceschini I, Vaudin P, Duittoz A. GnRH Episodic Secretion Is Altered by Pharmacological Blockade of Gap Junctions: Possible Involvement of Glial Cells. Endocrinology 2016; 157:304-22. [PMID: 26562259 DOI: 10.1210/en.2015-1437] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Episodic release of GnRH is essential for reproductive function. In vitro studies have established that this episodic release is an endogenous property of GnRH neurons and that GnRH secretory pulses are associated with synchronization of GnRH neuron activity. The cellular mechanisms by which GnRH neurons synchronize remain largely unknown. There is no clear evidence of physical coupling of GnRH neurons through gap junctions to explain episodic synchronization. However, coupling of glial cells through gap junctions has been shown to regulate neuron activity in their microenvironment. The present study investigated whether glial cell communication through gap junctions plays a role in GnRH neuron activity and secretion in the mouse. Our findings show that Glial Fibrillary Acidic Protein-expressing glial cells located in the median eminence in close vicinity to GnRH fibers expressed Gja1 encoding connexin-43. To study the impact of glial-gap junction coupling on GnRH neuron activity, an in vitro model of primary cultures from mouse embryo nasal placodes was used. In this model, GnRH neurons possess a glial microenvironment and were able to release GnRH in an episodic manner. Our findings show that in vitro glial cells forming the microenvironment of GnRH neurons expressed connexin-43 and displayed functional gap junctions. Pharmacological blockade of the gap junctions with 50 μM 18-α-glycyrrhetinic acid decreased GnRH secretion by reducing pulse frequency and amplitude, suppressed neuronal synchronization and drastically reduced spontaneous electrical activity, all these effects were reversed upon 18-α-glycyrrhetinic acid washout.
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Affiliation(s)
- Caroline Pinet-Charvet
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
| | - Sarah Geller
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
| | - Elodie Desroziers
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
| | - Monique Ottogalli
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
| | - Didier Lomet
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
| | - Christine Georgelin
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
| | - Yves Tillet
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
| | - Isabelle Franceschini
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
| | - Pascal Vaudin
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
| | - Anne Duittoz
- Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Institut National de la Recherche Agronomique (INRA); UMR7247 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Centre National de la Recherche Scientifique (CNRS); and Institut Français du Cheval et de l'Equitation (IFCE) (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37380 Nouzilly, France; Physiologie de la Reproduction et des Comportements (PRC) UMR7247 INRA CNRS IFCE (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.) and CNRS UMR7350 (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), Laboratoire de Mathématiques et Physiques Théoriques, Université François Rabelais, F-37041 Tours, France; Fédération Denis Poisson (C.G.), F-37000 Tours, France; Structure Fédérative de Recherche (SFR) FED4226 Neuro-Imagerie Fonctionnelle (C.P.-C., S.G., E.D., M.O., D.L., Y.T., I.F., P.V., A.D.), F-37044 Tours, France; and Université de Poitiers (C.P.-C.), Unité de Formation et de Recherche (UFR) Pharmacie, F-86000 Poitiers, France
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95
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Cell Signaling in Tenocytes: Response to Load and Ligands in Health and Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 920:79-95. [DOI: 10.1007/978-3-319-33943-6_7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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96
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Kim Y, Davidson JO, Gunn KC, Phillips AR, Green CR, Gunn AJ. Role of Hemichannels in CNS Inflammation and the Inflammasome Pathway. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2016; 104:1-37. [DOI: 10.1016/bs.apcsb.2015.12.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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97
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Pacheco-Costa R, Davis HM, Sorenson C, Hon MC, Hassan I, Reginato RD, Allen MR, Bellido T, Plotkin LI. Defective cancellous bone structure and abnormal response to PTH in cortical bone of mice lacking Cx43 cytoplasmic C-terminus domain. Bone 2015; 81:632-643. [PMID: 26409319 PMCID: PMC4640960 DOI: 10.1016/j.bone.2015.09.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 09/04/2015] [Accepted: 09/22/2015] [Indexed: 10/23/2022]
Abstract
Connexin 43 (Cx43) forms gap junction channels and hemichannels that allow the communication among osteocytes, osteoblasts, and osteoclasts. Cx43 carboxy-terminal (CT) domain regulates channel opening and intracellular signaling by acting as a scaffold for structural and signaling proteins. To determine the role of Cx43 CT domain in bone, mice in which one allele of full length Cx43 was replaced by a mutant lacking the CT domain (Cx43(ΔCT/fl)) were studied. Cx43(ΔCT/fl) mice exhibit lower cancellous bone volume but higher cortical thickness than Cx43(fl/fl) controls, indicating that the CT domain is involved in normal cancellous bone gain but opposes cortical bone acquisition. Further, Cx43(ΔCT) is able to exert the functions of full length osteocytic Cx43 on cortical bone geometry and mechanical properties, demonstrating that domains other than the CT are responsible for Cx43 function in cortical bone. In addition, parathyroid hormone (PTH) failed to increase endocortical bone formation or energy to failure, a mechanical property that indicates resistance to fracture, in cortical bone in Cx43(ΔCT) mice with or without osteocytic full length Cx43. On the other hand, bone mass and bone formation markers were increased by the hormone in all mouse models, regardless of whether full length or Cx43(ΔCT) were or not expressed. We conclude that Cx43 CT domain is involved in proper bone acquisition; and that Cx43 expression in osteocytes is dispensable for some but not all PTH anabolic actions.
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Affiliation(s)
- Rafael Pacheco-Costa
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Morphology & Genetics, Federal University of São Paulo School of Medicine, São Paulo, Brazil.
| | - Hannah M Davis
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Chad Sorenson
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Mary C Hon
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Iraj Hassan
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Rejane D Reginato
- Department of Morphology & Genetics, Federal University of São Paulo School of Medicine, São Paulo, Brazil.
| | - Matthew R Allen
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Teresita Bellido
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Div. Endocrinology, Dept. Internal Medicine, Indiana University School of Medicine, Indianapolis, IN, USA; Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.
| | - Lilian I Plotkin
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.
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98
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Yu F, Yan H, Nie W, Zhu J. Connexin43 knockdown in bone marrow‑derived dendritic cells by small interfering RNA leads to a diminished T-cell stimulation. Mol Med Rep 2015; 13:895-900. [PMID: 26648560 DOI: 10.3892/mmr.2015.4593] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 08/25/2015] [Indexed: 11/06/2022] Open
Abstract
Dendritic cells, the most powerful type of antigen‑presenting cells, have the unique ability to induce primary immune responses. Connexin43 expression is upregulated to increase gap junctions when immune cells are exposed to inflammatory factors. The present study applied small‑interfering RNA (siRNA) to decrease connexin43 expression. The results showed that silencing of connexin43 using siRNA resulted in arrest of bone marrow‑derived dendritic cell (BM‑DC) maturation as evidenced by reduced expression of major histocompatibility complex II, CD40, CD80 and CD86. Functionally, connexin43‑silenced BM‑DC showed a markedly decreased capability to induce T-cell stimulation. In conclusion, the present study demonstrated that antigens present on BM‑DCs can be suppressed by connexin43 knockdown in BM‑DCs. The present study therefore presented an effective method to modulate the immunology of BM‑DCs.
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Affiliation(s)
- Fuling Yu
- Cardiovascular Department, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
| | - Hui Yan
- Cardiovascular Department, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
| | - Wencheng Nie
- Cardiovascular Department, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
| | - Jianhua Zhu
- Cardiovascular Department, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
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Wang SP, Chen FY, Dong LX, Zhang YQ, Chen HY, Qiao K, Wang KJ. A novel innexin2 forming membrane hemichannel exhibits immune responses and cell apoptosis in Scylla paramamosain. FISH & SHELLFISH IMMUNOLOGY 2015; 47:485-499. [PMID: 26384843 DOI: 10.1016/j.fsi.2015.09.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 09/06/2015] [Accepted: 09/14/2015] [Indexed: 06/05/2023]
Abstract
Innexins are a class of transmembrane proteins that are important for embryonic development, morphogenesis and electrical synapse formation. In the present study, a novel innexin2 gene from Scylla paramamosain was named Sp-inx2 and characterized. The complete cDNA and genomic DNA sequences of Sp-inx2 were revealed. Sp-inx2 mRNA transcripts were distributed in various tissues of S. paramamosain and were most abundant in the hemocytes. The Sp-inx2 was significantly upregulated in hemocyte, gill and hepatopancreas tissues with the challenge of either Vibrio alginolyticus, Vibrio parahaemolyticus or lipopolysaccharides (LPSs) when analyzed at 3 and 6 h using quantitative real-time PCR, suggesting that it could activate an immune response against the challenge of LPSs or Vibrio species. Using the chemical inhibitors carbenoxolone and probenecid, the absorption of the fluorescent dye Lucifer yellow decreased in the primary cultured hemocytes of crabs, thus confirming that hemichannels composed of Sp-inx2 existed in the crab hemocytes. With LPS stimulation, the level of mRNA transcripts and protein expression of Sp-inx2 in the same cultured hemocytes gradually increased from 6 to 48 h, while the activity of hemichannels was down-regulated at 6 and 12 h, demonstrating that LPSs could modulate the absorption activity of hemichannels in addition to its upregulation of Sp-inx2 gene expression. Furthermore, the dye uptake rate in HeLa cells in which Sp-inx2 was ectopically expressed increased dramatically but the increase was significantly down-regulated with the addition of 50 μg mL(-1) LPS, suggesting that the LPS stimulation could effectively reduce the activity of hemichannels. Interestingly, with the ectopic expression of Sp-inx2 in HeLa and EPC cells, apoptosis spontaneously occurred in both cultured cell lines when detected using TUNEL assay. In summary, a new Sp-inx2 gene was first characterized in a marine animal S. paramamosain and it had a function associated with immune response and cell apoptosis.
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Affiliation(s)
- Shu-Ping Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University, Xiamen, Fujian, PR China
| | - Fang-Yi Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University, Xiamen, Fujian, PR China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen University, Xiamen, Fujian, PR China; Fujian Engineering Laboratory of Marine Bioproducts and Technology, Xiamen University, Xiamen, Fujian, PR China
| | - Li-Xia Dong
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University, Xiamen, Fujian, PR China
| | - Ya-Qun Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University, Xiamen, Fujian, PR China
| | - Hui-Yun Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University, Xiamen, Fujian, PR China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen University, Xiamen, Fujian, PR China; Fujian Engineering Laboratory of Marine Bioproducts and Technology, Xiamen University, Xiamen, Fujian, PR China
| | - Kun Qiao
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University, Xiamen, Fujian, PR China
| | - Ke-Jian Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University, Xiamen, Fujian, PR China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen University, Xiamen, Fujian, PR China; Fujian Engineering Laboratory of Marine Bioproducts and Technology, Xiamen University, Xiamen, Fujian, PR China.
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Sun P, Dong L, MacDonald AI, Akbari S, Edward M, Hodgins MB, Johnstone SR, Graham SV. HPV16 E6 Controls the Gap Junction Protein Cx43 in Cervical Tumour Cells. Viruses 2015; 7:5243-56. [PMID: 26445057 PMCID: PMC4632379 DOI: 10.3390/v7102871] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 09/24/2015] [Accepted: 09/30/2015] [Indexed: 12/16/2022] Open
Abstract
Human papillomavirus type 16 (HPV16) causes a range of cancers including cervical and head and neck cancers. HPV E6 oncoprotein binds the cell polarity regulator hDlg (human homologue of Drosophila Discs Large). Previously we showed in vitro, and now in vivo, that hDlg also binds Connexin 43 (Cx43), a major component of gap junctions that mediate intercellular transfer of small molecules. In HPV16-positive non-tumour cervical epithelial cells (W12G) Cx43 localised to the plasma membrane, while in W12T tumour cells derived from these, it relocated with hDlg into the cytoplasm. We now provide evidence that E6 regulates this cytoplasmic pool of Cx43. E6 siRNA depletion in W12T cells resulted in restoration of Cx43 and hDlg trafficking to the cell membrane. In C33a HPV-negative cervical tumour cells expressing HPV16 or 18 E6, Cx43 was located primarily in the cytoplasm, but mutation of the 18E6 C-terminal hDlg binding motif resulted in redistribution of Cx43 to the membrane. The data indicate for the first time that increased cytoplasmic E6 levels associated with malignant progression alter Cx43 trafficking and recycling to the membrane and the E6/hDlg interaction may be involved. This suggests a novel E6-associated mechanism for changes in Cx43 trafficking in cervical tumour cells.
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Affiliation(s)
- Peng Sun
- Feinberg School of Medicine, North Western University, Chicago, IL 60611, USA.
| | - Li Dong
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, Scotland, UK.
| | - Alasdair I MacDonald
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, Scotland, UK.
| | - Shahrzad Akbari
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, Scotland, UK.
| | - Michael Edward
- Dermatology, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TT, Scotland, UK.
| | - Malcolm B Hodgins
- Dermatology, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TT, Scotland, UK.
| | - Scott R Johnstone
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TT, Scotland, UK.
| | - Sheila V Graham
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, Scotland, UK.
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