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Chang CWT, Poudyal N, Verdugo DA, Peña F, Stehberg J, Retamal MA. KI04 an Aminoglycosides-Derived Molecule Acts as an Inhibitor of Human Connexin46 Hemichannels Expressed in HeLa Cells. Biomolecules 2023; 13:411. [PMID: 36979346 PMCID: PMC10046693 DOI: 10.3390/biom13030411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/12/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Connexins (Cxs) are proteins that help cells to communicate with the extracellular media and with the cytoplasm of neighboring cells. Despite their importance in several human physiological and pathological conditions, their pharmacology is very poor. In the last decade, some molecules derived from aminoglycosides have been developed as inhibitors of Cxs hemichannels. However, these studies have been performed in E. coli, which is a very simple model. Therefore, our main goal is to test whether these molecules have similar effects in mammalian cells. METHODS We transfected HeLa cells with the human Cx46tGFP and characterized the effect of a kanamycin-derived molecule (KI04) on Cx46 hemichannel activity by time-lapse recordings, changes in phosphorylation by Western blot, localization by epifluorescence, and possible binding sites by molecular dynamics (MD). RESULTS We observed that kanamycin and KI04 were the most potent inhibitors of Cx46 hemichannels among several aminoglycosides, presenting an IC50 close to 10 μM. The inhibitory effect was not associated with changes in Cx46 electrophoretic mobility or its intracellular localization. Interestingly, 5 mM DTT did not reverse KI04 inhibition, but the KI04 effect completely disappeared after washing out KI04 from the recording media. MD analysis revealed two putative binding sites of KI04 in the Cx46 hemichannel. RESULTS These results demonstrate that KI04 could be used as a Cx46 inhibitor and could help to develop future selective Cx46 inhibitors.
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Affiliation(s)
- Cheng-Wei T. Chang
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA
| | - Naveena Poudyal
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA
| | - Daniel A. Verdugo
- Laboratorio de Neurobiología, Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andres Bello, Santiago 7780272, Chile
| | - Francisca Peña
- Laboratorio de Neurobiología, Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andres Bello, Santiago 7780272, Chile
| | - Jimmy Stehberg
- Laboratorio de Neurobiología, Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andres Bello, Santiago 7780272, Chile
| | - Mauricio A. Retamal
- Center for Membrane Protein Research, Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7610496, Chile
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2
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Helkkula P, Hassan S, Saarentaus E, Vartiainen E, Ruotsalainen S, Leinonen JT, Palotie A, Karjalainen J, Kurki M, Ripatti S, Tukiainen T. Genome-wide association study of varicose veins identifies a protective missense variant in GJD3 enriched in the Finnish population. Commun Biol 2023; 6:71. [PMID: 36653477 PMCID: PMC9849365 DOI: 10.1038/s42003-022-04285-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 11/21/2022] [Indexed: 01/19/2023] Open
Abstract
Varicose veins is the most common manifestation of chronic venous disease that displays female-biased incidence. To identify protein-inactivating variants that could guide identification of drug target genes for varicose veins and genetic evidence for the disease prevalence difference between the sexes, we conducted a genome-wide association study of varicose veins in Finns using the FinnGen dataset with 17,027 cases and 190,028 controls. We identified 50 associated genetic loci (P < 5.0 × 10-8) of which 29 were novel including one near ERG with female-specificity (rs2836405-G, OR[95% CI] = 1.09[1.05-1.13], P = 3.1 × 10-8). These also include two X-chromosomal (ARHGAP6 and SRPX) and two autosomal novel loci (TGFB2 and GJD3) with protein-coding lead variants enriched above 56-fold in Finns over non-Finnish non-Estonian Europeans. A low-frequency missense variant in GJD3 (p.Pro59Thr) is exclusively associated with a lower risk for varicose veins (OR = 0.62 [0.55-0.70], P = 1.0 × 10-14) in a phenome-wide scan of the FinnGen data. The absence of observed pleiotropy and its membership of the connexin gene family underlines GJD3 as a potential connexin-modulating therapeutic strategy for varicose veins. Our results provide insights into varicose veins etiopathology and highlight the power of isolated populations, including Finns, to discover genetic variants that inform therapeutic development.
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Grants
- MC_PC_17228 Medical Research Council
- Academy of Finland (Suomen Akatemia)
- Sydäntutkimussäätiö (Finnish Foundation for Cardiovascular Research)
- Academy of Finland Center of Excellence in Complex Disease Genetics (Grant No 312062), Sigrid Juselius Foundation (S.Ri. and T.T.), University of Helsinki HiLIFE Fellow and Grand Challenge grants (S.Ri.), University of Helsinki three-year research project grant (T.T.), FIMM-EMBL PhD program doctoral funding (S.H.), Nylands Nation, University of Helsinki (P.H.) The FinnGen project is funded by two grants from Business Finland (HUS 4685/31/2016 and UH 4386/31/2016) and the following industry partners: AbbVie Inc., AstraZeneca UK Ltd, Biogen MA Inc., Bristol Myers Squibb (and Celgene Corporation & Celgene International II Sàrl), Genentech Inc., Merck Sharp & Dohme Corp, Pfizer Inc., GlaxoSmithKline Intellectual Property Development Ltd., Sanofi US Services Inc., Maze Therapeutics Inc., Janssen Biotech Inc, Novartis AG, and Boehringer Ingelheim. Following biobanks are acknowledged for delivering biobank samples to FinnGen: Auria Biobank (www.auria.fi/biopankki), THL Biobank (www.thl.fi/biobank), Helsinki Biobank (www.helsinginbiopankki.fi), Biobank Borealis of Northern Finland (https://www.ppshp.fi/Tutkimus-ja-opetus/Biopankki/Pages/Biobank-Borealis-briefly-in-English.aspx), Finnish Clinical Biobank Tampere (www.tays.fi/en-US/Research_and_development/Finnish_Clinical_Biobank_Tampere), Biobank of Eastern Finland (www.ita-suomenbiopankki.fi/en), Central Finland Biobank (www.ksshp.fi/fi-FI/Potilaalle/Biopankki), Finnish Red Cross Blood Service Biobank (www.veripalvelu.fi/verenluovutus/biopankkitoiminta) and Terveystalo Biobank (www.terveystalo.com/fi/Yritystietoa/Terveystalo-Biopankki/Biopankki/).
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Affiliation(s)
- Pyry Helkkula
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Shabbeer Hassan
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Elmo Saarentaus
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Emilia Vartiainen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Sanni Ruotsalainen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Jaakko T Leinonen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Aarno Palotie
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Juha Karjalainen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- Broad Institute of the Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA
| | - Mitja Kurki
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- Broad Institute of the Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA
| | - Samuli Ripatti
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- Broad Institute of the Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA
- Department of Public Health, Clinicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Taru Tukiainen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland.
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The Role of Connexin in Ophthalmic Neovascularization and the Interaction between Connexin and Proangiogenic Factors. J Ophthalmol 2022; 2022:8105229. [PMID: 35783340 PMCID: PMC9242797 DOI: 10.1155/2022/8105229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 06/11/2022] [Indexed: 12/02/2022] Open
Abstract
The formation of new blood vessels is an important physiological process that occurs during development. When the body is injured, new blood vessel formation helps the body recuperate by supplying more oxygen and nutrients. However, this mechanism can have a negative effect. In ophthalmologic diseases, such as corneal new blood vessels, neonatal vascular glaucoma, and diabetes retinopathy, the formation of new blood vessels has become a critical component in patient survival. Connexin is a protein that regulates the cellular and molecular material carried by cells. It has been demonstrated that it is widely expressed in vascular endothelial cells, where it forms a slit connection between adjacent cells to promote cell-cell communication via hemichannels, as well as substance exchange into intracellular environments. Numerous studies have demonstrated that connexin in vascular endothelial cells plays an important role in angiogenesis and vascular leakage. The purpose of this study was to investigate the effect between the angiogenesis-associated factor and the connexin. It also reveals the effect of connexin on ophthalmic neovascularization.
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4
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The Non-Linear Path from Gene Dysfunction to Genetic Disease: Lessons from the MICPCH Mouse Model. Cells 2022; 11:cells11071131. [PMID: 35406695 PMCID: PMC8997851 DOI: 10.3390/cells11071131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/09/2022] [Accepted: 03/24/2022] [Indexed: 11/17/2022] Open
Abstract
Most human disease manifests as a result of tissue pathology, due to an underlying disease process (pathogenesis), rather than the acute loss of specific molecular function(s). Successful therapeutic strategies thus may either target the correction of a specific molecular function or halt the disease process. For the vast majority of brain diseases, clear etiologic and pathogenic mechanisms are still elusive, impeding the discovery or design of effective disease-modifying drugs. The development of valid animal models and their proper characterization is thus critical for uncovering the molecular basis of the underlying pathobiological processes of brain disorders. MICPCH (microcephaly and pontocerebellar hypoplasia) is a monogenic condition that results from variants of an X-linked gene, CASK (calcium/calmodulin-dependent serine protein kinase). CASK variants are associated with a wide range of clinical presentations, from lethality and epileptic encephalopathies to intellectual disabilities, microcephaly, and autistic traits. We have examined CASK loss-of-function mutations in model organisms to simultaneously understand the pathogenesis of MICPCH and the molecular function/s of CASK. Our studies point to a highly complex relationship between the potential molecular function/s of CASK and the phenotypes observed in model organisms and humans. Here we discuss the implications of our observations from the pathogenesis of MICPCH as a cautionary narrative against oversimplifying molecular interpretations of data obtained from genetically modified animal models of human diseases.
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Montgomery J, Richardson WJ, Marsh S, Rhett JM, Bustos F, Degen K, Ghatnekar GS, Grek CL, Jourdan LJ, Holmes JW, Gourdie RG. The connexin 43 carboxyl terminal mimetic peptide αCT1 prompts differentiation of a collagen scar matrix in humans resembling unwounded skin. FASEB J 2021; 35:e21762. [PMID: 34246197 DOI: 10.1096/fj.202001881r] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 06/02/2021] [Accepted: 06/14/2021] [Indexed: 12/12/2022]
Abstract
Phase II clinical trials have reported that acute treatment of surgical skin wounds with the therapeutic peptide alpha Connexin Carboxy-Terminus 1 (αCT1) improves cutaneous scar appearance by 47% 9-month postsurgery. While Cx43 and ZO-1 have been identified as molecular targets of αCT1, the mode-of-action of the peptide in scar mitigation at cellular and tissue levels remains to be further characterized. Scar histoarchitecture in αCT1 and vehicle-control treated skin wounds within the same patient were compared using biopsies from a Phase I clinical trial at 29-day postwounding. The sole effect on scar structure of a range of epidermal and dermal variables examined was that αCT1-treated scars had less alignment of collagen fibers relative to control wounds-a characteristic that resembles unwounded skin. The with-in subject effect of αCT1 on scar collagen order observed in Phase I testing in humans was recapitulated in Sprague-Dawley rats and the IAF hairless guinea pig. Transient increase in histologic collagen density in response to αCT1 was also observed in both animal models. Mouse NIH 3T3 fibroblasts and primary human dermal fibroblasts treated with αCT1 in vitro showed more rapid closure in scratch wound assays, with individual cells showing decreased directionality in movement. An agent-based computational model parameterized with fibroblast motility data predicted collagen alignments in simulated scars consistent with that observed experimentally in human and the animal models. In conclusion, αCT1 prompts decreased directionality of fibroblast movement and the generation of a 3D collagen matrix postwounding that is similar to unwounded skin-changes that correlate with long-term improvement in scar appearance.
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Affiliation(s)
- Jade Montgomery
- Fralin Biomedical Research Institute, Center for Vascular and Heart Research, Virginia Tech Carilion, Roanoke, VA, USA.,Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA
| | | | - Spencer Marsh
- Fralin Biomedical Research Institute, Center for Vascular and Heart Research, Virginia Tech Carilion, Roanoke, VA, USA
| | - J Matthew Rhett
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA
| | - Francis Bustos
- Fralin Biomedical Research Institute, Center for Vascular and Heart Research, Virginia Tech Carilion, Roanoke, VA, USA.,Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
| | - Katherine Degen
- Fralin Biomedical Research Institute, Center for Vascular and Heart Research, Virginia Tech Carilion, Roanoke, VA, USA.,Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA
| | | | | | - L Jane Jourdan
- Fralin Biomedical Research Institute, Center for Vascular and Heart Research, Virginia Tech Carilion, Roanoke, VA, USA
| | - Jeffrey W Holmes
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Robert G Gourdie
- Fralin Biomedical Research Institute, Center for Vascular and Heart Research, Virginia Tech Carilion, Roanoke, VA, USA.,Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA.,Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
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6
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Yang Y, Liu W, Wei J, Cui Y, Zhang D, Xie J. Transforming growth factor-β1-induced N-cadherin drives cell-cell communication through connexin43 in osteoblast lineage. Int J Oral Sci 2021; 13:15. [PMID: 33850101 PMCID: PMC8044142 DOI: 10.1038/s41368-021-00119-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/29/2020] [Accepted: 02/01/2021] [Indexed: 02/05/2023] Open
Abstract
Gap junction (GJ) has been indicated to have an intimate correlation with adhesion junction. However, the direct interaction between them partially remains elusive. In the current study, we aimed to elucidate the role of N-cadherin, one of the core components in adhesion junction, in mediating connexin 43, one of the functional constituents in gap junction, via transforming growth factor-β1(TGF-β1) induction in osteoblasts. We first elucidated the expressions of N-cadherin induced by TGF-β1 and also confirmed the upregulation of Cx43, and the enhancement of functional gap junctional intercellular communication (GJIC) triggered by TGF-β1 in both primary osteoblasts and MC3T3 cell line. Colocalization analysis and Co-IP experimentation showed that N-cadherin interacts with Cx43 at the site of cell-cell contact. Knockdown of N-cadherin by siRNA interference decreased the Cx43 expression and abolished the promoting effect of TGF-β1 on Cx43. Functional GJICs in living primary osteoblasts and MC3T3 cell line were also reduced. TGF-β1-induced increase in N-cadherin and Cx43 was via Smad3 activation, whereas knockdown of Smad3 signaling by using siRNA decreased the expressions of both N-cadherin and Cx43. Overall, these data indicate the direct interactions between N-cadherin and Cx43, and reveal the intervention of adhesion junction in functional gap junction in living osteoblasts.
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Affiliation(s)
- Yueyi Yang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Wenjing Liu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - JieYa Wei
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yujia Cui
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Demao Zhang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management & West China Hospital of Stomatology, Sichuan University, Chengdu, China.
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7
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Cano‐Ballesteros S, Palmquist‐Gomes P, Marín‐Sedeño E, Guadix JA, Pérez‐Pomares JM. Fsp1 cardiac embryonic expression delineates atrioventricular endocardial cushion, coronary venous and lymphatic valve development. J Anat 2021; 238:508-514. [PMID: 32920869 PMCID: PMC7812130 DOI: 10.1111/joa.13306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 08/07/2020] [Accepted: 08/10/2020] [Indexed: 02/03/2023] Open
Abstract
Fsp1 (a.k.a S100A4 or Metastatin) is an intracellular and secreted protein widely regarded as a fibroblast marker. Recent studies have nonetheless shown that Fsp1 is also expressed by other cell types, including small subsets of endothelial cells. Since no detailed and systematic description of Fsp1 spatio-temporal expression pattern in cardiac vascular cells is available in the literature, we have used a transgenic murine line (Fsp1-GFP) to study Fsp1 expression in the developing and postnatal cardiac vasculature and endocardium. Our work shows that Fsp1 is expressed in the endocardium and mesenchyme of atrioventricular valve primordia, as well as in some coronary venous and lymphatic endothelial cells. Fsp1 expression in cardiac venous and lymphatic endothelium is progressively restricted to the leaflets of cardiac venous and lymphatic valves. Our results suggest that Fsp1 could play a role in the development of atrioventricular valves and participate in the patterning and morphogenesis of cardiac venous and lymphatic vessel valves.
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Affiliation(s)
- Sara Cano‐Ballesteros
- Department of Animal Biology, Faculty of SciencesInstituto Malagueño de Biomedicina (IBIMA), University of MálagaMálagaSpain,BIONAND, Centro Andaluz de Nanomedicina y BiotecnologíaJunta de AndalucíaUniversidad de MálagaMálagaSpain
| | - Paul Palmquist‐Gomes
- Department of Animal Biology, Faculty of SciencesInstituto Malagueño de Biomedicina (IBIMA), University of MálagaMálagaSpain,BIONAND, Centro Andaluz de Nanomedicina y BiotecnologíaJunta de AndalucíaUniversidad de MálagaMálagaSpain
| | - Ernesto Marín‐Sedeño
- Department of Animal Biology, Faculty of SciencesInstituto Malagueño de Biomedicina (IBIMA), University of MálagaMálagaSpain,BIONAND, Centro Andaluz de Nanomedicina y BiotecnologíaJunta de AndalucíaUniversidad de MálagaMálagaSpain
| | - Juan Antonio Guadix
- Department of Animal Biology, Faculty of SciencesInstituto Malagueño de Biomedicina (IBIMA), University of MálagaMálagaSpain,BIONAND, Centro Andaluz de Nanomedicina y BiotecnologíaJunta de AndalucíaUniversidad de MálagaMálagaSpain
| | - José María Pérez‐Pomares
- Department of Animal Biology, Faculty of SciencesInstituto Malagueño de Biomedicina (IBIMA), University of MálagaMálagaSpain,BIONAND, Centro Andaluz de Nanomedicina y BiotecnologíaJunta de AndalucíaUniversidad de MálagaMálagaSpain
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8
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Solan JL, Lampe PD. Src Regulation of Cx43 Phosphorylation and Gap Junction Turnover. Biomolecules 2020; 10:biom10121596. [PMID: 33255329 PMCID: PMC7759836 DOI: 10.3390/biom10121596] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/19/2020] [Accepted: 11/22/2020] [Indexed: 12/18/2022] Open
Abstract
The gap junction protein Connexin43 (Cx43) is highly regulated by phosphorylation at over a dozen sites by probably at least as many kinases. This Cx43 “kinome” plays an important role in gap junction assembly and turnover. We sought to gain a better understanding of the interrelationship of these phosphorylation events particularly related to src activation and Cx43 turnover. Using state-of-the-art live imaging methods, specific inhibitors and many phosphorylation-status specific antibodies, we found phospho-specific domains in gap junction plaques and show evidence that multiple pathways of disassembly exist and can be regulated at the cellular and subcellular level. We found Src activation promotes formation of connexisomes (internalized gap junctions) in a process involving ERK-mediated phosphorylation of S279/282. Proteasome inhibition dramatically and rapidly restored gap junctions in the presence of Src and led to dramatic changes in the Cx43 phospho-profile including to increased Y247, Y265, S279/282, S365, and S373 phosphorylation. Lysosomal inhibition, on the other hand, nearly eliminated phosphorylation on Y247 and Y265 and reduced S368 and S373 while increasing S279/282 phosphorylation levels. We present a model of gap junction disassembly where multiple modes of disassembly are regulated by phosphorylation and can have differential effects on cellular signaling.
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Affiliation(s)
- Joell L. Solan
- Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA;
| | - Paul D. Lampe
- Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA;
- Department of Global Health, Pathobiology Program, University of Washington, Seattle, WA 98109, USA
- Correspondence:
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9
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Da Z, Gao L, Su G, Yao J, Fu W, Zhang J, Zhang X, Pei Z, Yue P, Bai B, Lin Y, Meng W, Li X. Bioinformatics combined with quantitative proteomics analyses and identification of potential biomarkers in cholangiocarcinoma. Cancer Cell Int 2020; 20:130. [PMID: 32336950 PMCID: PMC7178764 DOI: 10.1186/s12935-020-01212-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/15/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Cholangiocarcinoma (CCA) is an invasive malignancy arising from biliary epithelial cells; it is the most common primary tumour of the bile tract and has a poor prognosis. The aim of this study was to screen prognostic biomarkers for CCA by integrated multiomics analysis. METHODS The GSE32225 dataset was derived from the Gene Expression Omnibus (GEO) database and comprehensively analysed by using R software and The Cancer Genome Atlas (TCGA) database to obtain the differentially expressed RNAs (DERNAs) associated with CCA prognosis. Quantitative isobaric tags for relative and absolute quantification (iTRAQ) proteomics was used to screen differentially expressed proteins (DEPs) between CCA and nontumour tissues. Through integrated analysis of DERNA and DEP data, we obtained candidate proteins APOF, ITGAV and CASK, and immunohistochemistry was used to detect the expression of these proteins in CCA. The relationship between CASK expression and CCA prognosis was further analysed. RESULTS Through bioinformatics analysis, 875 DERNAs were identified, of which 10 were associated with the prognosis of the CCA patients. A total of 487 DEPs were obtained by using the iTRAQ technique. Comprehensive analysis of multiomics data showed that CASK, ITGAV and APOF expression at both the mRNA and protein levels were different in CCA compared with nontumour tissues. CASK was found to be expressed in the cytoplasm and nucleus of CCA cells in 38 (45%) of 84 patients with CCA. Our results suggested that patients with positive CASK expression had significantly better overall survival (OS) and recurrence-free survival (RFS) than those with negative CASK expression. Univariate and multivariate analyses demonstrated that negative expression of CASK was a significantly independent risk factor for OS and RFS in CCA patients. CONCLUSIONS CASK may be a tumour suppressor; its low expression is an independent risk factor for a poor prognosis in CCA patients, and so it could be used as a clinically valuable prognostic marker.
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Affiliation(s)
- Zijian Da
- The First Clinical Medical College, Lanzhou University, Lanzhou, 730000 China
| | - Long Gao
- The First Clinical Medical College, Lanzhou University, Lanzhou, 730000 China
| | - Gang Su
- Institute of Genetics, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000 China
| | - Jia Yao
- The First Clinical Medical College, Lanzhou University, Lanzhou, 730000 China
- Division of Scientific Research and Development Planning, The First Hospital of Lanzhou University, Lanzhou, 730000 China
| | - Wenkang Fu
- The First Clinical Medical College, Lanzhou University, Lanzhou, 730000 China
| | - Jinduo Zhang
- Department of Special Minimally Invasive Surgery, The First Hospital of Lanzhou University, Lanzhou, 730000 China
- Gansu Province Institute of Hepatopancreatobiliary, Lanzhou, 730000 China
- Gansu Province Key Laboratory Biotherapy and Regenerative Medicine, Lanzhou, 730000 China
| | - Xu Zhang
- The First Clinical Medical College, Lanzhou University, Lanzhou, 730000 China
| | - Zhaoji Pei
- The First Clinical Medical College, Lanzhou University, Lanzhou, 730000 China
| | - Ping Yue
- Department of Special Minimally Invasive Surgery, The First Hospital of Lanzhou University, Lanzhou, 730000 China
- Gansu Province Institute of Hepatopancreatobiliary, Lanzhou, 730000 China
- Gansu Province Key Laboratory Biotherapy and Regenerative Medicine, Lanzhou, 730000 China
| | - Bing Bai
- Department of Special Minimally Invasive Surgery, The First Hospital of Lanzhou University, Lanzhou, 730000 China
- Gansu Province Institute of Hepatopancreatobiliary, Lanzhou, 730000 China
- Gansu Province Key Laboratory Biotherapy and Regenerative Medicine, Lanzhou, 730000 China
| | - Yanyan Lin
- Department of Special Minimally Invasive Surgery, The First Hospital of Lanzhou University, Lanzhou, 730000 China
- Gansu Province Institute of Hepatopancreatobiliary, Lanzhou, 730000 China
- Gansu Province Key Laboratory Biotherapy and Regenerative Medicine, Lanzhou, 730000 China
| | - Wenbo Meng
- The First Clinical Medical College, Lanzhou University, Lanzhou, 730000 China
- Department of Special Minimally Invasive Surgery, The First Hospital of Lanzhou University, Lanzhou, 730000 China
- Division of Scientific Research and Development Planning, The First Hospital of Lanzhou University, Lanzhou, 730000 China
- Institute of Genetics, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000 China
- Gansu Province Institute of Hepatopancreatobiliary, Lanzhou, 730000 China
- Gansu Province Key Laboratory Biotherapy and Regenerative Medicine, Lanzhou, 730000 China
| | - Xun Li
- The First Clinical Medical College, Lanzhou University, Lanzhou, 730000 China
- Gansu Province Institute of Hepatopancreatobiliary, Lanzhou, 730000 China
- Gansu Province Key Laboratory Biotherapy and Regenerative Medicine, Lanzhou, 730000 China
- The Second Department of General Surgery, The First Hospital of Lanzhou University, Lanzhou, 730000 China
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10
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Abstract
The connexin family of channel-forming proteins is present in every tissue type in the human anatomy. Connexins are best known for forming clustered intercellular channels, structurally known as gap junctions, where they serve to exchange members of the metabolome between adjacent cells. In their single-membrane hemichannel form, connexins can act as conduits for the passage of small molecules in autocrine and paracrine signalling. Here, we review the roles of connexins in health and disease, focusing on the potential of connexins as therapeutic targets in acquired and inherited diseases as well as wound repair, while highlighting the associated clinical challenges.
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11
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Montgomery J, Ghatnekar GS, Grek CL, Moyer KE, Gourdie RG. Connexin 43-Based Therapeutics for Dermal Wound Healing. Int J Mol Sci 2018; 19:ijms19061778. [PMID: 29914066 PMCID: PMC6032231 DOI: 10.3390/ijms19061778] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/08/2018] [Accepted: 06/12/2018] [Indexed: 12/22/2022] Open
Abstract
The most ubiquitous gap junction protein within the body, connexin 43 (Cx43), is a target of interest for modulating the dermal wound healing response. Observational studies found associations between Cx43 at the wound edge and poor healing response, and subsequent studies utilizing local knockdown of Cx43 found improvements in wound closure rate and final scar appearance. Further preclinical work conducted using Cx43-based peptide therapeutics, including alpha connexin carboxyl terminus 1 (αCT1), a peptide mimetic of the Cx43 carboxyl terminus, reported similar improvements in wound healing and scar formation. Clinical trials and further study into the mode of action have since been conducted on αCT1, and Phase III testing for treatment of diabetic foot ulcers is currently underway. Therapeutics targeting connexin activity show promise in beneficially modulating the human body’s natural healing response for improved patient outcomes across a variety of injuries.
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Affiliation(s)
- Jade Montgomery
- Virginia Tech Carilion Research Institute, Roanoke, VA 24016, USA.
- School of Biomedical Engineering and Sciences, Virginia Tech-Wake Forest University, Blacksburg, VA 24061, USA.
| | | | | | - Kurtis E Moyer
- Department of Surgery, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA.
- Department of Surgery, Carilion Clinic, Roanoke, VA 24016, USA.
| | - Robert G Gourdie
- Virginia Tech Carilion Research Institute, Roanoke, VA 24016, USA.
- School of Biomedical Engineering and Sciences, Virginia Tech-Wake Forest University, Blacksburg, VA 24061, USA.
- Department of Emergency Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA.
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12
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Sorgen PL, Trease AJ, Spagnol G, Delmar M, Nielsen MS. Protein⁻Protein Interactions with Connexin 43: Regulation and Function. Int J Mol Sci 2018; 19:E1428. [PMID: 29748463 PMCID: PMC5983787 DOI: 10.3390/ijms19051428] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 12/11/2022] Open
Abstract
Connexins are integral membrane building blocks that form gap junctions, enabling direct cytoplasmic exchange of ions and low-molecular-mass metabolites between adjacent cells. In the heart, gap junctions mediate the propagation of cardiac action potentials and the maintenance of a regular beating rhythm. A number of connexin interacting proteins have been described and are known gap junction regulators either through direct effects (e.g., kinases) or the formation of larger multifunctional complexes (e.g., cytoskeleton scaffold proteins). Most connexin partners can be categorized as either proteins promoting coupling by stimulating forward trafficking and channel opening or inhibiting coupling by inducing channel closure, internalization, and degradation. While some interactions have only been implied through co-localization using immunohistochemistry, others have been confirmed by biophysical methods that allow detection of a direct interaction. Our understanding of these interactions is, by far, most well developed for connexin 43 (Cx43) and the scope of this review is to summarize our current knowledge of their functional and regulatory roles. The significance of these interactions is further exemplified by demonstrating their importance at the intercalated disc, a major hub for Cx43 regulation and Cx43 mediated effects.
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Affiliation(s)
- Paul L Sorgen
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Andrew J Trease
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Gaelle Spagnol
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Mario Delmar
- Leon H Charney Division of Cardiology, NYU School of Medicine, New York, NY 10016, USA.
| | - Morten S Nielsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark.
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13
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Chanson M, Watanabe M, O'Shaughnessy EM, Zoso A, Martin PE. Connexin Communication Compartments and Wound Repair in Epithelial Tissue. Int J Mol Sci 2018; 19:ijms19051354. [PMID: 29751558 PMCID: PMC5983803 DOI: 10.3390/ijms19051354] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 12/20/2022] Open
Abstract
Epithelial tissues line the lumen of tracts and ducts connecting to the external environment. They are critical in forming an interface between the internal and external environment and, following assault from environmental factors and pathogens, they must rapidly repair to maintain cellular homeostasis. These tissue networks, that range from a single cell layer, such as in airway epithelium, to highly stratified and differentiated epithelial surfaces, such as the epidermis, are held together by a junctional nexus of proteins including adherens, tight and gap junctions, often forming unique and localised communication compartments activated for localised tissue repair. This review focuses on the dynamic changes that occur in connexins, the constituent proteins of the intercellular gap junction channel, during wound-healing processes and in localised inflammation, with an emphasis on the lung and skin. Current developments in targeting connexins as corrective therapies to improve wound closure and resolve localised inflammation are also discussed. Finally, we consider the emergence of the zebrafish as a concerted whole-animal model to study, visualise and track the events of wound repair and regeneration in real-time living model systems.
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Affiliation(s)
- Marc Chanson
- Department of Pediatrics and Cell Physiology & Metabolism, Geneva University Hospitals and University of Geneva, 1211 Geneva, Switzerland.
| | - Masakatsu Watanabe
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan.
| | - Erin M O'Shaughnessy
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Alice Zoso
- Department of Pediatrics and Cell Physiology & Metabolism, Geneva University Hospitals and University of Geneva, 1211 Geneva, Switzerland.
| | - Patricia E Martin
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
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14
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Abstract
Fifty years ago, tumour cells were found to lack electrical coupling, leading to the hypothesis that loss of direct intercellular communication is commonly associated with cancer onset and progression. Subsequent studies linked this phenomenon to gap junctions composed of connexin proteins. Although many studies support the notion that connexins are tumour suppressors, recent evidence suggests that, in some tumour types, they may facilitate specific stages of tumour progression through both junctional and non-junctional signalling pathways. This Timeline article highlights the milestones connecting gap junctions to cancer, and underscores important unanswered questions, controversies and therapeutic opportunities in the field.
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Affiliation(s)
- Trond Aasen
- (Co-corresponding authors) Correspondence to
T.A. () and D.W.L.
()
| | - Marc Mesnil
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences
Fondamentales et Appliquées, Université de Poitiers, Poitiers,
France
| | - Christian C. Naus
- Department of Cellular and Physiological Sciences, The Life
Sciences Institute, University of British Columbia, Vancouver, British
Columbia, Canada
| | - Paul D. Lampe
- Translational Research Program, Fred Hutchinson Cancer Research
Center, Seattle, United States
| | - Dale W. Laird
- (Co-corresponding authors) Correspondence to
T.A. () and D.W.L.
()
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15
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Grek CL, Montgomery J, Sharma M, Ravi A, Rajkumar JS, Moyer KE, Gourdie RG, Ghatnekar GS. A Multicenter Randomized Controlled Trial Evaluating a Cx43-Mimetic Peptide in Cutaneous Scarring. J Invest Dermatol 2016; 137:620-630. [PMID: 27856288 DOI: 10.1016/j.jid.2016.11.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 10/24/2016] [Accepted: 11/03/2016] [Indexed: 01/06/2023]
Abstract
The transmembrane protein Cx43 has key roles in fibrogenic processes including inflammatory signaling and extracellular matrix composition. aCT1 is a Cx43 mimetic peptide that in preclinical studies accelerated wound closure, decreased inflammation and granulation tissue area, and normalized mechanical properties after cutaneous injury. We evaluated the efficacy and safety of aCT1 in the reduction of scar formation in human incisional wounds. In a prospective, multicenter, within-participant controlled trial, patients with bilateral incisional wounds (≥10 mm) after laparoscopic surgery were randomized to receive acute treatment (immediately after wounding and 24 hours later) with an aCT1 gel formulation plus conventional standard of care protocols, involving moisture-retentive occlusive dressing, or standard of care alone. The primary efficacy endpoint was average scarring score using visual analog scales evaluating incision appearance and healing progress over 9 months. There was no significant difference in scar appearance between aCT1- or control-treated incisions after 1 month. At month 9, aCT1-treated incisions showed a 47% improvement in scar scores over controls (Vancouver Scar Scale; P = 0.0045), a significantly higher Global Assessment Scale score (P = 0.0009), and improvements in scar pigmentation, thickness, surface roughness, and mechanical suppleness. Adverse events were similar in both groups. aCT1 has potential to improve scarring outcome after surgery.
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Affiliation(s)
| | - Jade Montgomery
- Virginia Tech Carilion Research Institute, Center for Heart and Regenerative Medicine Research, Roanoke, Virginia, USA; Virginia Tech School of Biomedical Engineering and Sciences, Blacksburg, Virginia, USA
| | | | - A Ravi
- Sri Ramachandra Medical Centre, Sri Ramachandra University, Porur Chennai, Tamil Nadu, India
| | - J S Rajkumar
- Life Line Multispecialty Hospital, Chennai, Tamil Nadu, India
| | - Kurtis E Moyer
- Virginia Tech Carilion Research Institute, Center for Heart and Regenerative Medicine Research, Roanoke, Virginia, USA; Virginia Tech School of Biomedical Engineering and Sciences, Blacksburg, Virginia, USA; Department of Emergency Medicine, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Department of Surgery, Division of Plastic Surgery, Carilion Clinic, Roanoke, Virginia, USA
| | - Robert G Gourdie
- Virginia Tech Carilion Research Institute, Center for Heart and Regenerative Medicine Research, Roanoke, Virginia, USA; Virginia Tech School of Biomedical Engineering and Sciences, Blacksburg, Virginia, USA; Department of Emergency Medicine, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
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16
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LaConte LEW, Chavan V, Liang C, Willis J, Schönhense EM, Schoch S, Mukherjee K. CASK stabilizes neurexin and links it to liprin-α in a neuronal activity-dependent manner. Cell Mol Life Sci 2016; 73:3599-621. [PMID: 27015872 PMCID: PMC4982824 DOI: 10.1007/s00018-016-2183-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 02/23/2016] [Accepted: 03/14/2016] [Indexed: 11/28/2022]
Abstract
CASK, a MAGUK family protein, is an essential protein present in the presynaptic compartment. CASK's cellular role is unknown, but it interacts with multiple proteins important for synapse formation and function, including neurexin, liprin-α, and Mint1. CASK phosphorylates neurexin in a divalent ion-sensitive manner, although the functional relevance of this activity is unclear. Here we find that liprin-α and Mint1 compete for direct binding to CASK, but neurexin1β eliminates this competition, and all four proteins form a complex. We describe a novel mode of interaction between liprin-α and CASK when CASK is bound to neurexin1β. We show that CASK phosphorylates neurexin, modulating the interaction of liprin-α with the CASK-neurexin1β-Mint1 complex. Thus, CASK creates a regulatory and structural link between the presynaptic adhesion molecule neurexin and active zone organizer, liprin-α. In neuronal culture, CASK appears to regulate the stability of neurexin by linking it with this multi-protein presynaptic active zone complex.
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Affiliation(s)
- Leslie E W LaConte
- Virginia Tech Carilion Research Institute, 2 Riverside Cir., Roanoke, VA, 24016, USA
| | - Vrushali Chavan
- Virginia Tech Carilion Research Institute, 2 Riverside Cir., Roanoke, VA, 24016, USA
| | - Chen Liang
- Virginia Tech Carilion Research Institute, 2 Riverside Cir., Roanoke, VA, 24016, USA
| | - Jeffery Willis
- Virginia Tech Carilion Research Institute, 2 Riverside Cir., Roanoke, VA, 24016, USA
| | | | - Susanne Schoch
- Institute of Neuropathology, Sigmund Freud Strasse 25, 53105, Bonn, Germany
| | - Konark Mukherjee
- Virginia Tech Carilion Research Institute, 2 Riverside Cir., Roanoke, VA, 24016, USA.
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24060, USA.
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17
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X-linked intellectual disability gene CASK regulates postnatal brain growth in a non-cell autonomous manner. Acta Neuropathol Commun 2016; 4:30. [PMID: 27036546 PMCID: PMC4818453 DOI: 10.1186/s40478-016-0295-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 03/07/2016] [Indexed: 01/07/2023] Open
Abstract
The phenotypic spectrum among girls with heterozygous mutations in the X-linked intellectual disability (XLID) gene CASK (calcium/calmodulin-dependent serine protein kinase) includes postnatal microcephaly, ponto-cerebellar hypoplasia, seizures, optic nerve hypoplasia, growth retardation and hypotonia. Although CASK knockout mice were previously reported to exhibit perinatal lethality and a 3-fold increased apoptotic rate in the brain, CASK deletion was not found to affect neuronal physiology and their electrical properties. The pathogenesis of CASK associated disorders and the potential function of CASK therefore remains unknown. Here, using Cre-LoxP mediated gene excision experiments; we demonstrate that deleting CASK specifically from mouse cerebellar neurons does not alter the cerebellar architecture or function. We demonstrate that the neuron-specific deletion of CASK in mice does not cause perinatal lethality but induces severe recurrent epileptic seizures and growth retardation before the onset of adulthood. Furthermore, we demonstrate that although neuron-specific haploinsufficiency of CASK is inconsequential, the CASK mutation associated human phenotypes are replicated with high fidelity in CASK heterozygous knockout female mice (CASK(+/-)). These data suggest that CASK-related phenotypes are not purely neuronal in origin. Surprisingly, the observed microcephaly in CASK(+/-) animals is not associated with a specific loss of CASK null brain cells indicating that CASK regulates postnatal brain growth in a non-cell autonomous manner. Using biochemical assay, we also demonstrate that CASK can interact with metabolic proteins. CASK knockdown in human cell lines cause reduced cellular respiration and CASK(+/-) mice display abnormalities in muscle and brain oxidative metabolism, suggesting a novel function of CASK in metabolism. Our data implies that some phenotypic components of CASK heterozygous deletion mutation associated disorders represent systemic manifestation of metabolic stress and therefore amenable to therapeutic intervention.
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18
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Kinase programs spatiotemporally regulate gap junction assembly and disassembly: Effects on wound repair. Semin Cell Dev Biol 2015; 50:40-8. [PMID: 26706150 DOI: 10.1016/j.semcdb.2015.12.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 12/08/2015] [Indexed: 01/05/2023]
Abstract
Gap junctions are highly ordered plasma membrane domains that are constantly assembled, remodeled and turned over due to the short half-life of connexins, the integral membrane proteins that form gap junctions. Connexin 43 (Cx43), by far the most widely expressed connexin, is phosphorylated at multiple serine residues in the cytoplasmic, C-terminal region allowing for exquisite cellular control over gap junctional communication. This is evident during epidermal wounding where spatiotemporal changes in connexin expression occur as cells are instructed whether to die, proliferate or migrate to promote repair. Early gap junctional communication is required for initiation of keratinocyte migration, but accelerated Cx43 turnover is also critical for proper wound healing at later stages. These events are controlled via a "kinase program" where sequential phosphorylation of Cx43 leads to reductions in Cx43's half-life and significant depletion of gap junctions from the plasma membrane within several hours. The complex regulation of gap junction assembly and turnover affords several steps where intervention might speed wound healing.
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19
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Zhou X, Xu G, Yin C, Jin W, Zhang G. Down-regulation of miR-203 induced by Helicobacter pylori infection promotes the proliferation and invasion of gastric cancer by targeting CASK. Oncotarget 2015; 5:11631-40. [PMID: 25373785 PMCID: PMC4294334 DOI: 10.18632/oncotarget.2600] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Accepted: 10/18/2014] [Indexed: 01/01/2023] Open
Abstract
Several microRNAs (miRNA) have been implicated in H. pylori related gastric cancer (GC). However, the molecular mechanism of miRNAs in GC has not been fully understood. In this study, we reported that miR-203 is significantly down-regulated in H. pylori positive tissues and cells and in tumor tissues with important functional consequences. Ectopic expression of miR-203 dramatically suppressed cell proliferation and invasion. We found that miR-203 strongly reduced the expression of CASK oncogene in GC cells. Similar to the restoring miR-203 expression, CASK down-regulation inhibited cell growth and invasion, whereas CASK over-expression rescued the suppressive effect of miR-203. These results can also be found in nude mice. In clinical specimens, CASK was over-expressed in tumors and H. pylori positive tissues and its mRNA levels were inversely correlated with miR-203 expression. Taken together, our results indicated that miR-203 functions as a growth-suppressive miRNA in H. pylori related GC, and that its suppressive effects are mediated mainly by repressing CASK expression.
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Affiliation(s)
- Xiaoying Zhou
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China. First Clinical Medical College of Nanjing Medical University, Nanjing, China
| | - Guifang Xu
- Department of Gastroenterology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Chengqiang Yin
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China. First Clinical Medical College of Nanjing Medical University, Nanjing, China
| | - Wujuan Jin
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China. First Clinical Medical College of Nanjing Medical University, Nanjing, China
| | - Guoxin Zhang
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China. First Clinical Medical College of Nanjing Medical University, Nanjing, China
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20
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Abstract
Connexin mutations underlie numerous human genetic diseases. Several connexin genes have been linked to skin diseases, and mechanistic studies have indicated that a gain of abnormal channel function may be responsible for pathology. The topical accessibility of the epidermal connexins, the existence of several mouse models of human skin disease, and the ongoing identification of pharmacological inhibitors targeting connexins provide an opportunity to test new therapeutic approaches.
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Affiliation(s)
- Noah A Levit
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, United States
| | - Thomas W White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, United States.
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21
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Elbadawy HM, Salvalaio G, Parekh M, Ruzza A, Baruzzo M, Cagini C, Ponzin D, Ferrari S. A superfusion apparatus for ex vivo human eye irritation investigations. Toxicol In Vitro 2015; 29:1619-27. [PMID: 26100225 DOI: 10.1016/j.tiv.2015.06.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 05/26/2015] [Accepted: 06/19/2015] [Indexed: 11/18/2022]
Abstract
A superfusion apparatus (SA) was developed to maintain isolated human corneas ex vivo under conditions which mimic the natural eye environment in vivo, including controlled temperature, tear flow and intraocular pressure. The SA was designed, developed and tested for use in ophthalmic pre-clinical research and to test new pharmaceutical formulations. Corneas undergo an equilibration process in the new physiological environment for one day. The test was then initiated by the application of the test substance, incubation, and temporal assessment of corneal damage using various parameters. The effects of mild and severe irritant concentrations of NaOH (2% and 8%, respectively) on corneal opacity, swelling and epithelial integrity were studied, and the inflammatory status assessed using F4/80 and MPO as macrophages and neutrophils markers, respectively. The SA was then used to test new artificial tear formulations supplemented with silver ions as an active constituent, showing different degrees of inflammatory responses as indicated by the migration of MPO and F4/80 positive cells towards the epithelium. The human cornea superfusion apparatus was proposed as a model for acute eye irritation research.
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Affiliation(s)
- Hossein Mostafa Elbadawy
- International Centre for Ocular Physiopathology, The Eye Bank Foundation of Veneto, Via Paccagnella 11, Padiglione Rama, Venice 30174, Italy.
| | - Gianni Salvalaio
- International Centre for Ocular Physiopathology, The Eye Bank Foundation of Veneto, Via Paccagnella 11, Padiglione Rama, Venice 30174, Italy
| | - Mohit Parekh
- International Centre for Ocular Physiopathology, The Eye Bank Foundation of Veneto, Via Paccagnella 11, Padiglione Rama, Venice 30174, Italy
| | - Alessandro Ruzza
- International Centre for Ocular Physiopathology, The Eye Bank Foundation of Veneto, Via Paccagnella 11, Padiglione Rama, Venice 30174, Italy
| | - Mattia Baruzzo
- International Centre for Ocular Physiopathology, The Eye Bank Foundation of Veneto, Via Paccagnella 11, Padiglione Rama, Venice 30174, Italy
| | - Carlo Cagini
- The Department of Ophthalmology, Perugia General Hospital, University of Perugia, Perugia 06123, Italy
| | - Diego Ponzin
- International Centre for Ocular Physiopathology, The Eye Bank Foundation of Veneto, Via Paccagnella 11, Padiglione Rama, Venice 30174, Italy
| | - Stefano Ferrari
- International Centre for Ocular Physiopathology, The Eye Bank Foundation of Veneto, Via Paccagnella 11, Padiglione Rama, Venice 30174, Italy
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22
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Schulz R, Görge PM, Görbe A, Ferdinandy P, Lampe PD, Leybaert L. Connexin 43 is an emerging therapeutic target in ischemia/reperfusion injury, cardioprotection and neuroprotection. Pharmacol Ther 2015; 153:90-106. [PMID: 26073311 DOI: 10.1016/j.pharmthera.2015.06.005] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 05/29/2015] [Indexed: 12/22/2022]
Abstract
Connexins are widely distributed proteins in the body that are crucially important for heart and brain functions. Six connexin subunits form a connexon or hemichannel in the plasma membrane. Interactions between two hemichannels in a head-to-head arrangement result in the formation of a gap junction channel. Gap junctions are necessary to coordinate cell function by passing electrical current flow between heart and nerve cells or by allowing exchange of chemical signals and energy substrates. Apart from its localization at the sarcolemma of cardiomyocytes and brain cells, connexins are also found in the mitochondria where they are involved in the regulation of mitochondrial matrix ion fluxes and respiration. Connexin expression is affected by age and gender as well as several pathophysiological alterations such as hypertension, hypertrophy, diabetes, hypercholesterolemia, ischemia, post-myocardial infarction remodeling or heart failure, and post-translationally connexins are modified by phosphorylation/de-phosphorylation and nitros(yl)ation which can modulate channel activity. Using knockout/knockin technology as well as pharmacological approaches, one of the connexins, namely connexin 43, has been identified to be important for cardiac and brain ischemia/reperfusion injuries as well as protection from it. Therefore, the current review will focus on the importance of connexin 43 for irreversible injury of heart and brain tissues following ischemia/reperfusion and will highlight the importance of connexin 43 as an emerging therapeutic target in cardio- and neuroprotection.
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Affiliation(s)
- Rainer Schulz
- Institut für Physiologie, JustusLiebig Universität Giessen, Gießen, Germany.
| | | | - Anikó Görbe
- Cardiovascular Research Group, Department of Biochemistry, Faculty of Medicine, University of Szeged, Hungary; Pharmahungary Group, Szeged, Hungary
| | - Péter Ferdinandy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary; Pharmahungary Group, Szeged, Hungary
| | - Paul D Lampe
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Luc Leybaert
- Physiology Group, Department Basic Medical Sciences, Ghent University, Belgium
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23
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The effect of a connexin43-based Peptide on the healing of chronic venous leg ulcers: a multicenter, randomized trial. J Invest Dermatol 2014; 135:289-298. [PMID: 25072595 PMCID: PMC4269806 DOI: 10.1038/jid.2014.318] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/30/2014] [Accepted: 07/14/2014] [Indexed: 12/29/2022]
Abstract
The gap junction protein, connexin43 (Cx43), has critical roles in the inflammatory, edematous, and fibrotic processes following dermal injury and during wound healing, and is abnormally upregulated at the epidermal wound margins of venous leg ulcers (VLUs). Targeting Cx43 with ACT1, a peptide mimetic of the carboxyl-terminus of Cx43, accelerates fibroblast migration and proliferation, and wound reepithelialization. In a prospective, multicenter clinical trial conducted in India, adults with chronic VLUs were randomized to treatment with an ACT1 gel formulation plus conventional standard-of-care (SOC) protocols, involving maintaining wound moisture and four-layer compression bandage therapy, or SOC protocols alone. The primary end point was mean percent ulcer reepithelialization from baseline to 12 weeks. A significantly greater reduction in mean percent ulcer area from baseline to 12 weeks was associated with the incorporation of ACT1 therapy (79% (SD 50.4)) as compared with compression bandage therapy alone (36% (SD 179.8); P=0.02). Evaluation of secondary efficacy end points indicated a reduced median time to 50 and 100% ulcer reepithelialization for ACT1-treated ulcers. Incorporation of ACT1 in SOC protocols may represent a well-tolerated, highly effective therapeutic strategy that expedites chronic venous ulcer healing by treating the underlying ulcer pathophysiology through Cx43-mediated pathways.
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24
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Uzawa K, Kasamatsu A, Shimizu T, Saito Y, Baba T, Sakuma K, Fushimi K, Sakamoto Y, Ogawara K, Shiiba M, Tanzawa H. Suppression of metastasis by mirtazapine via restoration of the Lin-7C/β-catenin pathway in human cancer cells. Sci Rep 2014; 4:5433. [PMID: 24961284 PMCID: PMC4069674 DOI: 10.1038/srep05433] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 06/05/2014] [Indexed: 01/14/2023] Open
Abstract
No definitive therapy exists to treat human metastatic tumors. We reported previously that down-regulation of Lin-7C is essential for metastasis of human squamous cell carcinomas (hSCCs). In this study, we investigated the chemical restoration of Lin-7C expression and demonstrated its effectiveness for suppressing the metastatic potential in human cancer cells. Ingenuity Pathway Analysis (IPA) identified candidate chemical agents, i.e., apomorphine, caffeine, risperidone, quetiapine, and mirtazapine. Among them, mirtazapine, an antagonist of HTR2C, an upstream molecule of Lin-7C, caused substantial up-regulation of the Lin-7C/β-catenin pathway in a metastatic hSCC cell line and human melanoma-derived cell line in vitro, and up-regulation did not contribute to cellular proliferation. Moreover, the antimetastatic effect of mirtazapine in these metastatic cell lines in vivo also was evident in multiple organs of immunodeficient mice with no marked side effects. The current data offer novel information for further study of antimetastatic activity in association with enhanced Lin-7C/β-catenin pathway activation with mirtazapine.
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Affiliation(s)
- Katsuhiro Uzawa
- 1] Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba, Japan [2] Department of Dentistry-Oral and Maxillofacial Surgery, Chiba University Hospital, Chiba, Japan
| | - Atsushi Kasamatsu
- Department of Dentistry-Oral and Maxillofacial Surgery, Chiba University Hospital, Chiba, Japan
| | - Toshihiro Shimizu
- Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yasuhiro Saito
- Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Takao Baba
- Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Kentaro Sakuma
- Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Kazuaki Fushimi
- Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yosuke Sakamoto
- Department of Dentistry-Oral and Maxillofacial Surgery, Chiba University Hospital, Chiba, Japan
| | - Katsunori Ogawara
- Department of Dentistry-Oral and Maxillofacial Surgery, Chiba University Hospital, Chiba, Japan
| | - Masashi Shiiba
- 1] Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba, Japan [2] Department of Medical Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Hideki Tanzawa
- 1] Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba, Japan [2] Department of Dentistry-Oral and Maxillofacial Surgery, Chiba University Hospital, Chiba, Japan
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25
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Martin PE, Easton JA, Hodgins MB, Wright CS. Connexins: sensors of epidermal integrity that are therapeutic targets. FEBS Lett 2014; 588:1304-14. [PMID: 24607543 DOI: 10.1016/j.febslet.2014.02.048] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 02/25/2014] [Accepted: 02/25/2014] [Indexed: 12/25/2022]
Abstract
Gap junction proteins (connexins) are differentially expressed throughout the multiple layers of the epidermis. A variety of skin conditions arise with aberrant connexin expression or function and suggest that maintaining the epidermal gap junction network has many important roles in preserving epidermal integrity and homeostasis. Mutations in a number of connexins lead to epidermal dysplasias giving rise to a range of dermatological disorders of differing severity. 'Gain of function' mutations reveal connexin-mediated roles in calcium signalling within the epidermis. Connexins are involved in epidermal innate immunity, inflammation control and in wound repair. The therapeutic potential of targeting connexins to improve wound healing responses is now clear. This review discusses the role of connexins in epidermal integrity, and examines the emerging evidence that connexins act as epidermal sensors to a variety of mechanical, temperature, pathogen-induced and chemical stimuli. Connexins thus act as an integral component of the skin's protective barrier.
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Affiliation(s)
- Patricia E Martin
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Jennifer A Easton
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow G4 0BA, UK; Department of Dermatology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Malcolm B Hodgins
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow G4 0BA, UK
| | - Catherine S Wright
- Department of Life Sciences and Institute for Applied Health Research, Glasgow Caledonian University, Glasgow G4 0BA, UK
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26
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Kurtenbach S, Kurtenbach S, Zoidl G. Gap junction modulation and its implications for heart function. Front Physiol 2014; 5:82. [PMID: 24578694 PMCID: PMC3936571 DOI: 10.3389/fphys.2014.00082] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/10/2014] [Indexed: 01/04/2023] Open
Abstract
Gap junction communication (GJC) mediated by connexins is critical for heart function. To gain insight into the causal relationship of molecular mechanisms of disease pathology, it is important to understand which mechanisms contribute to impairment of gap junctional communication. Here, we present an update on the known modulators of connexins, including various interaction partners, kinases, and signaling cascades. This gap junction network (GJN) can serve as a blueprint for data mining approaches exploring the growing number of publicly available data sets from experimental and clinical studies.
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Affiliation(s)
- Stefan Kurtenbach
- Department of Psychology, Faculty of Health, York University Toronto, ON, Canada
| | - Sarah Kurtenbach
- Department of Psychology, Faculty of Health, York University Toronto, ON, Canada
| | - Georg Zoidl
- Department of Psychology, Faculty of Health, York University Toronto, ON, Canada ; Department of Biology, Faculty of Science, York University Toronto, ON, Canada ; Center for Vision Research, York University Toronto, ON, Canada
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27
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Solan JL, Lampe PD. Specific Cx43 phosphorylation events regulate gap junction turnover in vivo. FEBS Lett 2014; 588:1423-9. [PMID: 24508467 DOI: 10.1016/j.febslet.2014.01.049] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 01/28/2014] [Accepted: 01/28/2014] [Indexed: 10/25/2022]
Abstract
Gap junctions, composed of proteins from the connexin gene family, are highly dynamic structures that are regulated by kinase-mediated signaling pathways and interactions with other proteins. Phosphorylation of Connexin43 (Cx43) at different sites controls gap junction assembly, gap junction size and gap junction turnover. Here we present a model describing how Akt, mitogen activated protein kinase (MAPK) and src kinase coordinate to regulate rapid turnover of gap junctions. Specifically, Akt phosphorylates Cx43 at S373 eliminating interaction with zona occludens-1 (ZO-1) allowing gap junctions to enlarge. Then MAPK and src phosphorylate Cx43 to initiate turnover. We integrate published data with new data to test and refine this model. Finally, we propose that differential coordination of kinase activation and Cx43 phosphorylation controls the specific routes of disassembly, e.g., annular junction formation or gap junctions can potentially "unzip" and be internalized/endocytosed into the cell that produced each connexin.
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Affiliation(s)
- Joell L Solan
- Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, United States
| | - Paul D Lampe
- Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, United States.
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28
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Fabbretti E. ATP P2X3 receptors and neuronal sensitization. Front Cell Neurosci 2013; 7:236. [PMID: 24363643 PMCID: PMC3849726 DOI: 10.3389/fncel.2013.00236] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/08/2013] [Indexed: 12/21/2022] Open
Abstract
Increasing evidence indicates the importance of extracellular adenosine triphosphate (ATP) in the modulation of neuronal function. In particular, fine control of ATP release and the selective and discrete ATP receptor operation are crucial elements of the crosstalk between neuronal and non-neuronal cells in the peripheral and central nervous systems. In peripheral neurons, ATP signaling gives an important contribution to neuronal sensitization, especially that involved in neuropathic pain. Among other subtypes, P2X3 receptors expressed on sensory neurons are sensitive even to nanomolar concentrations of extracellular ATP, and therefore are important transducers of pain stimuli. P2X3 receptor function is highly sensitive to soluble factors like neuropeptides and neurotrophins, and is controlled by transduction mechanisms, protein-protein interactions and discrete membrane compartmentalization. More recent findings have demonstrated that P2X3 receptors interact with the synaptic scaffold protein calcium/calmodulin-dependent serine protein kinase (CASK) in a state dependent fashion, indicating that CASK plays a crucial role in the modulation of P2X3 receptor stability and efficiency. Activation of P2X3 receptors within CASK/P2X3 complex has important consequences for neuronal plasticity and possibly for the release of neuromodulators and neurotransmitters. Better understanding of the interactome machinery of P2X3 receptors and their integration with other receptors and channels on neuronal surface membranes, is proposed to be essential to unveil the process of neuronal sensitization and related, abnormal pain signaling.
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Affiliation(s)
- Elsa Fabbretti
- University of Nova Gorica, Center for Biomedical Sciences and Engineering Nova Gorica, Slovenia
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29
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Churko JM, Laird DW. Gap junction remodeling in skin repair following wounding and disease. Physiology (Bethesda) 2013; 28:190-8. [PMID: 23636264 DOI: 10.1152/physiol.00058.2012] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the present review, we provide an overview of connexin expression during skin development and remodeling in wound healing, and reflect on how loss- or gain-of-function connexin mutations may change cellular phenotypes and lead to diseases of the skin. We also consider the therapeutic value of targeting connexins in wound healing.
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Affiliation(s)
- Jared M Churko
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
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30
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Dunn CA, Lampe PD. Injury-triggered Akt phosphorylation of Cx43: a ZO-1-driven molecular switch that regulates gap junction size. J Cell Sci 2013; 127:455-64. [PMID: 24213533 DOI: 10.1242/jcs.142497] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The proteins that form vertebrate gap junctions, the connexins, are highly regulated and have short (<2 hour) half-lives. Phosphorylation of connexin43 (Cx43) affects gap junction assembly, channel gating and turnover. After finding dramatic effects on gap junctions with Akt inhibitors, we created an antibody specific for Cx43 phosphorylated on S373, a potential Akt substrate. We found S373 phosphorylation in cells and skin or heart almost exclusively in larger gap-junctional structures that increased dramatically after wounding or hypoxia. We were able to mechanistically show that Akt-dependent phosphorylation of S373 increases gap junction size and communication by completely eliminating the interaction between Cx43 and ZO-1. Thus, phosphorylation on S373 acts as a molecular 'switch' to rapidly increase gap-junctional communication, potentially leading to initiation of activation and migration of keratinocytes or ischemic injury response in the skin and the heart, respectively.
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Affiliation(s)
- Clarence A Dunn
- Translational Research Program, Human Biology and Public Health Sciences Divisions, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109, USA
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31
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Munger SJ, Kanady JD, Simon AM. Absence of venous valves in mice lacking Connexin37. Dev Biol 2013; 373:338-48. [PMID: 23142761 PMCID: PMC3533519 DOI: 10.1016/j.ydbio.2012.10.032] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 10/30/2012] [Accepted: 10/31/2012] [Indexed: 12/31/2022]
Abstract
Venous valves play a crucial role in blood circulation, promoting the one-way movement of blood from superficial and deep veins towards the heart. By preventing retrograde flow, venous valves spare capillaries and venules from being subjected to damaging elevations in pressure, especially during skeletal muscle contraction. Pathologically, valvular incompetence or absence of valves are common features of venous disorders such as chronic venous insufficiency and varicose veins. The underlying causes of these conditions are not well understood, but congenital venous valve aplasia or agenesis may play a role in some cases. Despite progress in the study of cardiac and lymphatic valve morphogenesis, the molecular mechanisms controlling the development and maintenance of venous valves remain poorly understood. Here, we show that in valved veins of the mouse, three gap junction proteins (Connexins, Cxs), Cx37, Cx43, and Cx47, are expressed exclusively in the valves in a highly polarized fashion, with Cx43 on the upstream side of the valve leaflet and Cx37 on the downstream side. Surprisingly, Cx43 expression is strongly induced in the non-valve venous endothelium in superficial veins following wounding of the overlying skin. Moreover, we show that in Cx37-deficient mice, venous valves are entirely absent. Thus, Cx37, a protein involved in cell-cell communication, is one of only a few proteins identified so far as critical for the development or maintenance of venous valves. Because Cxs are necessary for the development of valves in lymphatic vessels as well, our results support the notion of common molecular pathways controlling valve development in veins and lymphatic vessels.
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Affiliation(s)
| | - John D. Kanady
- Department of Physiology, University of Arizona, Tucson, AZ 85724, USA
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