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Wang Q, Schäfer SC, Haefliger JA, Maillard MP, Alonso F. Dietary Potassium Supplementation Reduces Chronic Kidney Lesions Independent of Blood Pressure in Deoxycorticosterone-Acetate and High Sodium Chloride-Treated Mice. Int J Mol Sci 2023; 24:16858. [PMID: 38069178 PMCID: PMC10705941 DOI: 10.3390/ijms242316858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/12/2023] [Accepted: 10/12/2023] [Indexed: 12/18/2023] Open
Abstract
We have previously shown that an excess of deoxycorticosterone acetate and high sodium chloride intake (DOCA/salt) in one-renin gene mice induces a high urinary Na/K ratio, hypokalemia, and cardiac and renal hypertrophy in the absence of hypertension. Dietary potassium supplementation prevents DOCA/salt-induced pathological processes. In the present study, we further study whether DOCA/salt-treated mice progressively develop chronic inflammation and fibrosis in the kidney and whether dietary potassium supplementation can reduce the DOCA/salt-induced renal pathological process. Results showed that (1) long-term DOCA/salt-treated one-renin gene mice developed severe kidney injuries including tubular/vascular hypertrophy, mesangial/interstitial/perivascular fibrosis, inflammation (lymphocyte's immigration), proteinuria, and high serum creatinine in the absence of hypertension; (2) there were over-expressed mRNAs of plasminogen activator inhibitor-1 (PAI-1), fibronectin, collagen type I and III, interferon-inducible protein-10 (IP-10), monocyte chemotactic protein-1 (MCP1), transforming growth factor-β (TGF-β), tumor necrosis factor-alpha (TNF-α), osteopontin, Nuclear factor kappa B (NF-κB)/P65, and intercellular adhesion molecule (ICAM)-1; and (3) dietary potassium supplementation normalized urinary Na/K ratio, hypokalemia, proteinuria, and serum creatinine, reduced renal hypertrophy, inflammations, and fibrosis, and down-regulated mRNA expression of fibronectin, Col-I and III, TGF-β, TNF-α, osteopontin, and ICAM without changes in the blood pressure. The results provide new evidence that potassium and sodium may modulate proinflammatory and fibrotic genes, leading to chronic renal lesions independent of blood pressure.
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Affiliation(s)
- Qing Wang
- Division of Nephrology and Hypertension, Lausanne University Hospital (CHUV), 1011 Lausanne, Switzerland;
| | - Stephan C. Schäfer
- Institute for Pathology, Uniklink Köln, Kerpener Strasse 62, 50937 Köln, Germany;
| | - Jacques-Antoine Haefliger
- Department of Biomedical Sciences, Faculty of Biology and Medicine, Lausanne University, Bugnon 7a, 1005 Lausanne, Switzerland;
| | - Marc P. Maillard
- Division of Nephrology and Hypertension, Lausanne University Hospital (CHUV), 1011 Lausanne, Switzerland;
| | - Florian Alonso
- BioTis, Université de Bordeaux, INSERM U1026, 146 Rue Léo Saignat, 33076 Bordeaux, Cedex, France;
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2
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Abstract
Connexins (Cxs) constitute a large family of transmembrane proteins that form gap junction channels, which enable the direct transfer of small signaling molecules from cell to cell. In blood vessels, Cx channels allow the endothelial cells (ECs) to respond to external and internal cues as a whole and, thus, contribute to the maintenance of vascular homeostasis. While the role of Cxs has been extensively studied in large arteries, a growing body of evidence suggests that they also play a role in the formation of microvascular networks. Since the formation of new blood vessels requires the coordinated response of ECs to external stimuli, endothelial Cxs may play an important role there. Recent studies in developmental and pathologic models reveal that EC Cxs regulate physiological and pathological angiogenesis through canonical and noncanonical functions, making these proteins potential therapeutic targets for the development of new strategies aimed at a better control of angiogenesis.
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Affiliation(s)
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, University of Geneva, Medical Center, 1211 Geneva, Switzerland
| | - Florian Alonso
- Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, 33076 Bordeaux, France
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Hamard L, Santoro T, Allagnat F, Meda P, Nardelli-Haefliger D, Alonso F, Haefliger JA. Targeting connexin37 alters angiogenesis and arteriovenous differentiation in the developing mouse retina. FASEB J 2020; 34:8234-8249. [PMID: 32323401 DOI: 10.1096/fj.202000257r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/20/2020] [Accepted: 04/06/2020] [Indexed: 11/11/2022]
Abstract
Connexin37 (Cx37) forms intercellular channels between endothelial cells (EC), and contributes to coordinate the motor tone of vessels. We investigated the contribution of this protein during physiological angiogenesis. We show that, compared to WT littermates, mice lacking Cx37 (Cx37-/- ) featured (i) a decreased extension of the superficial vascular plexus during the first 4 days after birth; (ii) an increased vascular density at the angiogenic front at P6, due to an increase in the proliferative rate of EC and in the sprouting of the venous compartment, as well as to a somewhat displaced position of tip cells; (iii) a decreased coverage of newly formed arteries and veins by mural cells; (iv) altered ERK-dependent endothelial cells proliferation through the EphB4 signaling pathway, which is involved in the specification of veins and arteries. In vitro studies documented that, in the absence of Cx37, human venous EC (HUVEC) released less platelet-derived growth factor (PDGF) and more Angiopoietin-2, two molecules involved in the recruitment of mural cells. Treatment of mice with DAPT, an inhibitor of the Notch pathway, decreased the expression of Cx37, and partially mimicked in WT retinas, the alterations observed in Cx37-/- mice. Thus, Cx37 contributes to (i) the early angiogenesis of retina, by interacting with the Notch pathway; (ii) the growth and maturation of neo-vessels, by modulating tip, stalk, and mural cells; (iii) the regulation of arteriovenous specification, thus, representing a novel target for treatments of retina diseases.
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Affiliation(s)
- Lauriane Hamard
- Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | - Tania Santoro
- Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | - Florent Allagnat
- Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, Medical Center, University of Geneva, Geneva, Switzerland
| | | | - Florian Alonso
- Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, Bordeaux, France
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4
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Peacock HM, Tabibian A, Criem N, Caolo V, Hamard L, Deryckere A, Haefliger JA, Kwak BR, Zwijsen A, Jones EAV. Impaired SMAD1/5 Mechanotransduction and Cx37 (Connexin37) Expression Enable Pathological Vessel Enlargement and Shunting. Arterioscler Thromb Vasc Biol 2020; 40:e87-e104. [PMID: 32078368 DOI: 10.1161/atvbaha.119.313122] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Impaired ALK1 (activin receptor-like kinase-1)/Endoglin/BMP9 (bone morphogenetic protein 9) signaling predisposes to arteriovenous malformations (AVMs). Activation of SMAD1/5 signaling can be enhanced by shear stress. In the genetic disease hereditary hemorrhagic telangiectasia, which is characterized by arteriovenous malformations, the affected receptors are those involved in the activation of mechanosensitive SMAD1/5 signaling. To elucidate how genetic and mechanical signals interact in AVM development, we sought to identify targets differentially regulated by BMP9 and shear stress. Approach and Results: We identify Cx37 (Connexin37) as a differentially regulated target of ligand-induced and mechanotransduced SMAD1/5 signaling. We show that stimulation of endothelial cells with BMP9 upregulated Cx37, whereas shear stress inhibited this expression. This signaling was SMAD1/5-dependent, and in the absence of SMAD1/5, there was an inversion of the expression pattern. Ablated SMAD1/5 signaling alone caused AVM-like vascular malformations directly connecting the dorsal aorta to the inlet of the heart. In yolk sacs of mouse embryos with an endothelial-specific compound heterozygosity for SMAD1/5, addition of TNFα (tumor necrosis factor-α), which downregulates Cx37, induced development of these direct connections bypassing the yolk sac capillary bed. In wild-type embryos undergoing vascular remodeling, Cx37 was globally expressed by endothelial cells but was absent in regions of enlarging vessels. TNFα and endothelial-specific compound heterozygosity for SMAD1/5 caused ectopic regions lacking Cx37 expression, which correlated to areas of vascular malformations. Mechanistically, loss of Cx37 impairs correct directional migration under flow conditions. CONCLUSIONS Our data demonstrate that Cx37 expression is differentially regulated by shear stress and SMAD1/5 signaling, and that reduced Cx37 expression is permissive for capillary enlargement into shunts.
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Affiliation(s)
- Hanna M Peacock
- From the Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology (H.M.P., A.T., N.C., A.Z., E.A.V.J.), KU Leuven, Belgium
| | - Ashkan Tabibian
- From the Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology (H.M.P., A.T., N.C., A.Z., E.A.V.J.), KU Leuven, Belgium
| | - Nathan Criem
- From the Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology (H.M.P., A.T., N.C., A.Z., E.A.V.J.), KU Leuven, Belgium
| | - Vincenza Caolo
- Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, United Kingdom (V.C.)
| | - Lauriane Hamard
- Department of Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Switzerland (L.H., J.-A.H.)
| | | | - Jacques-Antoine Haefliger
- Department of Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Switzerland (L.H., J.-A.H.)
| | - Brenda R Kwak
- Department of Pathology and Immunology, University of Geneva, Switzerland (B.R.K.)
| | - An Zwijsen
- From the Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology (H.M.P., A.T., N.C., A.Z., E.A.V.J.), KU Leuven, Belgium
| | - Elizabeth A V Jones
- From the Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology (H.M.P., A.T., N.C., A.Z., E.A.V.J.), KU Leuven, Belgium
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5
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Mylonaki I, Allain E, Strano F, Allémann E, Corpataux JM, Meda P, Jordan O, Delie F, Rougemont AL, Haefliger JA, Saucy F. Evaluating intimal hyperplasia under clinical conditions. Interact Cardiovasc Thorac Surg 2019; 27:427-436. [PMID: 29617792 DOI: 10.1093/icvts/ivy101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/04/2018] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Open arterial revascularization using venous segments is frequently associated with the development of intimal hyperplasia (IH), leading to severe restenosis and graft failure. The lack of treatment to prevent this pathology is a major problem. Therefore, we generated a new porcine model, which closely mimics the clinical development of human IH, to test the therapeutic potential of candidate drugs. METHODS A patch of jugular vein was sutured to the right common carotid artery of pigs, to expose the vein to haemodynamic conditions of the arterial bed. Four weeks after surgery, the operated vessels which received no further treatment (the control group) were compared with (i) contralateral, non-operated vessels (the healthy group); (ii) vessels of pigs that received a perivascular application of a drug-free microparticle gel (the placebo group) and (iii) vessels of pigs that perioperatively received the same gel loaded with 10-mg atorvastatin (the atorvastatin group). RESULTS When compared with non-operated vessels, all operated segments displayed a sizable IH which was thicker in the venous patch than in the host artery. These alterations were associated with a thickening of the intima layer of both vessels in the absence of inflammation. The intima/media ratio has been significantly increased by 2000-fold in the vein patches. Perivascular application of atorvastatin did not prevent IH formation. However, the drug increased the adventitial neovascularization in the operated vessels. CONCLUSIONS The novel porcine model allows for monitoring IH formation under haemodynamic conditions which mimic clinical situations. It should facilitate the screening of innovative treatments to prevent restenosis.
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Affiliation(s)
- Ioanna Mylonaki
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Elisabeth Allain
- Department of Vascular Surgery, Lausanne University Hospital, Lausanne, Switzerland
| | - Francesco Strano
- Department of Vascular Surgery, Lausanne University Hospital, Lausanne, Switzerland
| | - Eric Allémann
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Jean-Marc Corpataux
- Department of Vascular Surgery, Lausanne University Hospital, Lausanne, Switzerland
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, University of Geneva, Medical Center, Geneva, Switzerland
| | - Olivier Jordan
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Florence Delie
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Anne-Laure Rougemont
- Division of Clinical Pathology, Geneva University Hospitals, Geneva, Switzerland
| | | | - François Saucy
- Department of Vascular Surgery, Lausanne University Hospital, Lausanne, Switzerland
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6
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Longchamp A, Mirabella T, Arduini A, MacArthur MR, Das A, Treviño-Villarreal JH, Hine C, Ben-Sahra I, Knudsen NH, Brace LE, Reynolds J, Mejia P, Tao M, Sharma G, Wang R, Corpataux JM, Haefliger JA, Ahn KH, Lee CH, Manning BD, Sinclair DA, Chen CS, Ozaki CK, Mitchell JR. Amino Acid Restriction Triggers Angiogenesis via GCN2/ATF4 Regulation of VEGF and H 2S Production. Cell 2019; 173:117-129.e14. [PMID: 29570992 DOI: 10.1016/j.cell.2018.03.001] [Citation(s) in RCA: 201] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/17/2018] [Accepted: 02/27/2018] [Indexed: 12/15/2022]
Abstract
Angiogenesis, the formation of new blood vessels by endothelial cells (ECs), is an adaptive response to oxygen/nutrient deprivation orchestrated by vascular endothelial growth factor (VEGF) upon ischemia or exercise. Hypoxia is the best-understood trigger of VEGF expression via the transcription factor HIF1α. Nutrient deprivation is inseparable from hypoxia during ischemia, yet its role in angiogenesis is poorly characterized. Here, we identified sulfur amino acid restriction as a proangiogenic trigger, promoting increased VEGF expression, migration and sprouting in ECs in vitro, and increased capillary density in mouse skeletal muscle in vivo via the GCN2/ATF4 amino acid starvation response pathway independent of hypoxia or HIF1α. We also identified a requirement for cystathionine-γ-lyase in VEGF-dependent angiogenesis via increased hydrogen sulfide (H2S) production. H2S mediated its proangiogenic effects in part by inhibiting mitochondrial electron transport and oxidative phosphorylation, resulting in increased glucose uptake and glycolytic ATP production.
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Affiliation(s)
- Alban Longchamp
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Surgery and the Heart and Vascular Center, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Teodelinda Mirabella
- Tissue Microfabrication Lab, Department of Biomedical Engineering, Boston University, Boston, MA, USA; Wyss Institute for Biologically Inspired Engineering, Boston, MA, USA
| | - Alessandro Arduini
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Michael R MacArthur
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Abhirup Das
- Glenn Center for the Biological Mechanisms of Aging, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Laboratory for Ageing Research, Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney NSW 2052, Australia
| | | | - Christopher Hine
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Issam Ben-Sahra
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Nelson H Knudsen
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Lear E Brace
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Justin Reynolds
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Pedro Mejia
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Ming Tao
- Department of Surgery and the Heart and Vascular Center, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Gaurav Sharma
- Department of Surgery and the Heart and Vascular Center, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Rui Wang
- Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, ON, Canada
| | - Jean-Marc Corpataux
- Department of Vascular Surgery, Laboratory of Experimental Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Jacques-Antoine Haefliger
- Department of Vascular Surgery, Laboratory of Experimental Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Kyo Han Ahn
- Department of Chemistry, Postech, 77 Cheongam-Ro, Nam-Gu, Pohang, 37673, Republic of Korea
| | - Chih-Hao Lee
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Brendan D Manning
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - David A Sinclair
- Glenn Center for the Biological Mechanisms of Aging, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Laboratory for Ageing Research, Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney NSW 2052, Australia
| | - Christopher S Chen
- Tissue Microfabrication Lab, Department of Biomedical Engineering, Boston University, Boston, MA, USA; Wyss Institute for Biologically Inspired Engineering, Boston, MA, USA
| | - C Keith Ozaki
- Department of Surgery and the Heart and Vascular Center, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - James R Mitchell
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
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Domingos-Pereira S, Sathiyanadan K, La Rosa S, Polák L, Chevalier MF, Martel P, Hojeij R, Derré L, Haefliger JA, Jichlinski P, Nardelli-Haefliger D. Intravesical Ty21a Vaccine Promotes Dendritic Cells and T Cell-Mediated Tumor Regression in the MB49 Bladder Cancer Model. Cancer Immunol Res 2019; 7:621-629. [PMID: 30696629 DOI: 10.1158/2326-6066.cir-18-0671] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/28/2018] [Accepted: 01/25/2019] [Indexed: 11/16/2022]
Abstract
Preclinical data show that intravesical instillation of Ty21a/Vivotif, a commercial vaccine against typhoid fever, is an effective alternative option to standard Bacillus Calmette-Guérin (BCG) immunotherapy for non-muscle-invasive bladder cancer (NMIBC). Here, we characterized the inflammatory effects of Ty21a on the bladder and investigated the immune mechanisms underlying tumor regression toward the use of this bacterial vaccine in NMIBC patients. MB49 bladder tumor-bearing mice had significantly improved survival after intravesical instillations of Ty21a doses of 106 to 108 colony-forming units. By IHC and morphology, both BCG and Ty21a instillations were associated with bladder inflammation, which was decreased with the use of low, but effective doses of Ty21a. Flow-cytometry analysis showed a significant infiltration of T cells, natural killer (NK) cells, and myeloid cells, compared with controls, after a single dose of Ty21a, whereas this was only observed after multiple doses of BCG. The induced myeloid cells were predominantly neutrophils and Ly6C+CD103+ dendritic cells (DC), the latter being significantly more numerous after instillation of Ty21a than BCG. Ex vivo infection of human leukocytes with Ty21a, but not BCG, similarly significantly increased DC frequency. CD4+ and CD8+ T cells, but not NK cells nor neutrophils, were required for effective bladder tumor regression upon Ty21a treatment. Thus, the generation of antitumor adaptive immunity was identified as a key process underlying Ty21a-mediated treatment efficacy. Altogether, these results demonstrate mechanisms behind intravesical Ty21a therapy and suggest its potential as a safe and effective treatment for NMIBC patients.
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Affiliation(s)
| | - Karthik Sathiyanadan
- Department of Urology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Stefano La Rosa
- Service of Clinical Pathology, Institute of Pathology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Lenka Polák
- Department of Urology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Mathieu F Chevalier
- Department of Urology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Paul Martel
- Department of Urology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Rim Hojeij
- Department of Urology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Laurent Derré
- Department of Urology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | | | - Patrice Jichlinski
- Department of Urology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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8
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Kenagy RD, Kikuchi S, Evanko SP, Ruiter MS, Piola M, Longchamp A, Pesce M, Soncini M, Deglise S, Fiore GB, Haefliger JA, Schmidt TA, Majesky MW, Sobel M, Wight TN. Versican is differentially regulated in the adventitial and medial layers of human vein grafts. PLoS One 2018; 13:e0204045. [PMID: 30265729 PMCID: PMC6161854 DOI: 10.1371/journal.pone.0204045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/31/2018] [Indexed: 12/13/2022] Open
Abstract
Changes in extracellular matrix proteins may contribute significantly to the adaptation of vein grafts to the arterial circulation. We examined the production and distribution of versican and hyaluronan in intact human vein rings cultured ex vivo, veins perfused ex vivo, and cultured venous adventitial and smooth muscle cells. Immunohistochemistry revealed higher levels of versican in the intima/media compared to the adventitia, and no differences in hyaluronan. In the vasa vasorum, versican and hyaluronan associated with CD34+ progenitor cells. Culturing the vein rings for 14 days revealed increased versican immunostaining of 30–40% in all layers, with no changes in hyaluronan. Changes in versican accumulation appear to result from increased synthesis in the intima/media and decreased degradation in the adventitia as versican transcripts were increased in the intima/media, but unchanged in the adventitia, and versikine (the ADAMTS-mediated cleavage product of versican) was increased in the intima/media, but decreased in the adventitia. In perfused human veins, versican was specifically increased in the intima/media in the presence of venous pressure, but not with arterial pressure. Unexpectedly, cultured adventitial cells express and accumulate more versican and hyaluronan than smooth muscle cells. These data demonstrate a differential regulation of versican and hyaluronan in human venous adventitia vs. intima/media and suggest distinct functions for these extracellular matrix macromolecules in these venous wall compartments during the adaptive response of vein grafts to the arterial circulation.
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Affiliation(s)
- Richard D. Kenagy
- Center for Cardiovascular Biology, Institute for Stem Cells and Regenerative Medicine, and Department of Surgery, University of Washington, Seattle, WA, United States of America
- * E-mail:
| | - Shinsuke Kikuchi
- Department of Vascular Surgery, Asahikawa Medical University, Asahikawa, Japan
| | - Steve P. Evanko
- Matrix Biology Program, Benaroya Research Institute, Seattle, WA, United States of America
| | - Matthijs S. Ruiter
- Cardiovascular Tissue Engineering Unit—Centro Cardiologico Monzino, IRCCS, Via Parea, 4, Milan, Italy
| | - Marco Piola
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Alban Longchamp
- Department of Vascular Surgery, CHUV | Lausanne University Hospital, Lausanne, Switzerland
| | - Maurizio Pesce
- Cardiovascular Tissue Engineering Unit—Centro Cardiologico Monzino, IRCCS, Via Parea, 4, Milan, Italy
| | - Monica Soncini
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Sébastien Deglise
- Department of Vascular Surgery, CHUV | Lausanne University Hospital, Lausanne, Switzerland
| | - Gianfranco B. Fiore
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | | | - Tannin A. Schmidt
- Biomedical Engineering Department, School of Dental Medicine, University of Connecticut Health Center, Farmington, CT, United States of America
| | - Mark W. Majesky
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, United States of America
| | - Michael Sobel
- Division of Vascular Surgery, VA Puget Sound Health Care System, University of Washington, Seattle, WA, United States of America
| | - Thomas N. Wight
- Matrix Biology Program, Benaroya Research Institute, Seattle, WA, United States of America
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9
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Haefliger JA, Allagnat F, Hamard L, Le Gal L, Meda P, Nardelli-Haefliger D, Génot E, Alonso F. Targeting Cx40 (Connexin40) Expression or Function Reduces Angiogenesis in the Developing Mouse Retina. Arterioscler Thromb Vasc Biol 2017; 37:2136-2146. [PMID: 28982669 DOI: 10.1161/atvbaha.117.310072] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 09/20/2017] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Cx40 (Connexin40) forms intercellular channels that coordinate the electric conduction in the heart and the vasomotor tone in large vessels. The protein was shown to regulate tumoral angiogenesis; however, whether Cx40 also contributes to physiological angiogenesis is still unknown. APPROACH AND RESULTS Here, we show that Cx40 contributes to physiological angiogenesis. Genetic deletion of Cx40 leads to a reduction in vascular growth and capillary density in the neovascularization model of the mouse neonatal retina. At the angiogenic front, vessel sprouting is reduced, and the mural cells recruited along the sprouts display an altered phenotype. These alterations can be attributed to disturbed endothelial cell functions as selective reexpression of Cx40 in these cells restores normal angiogenesis. In vitro, targeting Cx40 in microvascular endothelial cells, by silencing its expression or by blocking gap junction channels, decreases their proliferation. Moreover, loss of Cx40 in these cells also increases their release of PDGF (platelet-derived growth factor) and promotes the chemoattraction of mural cells. In vivo, an intravitreal injection of a Cx40 inhibitory peptide, phenocopies the loss of Cx40 in the retinal vasculature of wild-type mice. CONCLUSIONS Collectively, our data show that endothelial Cx40 contributes to the early stages of physiological angiogenesis in the developing retina, by regulating vessel growth and maturation. Cx40 thus represents a novel therapeutic target for treating pathological ocular angiogenesis.
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Affiliation(s)
- Jacques-Antoine Haefliger
- From the Department of Medicine (J.-A.H., F.A., L.H., L.L.G., F.A.) and Department of Urology (D.N.H.), Lausanne University Hospital, Switzerland; Department of Cell Physiology and Metabolism, University of Geneva Medical Center, Switzerland (P.M.); and Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, France (E.G., F.A.).
| | - Florent Allagnat
- From the Department of Medicine (J.-A.H., F.A., L.H., L.L.G., F.A.) and Department of Urology (D.N.H.), Lausanne University Hospital, Switzerland; Department of Cell Physiology and Metabolism, University of Geneva Medical Center, Switzerland (P.M.); and Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, France (E.G., F.A.)
| | - Lauriane Hamard
- From the Department of Medicine (J.-A.H., F.A., L.H., L.L.G., F.A.) and Department of Urology (D.N.H.), Lausanne University Hospital, Switzerland; Department of Cell Physiology and Metabolism, University of Geneva Medical Center, Switzerland (P.M.); and Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, France (E.G., F.A.)
| | - Loïc Le Gal
- From the Department of Medicine (J.-A.H., F.A., L.H., L.L.G., F.A.) and Department of Urology (D.N.H.), Lausanne University Hospital, Switzerland; Department of Cell Physiology and Metabolism, University of Geneva Medical Center, Switzerland (P.M.); and Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, France (E.G., F.A.)
| | - Paolo Meda
- From the Department of Medicine (J.-A.H., F.A., L.H., L.L.G., F.A.) and Department of Urology (D.N.H.), Lausanne University Hospital, Switzerland; Department of Cell Physiology and Metabolism, University of Geneva Medical Center, Switzerland (P.M.); and Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, France (E.G., F.A.)
| | - Denise Nardelli-Haefliger
- From the Department of Medicine (J.-A.H., F.A., L.H., L.L.G., F.A.) and Department of Urology (D.N.H.), Lausanne University Hospital, Switzerland; Department of Cell Physiology and Metabolism, University of Geneva Medical Center, Switzerland (P.M.); and Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, France (E.G., F.A.)
| | - Elisabeth Génot
- From the Department of Medicine (J.-A.H., F.A., L.H., L.L.G., F.A.) and Department of Urology (D.N.H.), Lausanne University Hospital, Switzerland; Department of Cell Physiology and Metabolism, University of Geneva Medical Center, Switzerland (P.M.); and Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, France (E.G., F.A.)
| | - Florian Alonso
- From the Department of Medicine (J.-A.H., F.A., L.H., L.L.G., F.A.) and Department of Urology (D.N.H.), Lausanne University Hospital, Switzerland; Department of Cell Physiology and Metabolism, University of Geneva Medical Center, Switzerland (P.M.); and Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, France (E.G., F.A.).
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10
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Allagnat F, Dubuis C, Lambelet M, Le Gal L, Alonso F, Corpataux JM, Déglise S, Haefliger JA. Connexin37 reduces smooth muscle cell proliferation and intimal hyperplasia in a mouse model of carotid artery ligation. Cardiovasc Res 2017; 113:805-816. [PMID: 28449099 DOI: 10.1093/cvr/cvx079] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 04/20/2017] [Indexed: 12/11/2022] Open
Abstract
AIMS Intimal hyperplasia (IH) is an abnormal response to vessel injury characterized by the dedifferentiation, migration, and proliferation of quiescent vascular smooth muscle cells (VSMC) to form a neointima layer. Vascular connexins (Cx) are involved in the pathophysiology of various vascular diseases, and Cx43, the main Cx expressed in VSMC, has been shown to promote VSMC proliferation and IH. The aim of this study was to investigate the participation of another Cx, namely Cx37, in the formation of the neointima layer. METHODS AND RESULTS Wild-type (WT) and Cx37-deficient (Cx37-/-) C57BL/6J mice were subjected to carotid artery ligation (CAL), a model of vessel injury and IH. The neointima developed linearly in WT until 28 days post surgery. In contrast, the neointima layer was almost absent 14 days after surgery in Cx37-/- mice, and twice as more developed after 28 days compared to WT mice. This large neointima formation correlated with a two-fold increase in cell proliferation in the media and neointima regions between 14 and 28 days in Cx37-/- mice compared to WT mice. The CAL triggered Cx43 overexpression in the media and neointima layers of ligated carotids in WT mice, and selectively up-regulated Cx37 expression in the media layer, but not in the neointima layer. The de novo expression of Cx37 in human primary VSMC reduced cell proliferation and P-Akt levels, in association with lower Cx43 levels, whereas Cx43 overexpression increased P-Akt levels. CONCLUSION The presence of Cx37 in the media layer of injured arteries restrains VSMC proliferation and limits the development of IH, presumably by interfering with the pro-proliferative effect of Cx43 and the Akt pathway.
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MESH Headings
- Aged
- Animals
- Carotid Arteries/metabolism
- Carotid Arteries/pathology
- Carotid Arteries/surgery
- Carotid Artery Injuries/genetics
- Carotid Artery Injuries/metabolism
- Carotid Artery Injuries/pathology
- Carotid Stenosis/genetics
- Carotid Stenosis/metabolism
- Carotid Stenosis/pathology
- Cell Proliferation
- Cells, Cultured
- Connexin 43/metabolism
- Connexins/deficiency
- Connexins/genetics
- Connexins/metabolism
- Disease Models, Animal
- Female
- Humans
- Hyperplasia
- Ligation
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Neointima
- Phosphorylation
- Proto-Oncogene Proteins c-akt/metabolism
- Signal Transduction
- Time Factors
- Gap Junction alpha-4 Protein
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Affiliation(s)
- Florent Allagnat
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Céline Dubuis
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Martine Lambelet
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Loïc Le Gal
- Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV), Laboratory of Experimental Medicine, c/o Department of Physiology, Bugnon 7a, 1005 Lausanne, Switzerland
| | - Florian Alonso
- Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV), Laboratory of Experimental Medicine, c/o Department of Physiology, Bugnon 7a, 1005 Lausanne, Switzerland
| | - Jean-Marc Corpataux
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Sébastien Déglise
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Jacques-Antoine Haefliger
- Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV), Laboratory of Experimental Medicine, c/o Department of Physiology, Bugnon 7a, 1005 Lausanne, Switzerland
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11
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Mylonaki I, Allémann É, Saucy F, Haefliger JA, Delie F, Jordan O. Perivascular medical devices and drug delivery systems: Making the right choices. Biomaterials 2017; 128:56-68. [PMID: 28288349 DOI: 10.1016/j.biomaterials.2017.02.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 02/13/2017] [Accepted: 02/26/2017] [Indexed: 12/31/2022]
Abstract
Perivascular medical devices and perivascular drug delivery systems are conceived for local application around a blood vessel during open vascular surgery. These systems provide mechanical support and/or pharmacological activity for the prevention of intimal hyperplasia following vessel injury. Despite abundant reports in the literature and numerous clinical trials, no efficient perivascular treatment is available. In this review, the existing perivascular medical devices and perivascular drug delivery systems, such as polymeric gels, meshes, sheaths, wraps, matrices, and metal meshes, are jointly evaluated. The key criteria for the design of an ideal perivascular system are identified. Perivascular treatments should have mechanical specifications that ensure system localization, prolonged retention and adequate vascular constriction. From the data gathered, it appears that a drug is necessary to increase the efficacy of these systems. As such, the release kinetics of pharmacological agents should match the development of the pathology. A successful perivascular system must combine these optimized pharmacological and mechanical properties to be efficient.
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Affiliation(s)
- Ioanna Mylonaki
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, rue Michel Servet 1, CH-1211 Geneva 4, Switzerland
| | - Éric Allémann
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, rue Michel Servet 1, CH-1211 Geneva 4, Switzerland
| | - François Saucy
- Department of Vascular Surgery, Lausanne University Hospital, rue du Bugnon 46, CH-1011 Lausanne, Switzerland
| | - Jacques-Antoine Haefliger
- Department of Vascular Surgery, Lausanne University Hospital, rue du Bugnon 46, CH-1011 Lausanne, Switzerland
| | - Florence Delie
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, rue Michel Servet 1, CH-1211 Geneva 4, Switzerland
| | - Olivier Jordan
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, rue Michel Servet 1, CH-1211 Geneva 4, Switzerland.
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12
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Abstract
Efficient cell communication is a prerequisite for the coordinated function of tissues and organs. In vertebrates, this communication is mediated by a variety of mechanisms, including the exchange of molecules between cells, and between cells and the extracellular medium, via membrane channels made of connexin and pannexin proteins. These channels are a necessary component of all human tissues. Here, we review the biological essentials of the connexin and pannexin families, and the roles of these proteins in the function of cells which are central to major human diseases. We then discuss how connexins and pannexins participate in human pathology, and the clinical perspectives that this knowledge opens.
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Affiliation(s)
- Paolo Meda
- Département de Physiologie Cellulaire et Métabolisme, Université de Genève, Genève, Switzerland
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13
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Mylonaki I, Strano F, Deglise S, Allémann E, Alonso F, Corpataux JM, Dubuis C, Haefliger JA, Jordan O, Saucy F, Delie F. Perivascular sustained release of atorvastatin from a hydrogel-microparticle delivery system decreases intimal hyperplasia. J Control Release 2016; 232:93-102. [DOI: 10.1016/j.jconrel.2016.04.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 04/13/2016] [Accepted: 04/14/2016] [Indexed: 12/26/2022]
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14
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Longchamp A, Mirabella T, Hine C, Brace LE, Knudsen N, Treviño-Villarreal JH, Mejia P, Tao M, Sharma G, Wang R, Corpataux JM, Haefliger JA, Ahn KH, Lee CH, Chen C, Ozaki CK, Mitchell JR. Abstract 178: Angiogenesis is Triggered by Nutrient Deprivation via Gcn2/atf4-dependent Regulation of Vegf and H2s Production. Arterioscler Thromb Vasc Biol 2016. [DOI: 10.1161/atvb.36.suppl_1.178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective:
Angiogenesis is crucial to maintain tissue homeostasis under nutrient and oxygen deprivation (ischemia). Although considerable evidence supports that angiogenesis is regulated by hypoxia-HIF1α induction of vascular endothelial growth factor (VEGF), the role of nutrient deprivation in angiogenesis is poorly defined.
Approach and Results:
We report that nutrient deprivation in the form of dietary sulfur amino acid restriction (Methionine/cysteine Restriction; MR) promotes VEGF expression and functional growth of new capillaries in skeletal muscle of mice (Fig.1 A, B). This occurred independently of hypoxia or HIF1α, but instead required the amino acid-sensing eIF2α kinase GCN2 and the transcription factor ATF4 (Fig. 1C). In addition to increased VEGF, nutrient deprivation boosted production of the pro-angiogenic gas hydrogen sulfide (H
2
S) via increased GCN2/ATF4-dependent expression of the H
2
S-generating enzyme cystathionine-gamma-lyase (CGL). The genetic requirement for CGL in angiogenesis triggered by nutrient deprivation, exercise or local VEGF overexpression, as well as the ability of local CGL overexpression to promote angiogenesis in vivo, revealed the critical importance of CGL-derived H
2
S in angiogenesis (Fig. 1D). Finally, plasma H
2
S was reduced in patients with vascular disease (versus non-diseased age-matched controls), and correlated with 2-year survival following vascular surgery (Fig.1 E, F).
Conclusions:
These data reveal a nutrient-sensing pathway targetable by diet as a previously unrecognized central regulator of VEGF expression and angiogenesis independent of canonical hypoxic signaling. This discovery points to novel dietary interventions and GCN2/ATF4/CGL/H
2
S-based strategies to manipulate angiogenesis.
Figure 1
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Affiliation(s)
- Alban Longchamp
- Genetic and Complex disease, Harvard Sch of Public Health, Boston, MA
| | | | - Christopher Hine
- Genetic and Complex disease, Harvard Sch of Public Health, Boston, MA
| | - Lear E. Brace
- Genetic and Complex disease, Harvard Sch of Public Health, Boston, MA
| | - Nelson Knudsen
- Genetic and Complex disease, Harvard Sch of Public Health, Boston, MA
| | | | - Pedro Mejia
- Genetic and Complex disease, Harvard Sch of Public Health, Boston, MA
| | - Ming Tao
- Surgery and the Heart and Vascular Cntr, Brigham and Women s hospital, Boston, MA
| | - Gaurav Sharma
- surgery and the Heart and Vascular Cntr, Brigham and Women s hospital, Boston, MA
| | - Rui Wang
- Cardiovascular and Metabolic Rsch Unit, Laurentian Univ, Sudbury, Canada
| | | | | | - Kyo Han Ahn
- department of Chemistry, Cntr for Electro-Photo Behaviors in Advanced Molecular Systems, ,, Nam-Gu, Korea, Republic of
| | - Chih-Hao Lee
- Genetic and Complex disease, Harvard Sch of Public Health, Boston, MA
| | | | - Charles Keith Ozaki
- Surgery and the Heart and Vascular Cntr, Brigham and Women s hospital, Boston, MA
| | - James R. Mitchell
- Genetic and Complex disease, Harvard Sch of Public Health, Boston, MA
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15
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Alonso F, Domingos-Pereira S, Le Gal L, Derré L, Meda P, Jichlinski P, Nardelli-Haefliger D, Haefliger JA. Targeting endothelial connexin40 inhibits tumor growth by reducing angiogenesis and improving vessel perfusion. Oncotarget 2016; 7:14015-28. [PMID: 26883111 PMCID: PMC4924695 DOI: 10.18632/oncotarget.7370] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 01/29/2016] [Indexed: 01/09/2023] Open
Abstract
Endothelial connexin40 (Cx40) contributes to regulate the structure and function of vessels. We have examined whether the protein also modulates the altered growth of vessels in tumor models established in control mice (WT), mice lacking Cx40 (Cx40-/-), and mice expressing the protein solely in endothelial cells (Tie2-Cx40). Tumoral angiogenesis and growth were reduced, whereas vessel perfusion, smooth muscle cell (SMC) coverage and animal survival were increased in Cx40-/- but not Tie2-Cx40 mice, revealing a critical involvement of endothelial Cx40 in transformed tissues independently of the hypertensive status of Cx40-/- mice. As a result, Cx40-/- mice bearing tumors survived significantly longer than corresponding controls, including after a cytotoxic administration. Comparable observations were made in WT mice injected with a peptide targeting Cx40, supporting the Cx40 involvement. This involvement was further confirmed in the absence of Cx40 or by peptide-inhibition of this connexin in aorta-sprouting, matrigel plug and SMC migration assays, and associated with a decreased expression of the phosphorylated form of endothelial nitric oxide synthase. The data identify Cx40 as a potential novel target in cancer treatment.
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MESH Headings
- Animals
- Aorta/pathology
- Apoptosis
- Biomarkers, Tumor/metabolism
- Blood Vessels/physiology
- Cell Proliferation
- Connexins/antagonists & inhibitors
- Connexins/metabolism
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Female
- Humans
- Lung Neoplasms/blood supply
- Lung Neoplasms/pathology
- Lung Neoplasms/prevention & control
- Melanoma, Experimental/blood supply
- Melanoma, Experimental/pathology
- Melanoma, Experimental/prevention & control
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Neoplasm Invasiveness
- Neovascularization, Pathologic/prevention & control
- Perfusion
- Tumor Cells, Cultured
- Urinary Bladder Neoplasms/blood supply
- Urinary Bladder Neoplasms/pathology
- Urinary Bladder Neoplasms/prevention & control
- Gap Junction alpha-5 Protein
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Affiliation(s)
- Florian Alonso
- Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | | | - Loïc Le Gal
- Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | - Laurent Derré
- Department of Urology, Lausanne University Hospital, Lausanne, Switzerland
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, University of Geneva, Medical Center, Geneva, Switzerland
| | - Patrice Jichlinski
- Department of Urology, Lausanne University Hospital, Lausanne, Switzerland
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16
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Cigliola V, Populaire C, Pierri CL, Deutsch S, Haefliger JA, Fadista J, Lyssenko V, Groop L, Rueedi R, Thorel F, Herrera PL, Meda P. A Variant of GJD2, Encoding for Connexin 36, Alters the Function of Insulin Producing β-Cells. PLoS One 2016; 11:e0150880. [PMID: 26959991 PMCID: PMC4784816 DOI: 10.1371/journal.pone.0150880] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 02/20/2016] [Indexed: 01/16/2023] Open
Abstract
Signalling through gap junctions contributes to control insulin secretion and, thus, blood glucose levels. Gap junctions of the insulin-producing β-cells are made of connexin 36 (Cx36), which is encoded by the GJD2 gene. Cx36-null mice feature alterations mimicking those observed in type 2 diabetes (T2D). GJD2 is also expressed in neurons, which share a number of common features with pancreatic β-cells. Given that a synonymous exonic single nucleotide polymorphism of human Cx36 (SNP rs3743123) associates with altered function of central neurons in a subset of epileptic patients, we investigated whether this SNP also caused alterations of β-cell function. Transfection of rs3743123 cDNA in connexin-lacking HeLa cells resulted in altered formation of gap junction plaques and cell coupling, as compared to those induced by wild type (WT) GJD2 cDNA. Transgenic mice expressing the very same cDNAs under an insulin promoter revealed that SNP rs3743123 expression consistently lead to a post-natal reduction of islet Cx36 levels and β-cell survival, resulting in hyperglycemia in selected lines. These changes were not observed in sex- and age-matched controls expressing WT hCx36. The variant GJD2 only marginally associated to heterogeneous populations of diabetic patients. The data document that a silent polymorphism of GJD2 is associated with altered β-cell function, presumably contributing to T2D pathogenesis.
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Affiliation(s)
- Valentina Cigliola
- Department of Genetic Medicine and Development, University of Geneva Faculty of Medicine, Geneva, Switzerland
| | - Celine Populaire
- Centre Hospitalier Régional Universitaire Besançon, Besançon, France
| | - Ciro L. Pierri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Samuel Deutsch
- Joint Genome Institute, Walnut Creek, California, United States of America
| | | | - João Fadista
- Department of Clinical Sciences, Diabetes and Endocrinology, Lund University, Malmö, Sweden
| | - Valeriya Lyssenko
- Department of Clinical Sciences, Diabetes and Endocrinology, Lund University, Malmö, Sweden
- Steno Diabetes Center A/S, Gentofte, Denmark
| | - Leif Groop
- Department of Clinical Sciences, Diabetes and Endocrinology, Lund University, Malmö, Sweden
| | - Rico Rueedi
- Department of Computational Biology, University of Lausanne, Rue du Bugnon 27, 1011, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
| | - Fabrizio Thorel
- Department of Genetic Medicine and Development, University of Geneva Faculty of Medicine, Geneva, Switzerland
| | - Pedro Luis Herrera
- Department of Genetic Medicine and Development, University of Geneva Faculty of Medicine, Geneva, Switzerland
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, University of Geneva Faculty of Medicine, Geneva, Switzerland
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17
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Sabourin J, Le Gal L, Saurwein L, Haefliger JA, Raddatz E, Allagnat F. Store-operated Ca2+ Entry Mediated by Orai1 and TRPC1 Participates to Insulin Secretion in Rat β-Cells. J Biol Chem 2015; 290:30530-9. [PMID: 26494622 DOI: 10.1074/jbc.m115.682583] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Indexed: 11/06/2022] Open
Abstract
Store-operated Ca(2+) channels (SOCs) are voltage-independent Ca(2+) channels activated upon depletion of the endoplasmic reticulum Ca(2+) stores. Early studies suggest the contribution of such channels to Ca(2+) homeostasis in insulin-secreting pancreatic β-cells. However, their composition and contribution to glucose-stimulated insulin secretion (GSIS) remains unclear. In this study, endoplasmic reticulum Ca(2+) depletion triggered by acetylcholine (ACh) or thapsigargin stimulated the formation of a ternary complex composed of Orai1, TRPC1, and STIM1, the key proteins involved in the formation of SOCs. Ca(2+) imaging further revealed that Orai1 and TRPC1 are required to form functional SOCs and that these channels are activated by STIM1 in response to thapsigargin or ACh. Pharmacological SOCs inhibition or dominant negative blockade of Orai1 or TRPC1 using the specific pore mutants Orai1-E106D and TRPC1-F562A impaired GSIS in rat β-cells and fully blocked the potentiating effect of ACh on secretion. In contrast, pharmacological or dominant negative blockade of TRPC3 had no effect on extracellular Ca(2+) entry and GSIS. Finally, we observed that prolonged exposure to supraphysiological glucose concentration impaired SOCs function without altering the expression levels of STIM1, Orai1, and TRPC1. We conclude that Orai1 and TRPC1, which form SOCs regulated by STIM1, play a key role in the effect of ACh on GSIS, a process that may be impaired in type 2 diabetes.
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Affiliation(s)
- Jessica Sabourin
- From the INSERM, UMR S1180, Université Paris-Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France,
| | - Loïc Le Gal
- the Department of Medicine, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland, and
| | - Lisa Saurwein
- the Department of Medicine, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland, and
| | - Jacques-Antoine Haefliger
- the Department of Medicine, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland, and
| | - Eric Raddatz
- the Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland
| | - Florent Allagnat
- the Department of Medicine, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland, and
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18
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Longchamp A, Allagnat F, Alonso F, Kuppler C, Dubuis C, Ozaki CK, Mitchell JR, Berceli S, Corpataux JM, Déglise S, Haefliger JA. Connexin43 Inhibition Prevents Human Vein Grafts Intimal Hyperplasia. PLoS One 2015; 10:e0138847. [PMID: 26398895 PMCID: PMC4580578 DOI: 10.1371/journal.pone.0138847] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 09/04/2015] [Indexed: 12/12/2022] Open
Abstract
Venous bypass grafts often fail following arterial implantation due to excessive smooth muscle cells (VSMC) proliferation and consequent intimal hyperplasia (IH). Intercellular communication mediated by Connexins (Cx) regulates differentiation, growth and proliferation in various cell types. Microarray analysis of vein grafts in a model of bilateral rabbit jugular vein graft revealed Cx43 as an early upregulated gene. Additional experiments conducted using an ex-vivo human saphenous veins perfusion system (EVPS) confirmed that Cx43 was rapidly increased in human veins subjected ex-vivo to arterial hemodynamics. Cx43 knock-down by RNA interference, or adenoviral-mediated overexpression, respectively inhibited or stimulated the proliferation of primary human VSMC in vitro. Furthermore, Cx blockade with carbenoxolone or the specific Cx43 inhibitory peptide 43gap26 prevented the burst in myointimal proliferation and IH formation in human saphenous veins. Our data demonstrated that Cx43 controls proliferation and the formation of IH after arterial engraftment.
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Affiliation(s)
- Alban Longchamp
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois, Laboratory of Experimental Medicine, Lausanne, Switzerland
- Department of Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Florent Allagnat
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois, Laboratory of Experimental Medicine, Lausanne, Switzerland
| | - Florian Alonso
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois, Laboratory of Experimental Medicine, Lausanne, Switzerland
| | - Christopher Kuppler
- Malcom Randall Veterans Affairs Medical Center and the Division of Vascular and Endovascular Surgery, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Céline Dubuis
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois, Laboratory of Experimental Medicine, Lausanne, Switzerland
| | - Charles-Keith Ozaki
- Department of Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - James R. Mitchell
- Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Scott Berceli
- Malcom Randall Veterans Affairs Medical Center and the Division of Vascular and Endovascular Surgery, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Jean-Marc Corpataux
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois, Laboratory of Experimental Medicine, Lausanne, Switzerland
| | - Sébastien Déglise
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois, Laboratory of Experimental Medicine, Lausanne, Switzerland
| | - Jacques-Antoine Haefliger
- Department of Vascular Surgery, Centre Hospitalier Universitaire Vaudois, Laboratory of Experimental Medicine, Lausanne, Switzerland
- * E-mail:
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19
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Meens MJ, Alonso F, Le Gal L, Kwak BR, Haefliger JA. Endothelial Connexin37 and Connexin40 participate in basal but not agonist-induced NO release. Cell Commun Signal 2015; 13:34. [PMID: 26198171 PMCID: PMC4510910 DOI: 10.1186/s12964-015-0110-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 07/03/2015] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Connexin37 (Cx37) and Cx40 are crucial for endothelial cell-cell communication and homeostasis. Both connexins interact with endothelial nitric oxide synthase (eNOS). The exact contribution of these interactions to the regulation of vascular tone is unknown. RESULTS Cx37 and Cx40 were expressed in close proximity to eNOS at cell-cell interfaces of mouse aortic endothelial cells. Absence of Cx37 did not affect expression of Cx40 and a 50 % reduction of Cx40 in Cx40(+/-) aortas did not affect the expression of Cx37. However, absence of Cx40 was associated with reduced expression of Cx37. Basal NO release and the sensitivity for ACh were decreased in Cx37(-/-) and Cx40(-/-) aortas but not in Cx40(+/-) aortas. Moreover, ACh-induced release of constricting cyclooxygenase products was present in WT, Cx40(-/-) and Cx40(+/-) aortas but not in Cx37(-/-) aortas. Finally, agonist-induced NO-dependent relaxations and the sensitivity for exogenous NO were not affected by genotype. CONCLUSIONS Cx37 is more markedly involved in basal NO release, release of cyclooxygenase products and the regulation of the sensitivity for ACh as compared to Cx40.
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Affiliation(s)
- Merlijn J Meens
- Department of Pathology and Immunology, University of Geneva, 6th floor, 1 Rue Michel-Servet, 1211, Geneva, Switzerland.
- Department of Medical Specialties - Cardiology, University of Geneva, Geneva, Switzerland.
| | - Florian Alonso
- Department of Medicine, University Hospital, CHUV, Lausanne, Switzerland
| | - Loïc Le Gal
- Department of Medicine, University Hospital, CHUV, Lausanne, Switzerland
| | - Brenda R Kwak
- Department of Pathology and Immunology, University of Geneva, 6th floor, 1 Rue Michel-Servet, 1211, Geneva, Switzerland
- Department of Medical Specialties - Cardiology, University of Geneva, Geneva, Switzerland
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Martin D, Kim YH, Sever D, Mao CA, Haefliger JA, Grapin-Botton A. REST represses a subset of the pancreatic endocrine differentiation program. Dev Biol 2015; 405:316-27. [PMID: 26156633 DOI: 10.1016/j.ydbio.2015.07.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 07/01/2015] [Accepted: 07/02/2015] [Indexed: 12/20/2022]
Abstract
To contribute to devise successful beta-cell differentiation strategies for the cure of Type 1 diabetes we sought to uncover barriers that restrict endocrine fate acquisition by studying the role of the transcriptional repressor REST in the developing pancreas. Rest expression is prevented in neurons and in endocrine cells, which is necessary for their normal function. During development, REST represses a subset of genes in the neuronal differentiation program and Rest is down-regulated as neurons differentiate. Here, we investigate the role of REST in the differentiation of pancreatic endocrine cells, which are molecularly close to neurons. We show that Rest is widely expressed in pancreas progenitors and that it is down-regulated in differentiated endocrine cells. Sustained expression of REST in Pdx1(+) progenitors impairs the differentiation of endocrine-committed Neurog3(+) progenitors, decreases beta and alpha cell mass by E18.5, and triggers diabetes in adulthood. Conditional inactivation of Rest in Pdx1(+) progenitors is not sufficient to trigger endocrine differentiation but up-regulates a subset of differentiation genes. Our results show that the transcriptional repressor REST is active in pancreas progenitors where it gates the activation of part of the beta cell differentiation program.
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Affiliation(s)
- David Martin
- Swiss Institute for Experimental Cancer Research, Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Station 19, 1015 Lausanne, Switzerland
| | - Yung-Hae Kim
- DanStem, University of Copenhagen, 3B Blegdamsvej, DK-2200 Copenhagen N, Denmark
| | - Dror Sever
- DanStem, University of Copenhagen, 3B Blegdamsvej, DK-2200 Copenhagen N, Denmark
| | - Chai-An Mao
- Department of Systems Biology, The University of MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jacques-Antoine Haefliger
- Department of Medicine, Laboratory of Experimental Medicine, C/O Department of Physiology, Bugnon 7a, 1005 Lausanne, Switzerland
| | - Anne Grapin-Botton
- Swiss Institute for Experimental Cancer Research, Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Station 19, 1015 Lausanne, Switzerland; DanStem, University of Copenhagen, 3B Blegdamsvej, DK-2200 Copenhagen N, Denmark.
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Allagnat F, Alonso F, Corpataux JM, Haefliger JA, Deglise S. Abstract 489: Dual Role of Connexin37 in the Control of Vascular Inflammation and Smooth Muscle Cell Proliferation During Intimal Hyperplasia in Mice. Arterioscler Thromb Vasc Biol 2015. [DOI: 10.1161/atvb.35.suppl_1.489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
The long term patency of vascular interventions is plagued by restenosis due to intimal hyperplasia (IH). Intercellular communication mediated by gap junctions plays a key role in tissue homeostasis and we recently showed that the gap junction protein Connexin43 (Cx43) contributes to smooth muscle cell (SMC) proliferation and IH. We now hypothesized that vascular Cx37 also plays a role in vascular remodeling and IH.
Methods and Results:
WT and Cx37 deficient mice (Cx37-/-) were subjected to the carotid artery ligation model. In WT mice, the ligation resulted in IH formation, as evidence by the development of a SMC -rich neointima after two to four weeks. This remodeling correlated with a reduced Cx37 expression in the endothelium layer and an increased Cx37 expression in the media layer. Compared to WT mice, Cx37-/- mice displayed a delayed development of neointima due to reduced infiltration of CD45-positive immune cells. However, Cx37-/- mice displayed an accelerated SMC proliferation rate between two and four weeks post surgery, as evidence by the number of PCNA-positive cells. Cx37-/- mouse arteries overexpressed synthetic SMC markers. Finally, in primary human vein SMC, Cx37 overexpression reduced cell proliferation and migration.
Conclusions:
Cx37 plays a dual role in neointima formation following vascular injury. Cx37 promotes immune cell infiltration and inflammation in the vessel. On the other hand, Cx37 overexpression in SMC counteracts the proliferative role of Cx43. Thus, Cx37 may play both protective and harmful roles in IH.
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Abstract
Connexins (Cxs) and endothelial nitric oxide synthase (eNOS) contribute to the adaptation of endothelial and smooth muscle cells to hemodynamic changes. To decipher the in vivo interplay between these proteins, we studied Cx40-null mice, a model of renin-dependent hypertension which displays an altered endothelium-dependent relaxation of the aorta because of reduced eNOS levels. These mice, which were either untreated or subjected to the 1-kidney, 1-clip (1K1C) procedure, a model of volume-dependent hypertension, were compared with control mice submitted to either the 1K1C or the 2-kidney, 1-clip (2K1C) procedure, a model of renin-dependent hypertension. All operated mice became hypertensive and featured hypertrophy and altered Cx expression of the aorta. The combination of volume- and renin-dependent hypertension in Cx40-/- 1K1C mice raised blood pressure and cardiac weight index. Under these conditions, all aortas showed increased levels of Cx40 in endothelial cells and of both Cx37 and Cx45 in smooth muscle cells. In the wild-type 1K1C mice, the interactions between Cx40 and Cx37 with eNOS were enhanced, resulting in increased NO release. The Cx40-eNOS interaction could not be observed in mice lacking Cx40, which also featured decreased levels of eNOS. In these animals, the volume overload caused by the 1K1C procedure resulted in increased phosphorylation of eNOS and in a higher NO release. The findings provide evidence that Cx40 and Cx37 play an in vivo role in the regulation of eNOS.
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Affiliation(s)
- Loïc Le Gal
- From the Departments of Medicine (L.L.G., F.A., J.-A.H.) and Angiology (L.M.), Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland; and Department of Cell Physiology and Metabolism, University of Geneva, Medical Center, Geneva, Switzerland (P.M.)
| | - Florian Alonso
- From the Departments of Medicine (L.L.G., F.A., J.-A.H.) and Angiology (L.M.), Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland; and Department of Cell Physiology and Metabolism, University of Geneva, Medical Center, Geneva, Switzerland (P.M.)
| | - Lucia Mazzolai
- From the Departments of Medicine (L.L.G., F.A., J.-A.H.) and Angiology (L.M.), Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland; and Department of Cell Physiology and Metabolism, University of Geneva, Medical Center, Geneva, Switzerland (P.M.)
| | - Paolo Meda
- From the Departments of Medicine (L.L.G., F.A., J.-A.H.) and Angiology (L.M.), Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland; and Department of Cell Physiology and Metabolism, University of Geneva, Medical Center, Geneva, Switzerland (P.M.)
| | - Jacques-Antoine Haefliger
- From the Departments of Medicine (L.L.G., F.A., J.-A.H.) and Angiology (L.M.), Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland; and Department of Cell Physiology and Metabolism, University of Geneva, Medical Center, Geneva, Switzerland (P.M.).
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23
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Longchamp A, Allagnat F, Berard X, Alonso F, Haefliger JA, Deglise S, Corpataux JM. Procedure for human saphenous veins ex vivo perfusion and external reinforcement. J Vis Exp 2014:e52079. [PMID: 25350681 DOI: 10.3791/52079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The mainstay of contemporary therapies for extensive occlusive arterial disease is venous bypass graft. However, its durability is threatened by intimal hyperplasia (IH) that eventually leads to vessel occlusion and graft failure. Mechanical forces, particularly low shear stress and high wall tension, are thought to initiate and to sustain these cellular and molecular changes, but their exact contribution remains to be unraveled. To selectively evaluate the role of pressure and shear stress on the biology of IH, an ex vivo perfusion system (EVPS) was created to perfuse segments of human saphenous veins under arterial regimen (high shear stress and high pressure). Further technical innovations allowed the simultaneous perfusion of two segments from the same vein, one reinforced with an external mesh. Veins were harvested using a no-touch technique and immediately transferred to the laboratory for assembly in the EVPS. One segment of the freshly isolated vein was not perfused (control, day 0). The two others segments were perfused for up to 7 days, one being completely sheltered with a 4 mm (diameter) external mesh. The pressure, flow velocity, and pulse rate were continuously monitored and adjusted to mimic the hemodynamic conditions prevailing in the femoral artery. Upon completion of the perfusion, veins were dismounted and used for histological and molecular analysis. Under ex vivo conditions, high pressure perfusion (arterial, mean = 100 mm Hg) is sufficient to generate IH and remodeling of human veins. These alterations are reduced in the presence of an external polyester mesh.
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Affiliation(s)
- Alban Longchamp
- Department of Surgery, Brigham and Women's Hospital/Harvard Medical School;
| | - Florent Allagnat
- Laboratory of Experimental Medicine, Department of Medicine, CHUV University Hospital
| | - Xavier Berard
- Department of Vascular Surgery, Pellegrin Hospital, University of Bordeaux
| | - Florian Alonso
- Laboratory of Experimental Medicine, Department of Medicine, CHUV University Hospital
| | | | - Sébastien Deglise
- Department of Thoracic and Vascular Surgery, CHUV University Hospital
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Le Gal L, Alonso F, Wagner C, Germain S, Nardelli Haefliger D, Meda P, Haefliger JA. Restoration of connexin 40 (Cx40) in Renin-producing cells reduces the hypertension of Cx40 null mice. Hypertension 2014; 63:1198-204. [PMID: 24614215 DOI: 10.1161/hypertensionaha.113.02976] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Connexin 40 (Cx40) is expressed by the renin-producing cells (RSCs) of the kidneys and the endothelial cells of blood vessels. Cx40 null mice (Cx40(-/-)) feature a much increased renin synthesis and secretion, which results in chronic hypertension, and also display an altered endothelium-dependent relaxation of the aorta because of reduced eNOS levels and nitric oxide production. To discriminate the effect of Cx40 in renin secretion and vascular signaling, we targeted Cx40 to either the RSCs or the endothelial cells of Cx40 null mice. When compared with Cx40(-/-) controls, the animals expressing Cx40 in RSCs were less hypertensive and featured reduced renin levels, still numerous RSCs outside the wall of the afferent arterioles. In contrast, mice expressing Cx40 in the endothelial cells were as hypertensive as Cx40(-/-) mice, in spite of control levels of Cx37 and eNOS. Our data show that blood pressure is improved by restoration of Cx40 expression in RSCs but not in endothelial cells, stressing the prominent role of renin in the mouse hypertension linked to loss of Cx40.
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Affiliation(s)
- Loïc Le Gal
- Department of Medicine, Laboratory of Experimental Medicine, c/o Department of Physiology, Bugnon 7a, 1005 Lausanne, Switzerland.
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25
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Dubuis C, May L, Alonso F, Luca L, Mylonaki I, Meda P, Delie F, Jordan O, Déglise S, Corpataux JM, Saucy F, Haefliger JA. Atorvastatin-loaded hydrogel affects the smooth muscle cells of human veins. J Pharmacol Exp Ther 2013; 347:574-81. [PMID: 24071735 DOI: 10.1124/jpet.113.208769] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Intimal hyperplasia (IH) is the major cause of stenosis of vein grafts. Drugs such as statins prevent stenosis, but their systemic administration has limited effects. We developed a hyaluronic acid hydrogel matrix, which ensures a controlled release of atorvastatin (ATV) at the site of injury. The release kinetics demonstrated that 100% of ATV was released over 10 hours, independent of the loading concentration of the hydrogel. We investigated the effects of such a delivery on primary vascular smooth muscle cells isolated from human veins. ATV decreased the proliferation, migration, and passage of human smooth muscle cells (HSMCs) across a matrix barrier in a similar dose-dependent (5-10 µM) and time-dependent manner (24-72 hours), whether the drug was directly added to the culture medium or released from the hydrogel. Expression analysis of genes known to be involved in the development of IH demonstrated that the transcripts of both the gap junction protein connexin43 (Cx43) and plasminogen activator inhibitor-1 (PAI-1) were decreased after a 24-48-hour exposure to the hydrogel loaded with ATV, whereas the transcripts of the heme oxygenase (HO-1) and the inhibitor of tissue plasminogen activator were increased. At the protein level, Cx43, PAI-1, and metalloproteinase-9 expression were decreased, whereas HO-1 was upregulated in the presence of ATV. The data demonstrate that ATV released from a hydrogel has effects on HSMCs similar to the drug being freely dissolved in the environment.
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Affiliation(s)
- Céline Dubuis
- Department of Thoracic and Vascular Surgery, University Hospital, Laboratory of Experimental Medicine, Lausanne, Switzerland (C.D., L.M., F.A., S.D., J.-M.C., F.S., J.-A.H.); School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva, Switzerland (L.L., I.M., F.D., O.J.); and Department of Cell Physiology and Metabolism, University of Geneva, Medical Center, Geneva, Switzerland (P.M.)
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26
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Haefliger JA, Rohner-Jeanrenaud F, Caille D, Charollais A, Meda P, Allagnat F. Hyperglycemia downregulates Connexin36 in pancreatic islets via the upregulation of ICER-1/ICER-1γ. J Mol Endocrinol 2013; 51:49-58. [PMID: 23613279 DOI: 10.1530/jme-13-0054] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Channels formed by the gap junction protein Connexin36 (CX36) contribute to the proper control of insulin secretion. We previously demonstrated that chronic exposure to glucose decreases Cx36 levels in insulin-secreting cells in vitro. Here, we investigated whether hyperglycemia also regulates Cx36 in vivo. Using a model of continuous glucose infusion in adult rats, we showed that prolonged (24-48 h) hyperglycemia reduced the Cx36 gene Gjd2 mRNA levels in pancreatic islets. Accordingly, prolonged exposure to high glucose concentrations also reduced the expression and function of Cx36 in the rat insulin-producing INS-1E cell line. The glucose effect was blocked after inhibition of the cAMP/PKA pathway and was associated with an overexpression of the inducible cAMP early repressor ICER-1/ICER-1γ, which binds to a functional cAMP-response element in the promoter of the Cx36 gene Gjd2. The involvement of this repressor was further demonstrated using an antisense strategy of ICER-1 inhibition, which prevented glucose-induced downregulation of Cx36. The data indicate that chronic exposure to glucose alters the in vivo expression of Cx36 by the insulin-producing β-cells through ICER-1/ICER-1γ overexpression. This mechanism may contribute to the reduced glucose sensitivity and altered insulin secretion, which contribute to the pathophysiology of diabetes.
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Affiliation(s)
- Jacques-Antoine Haefliger
- Service of Internal Medicine, Department of Physiology, University Hospital Lausanne, Lausanne, Switzerland
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27
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Bérard X, Déglise S, Daculsi R, Delmond S, Bourget C, Saucy F, Corpataux JM, Haefliger JA, Midy D, Bordenave L. The influence of cannulation on metalloproteinase expression in venous aneurysm complicating vascular access arteriovenous fistula. Cardiovasc Pathol 2013. [DOI: 10.1016/j.carpath.2013.01.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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28
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Tawadros T, Alonso F, Jichlinski P, Clarke N, Calandra T, Haefliger JA, Roger T. Release of macrophage migration inhibitory factor by neuroendocrine-differentiated LNCaP cells sustains the proliferation and survival of prostate cancer cells. Endocr Relat Cancer 2013. [PMID: 23207293 DOI: 10.1530/erc-12-0286] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The acquisition of neuroendocrine (NE) characteristics by prostate cancer (PCa) cells is closely related to tumour progression and hormone resistance. The mechanisms by which NE cells influence PCa growth and progression are not fully understood. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine involved in oncogenic processes, and MIF serum levels correlate with aggressiveness of PCa. Here, we investigated the regulation and the functional consequences of MIF expression during NE transdifferentiation of PCa cells. NE differentiation (NED) of LNCaP cells, initiated either by increasing intracellular levels of cAMP or by culturing cells in an androgen-depleted medium, was associated with markedly increased MIF release. Yet, intracellular MIF protein and mRNA levels and MIF gene promoter activity decreased during NED of LNCaP cells, suggesting that NED favours MIF release despite decreasing MIF synthesis. Adenoviral-mediated forced MIF expression in NE-differentiated LNCaP cells increased cell proliferation without affecting the expression of NE markers. Addition of exogenous recombinant MIF to LNCaP and PC-3 cells stimulated the AKT and ERK1/2 signalling pathways, the expression of genes involved in PCa, as well as proliferation and resistance to paclitaxel and thapsigargin-induced apoptosis. Altogether, these data provide evidence that increased MIF release during NED in PCa may facilitate cancer progression or recurrence, especially following androgen deprivation. Thus, MIF could represent an attractive target for PCa therapy.
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Affiliation(s)
- Thomas Tawadros
- Service of Urology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Rue du Bugnon 46, Lausanne, Switzerland.
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Boittin FX, Alonso F, Le Gal L, Allagnat F, Bény JL, Haefliger JA. Connexins and M3 muscarinic receptors contribute to heterogeneous Ca(2+) signaling in mouse aortic endothelium. Cell Physiol Biochem 2013; 31:166-78. [PMID: 23407022 DOI: 10.1159/000343358] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Smooth muscle tone is controlled by Ca(2+) signaling in the endothelial layer. Mouse endothelial cells are interconnected by gap junctions made of Connexin40 (Cx40) and Cx37, which allow the exchange of signaling molecules to coordinate their activity. Here, we investigated the role of Cx40 in the endothelial Ca(2+) signaling of the mouse aorta. METHODS Ca(2+) imaging was performed on intact aortic endothelium from both wild type (Cx40+/+) and Connexin40-deficient (Cx40 -/-) mice. RESULTS Acetylcholine (ACh) induced early fast and high amplitude Ca(2+) transients in a fraction of endothelial cells expressing the M3 muscarinic receptors. Inhibition of intercellular communication using carbenoxolone or octanol fully blocked the propagation of ACh-induced Ca(2+) transients toward adjacent cells in WT and Cx40-/- mice. As compared to WT, Cx40-/- mice displayed a reduced propagation of ACh-induced Ca(2+) waves, indicating that Cx40 contributes to the spreading of Ca(2+) signals. The propagation of those Ca(2+) responses was not blocked by suramin, a blocker of purinergic ATP receptors, indicating that there is no paracrine effect of ATP release on the Ca(2+) waves. CONCLUSIONS Altogether our data show that Cx40 and Cx37 contribute to the propagation and amplification of the Ca(2+) signaling triggered by ACh in endothelial cells expressing the M3 muscarinic receptors.
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Affiliation(s)
- François-Xavier Boittin
- Department of Zoology and Animal Biology, Laboratory of Vascular Cell Physiology, University of Geneva, Geneva 4, Switzerland
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30
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Haefliger JA, Martin D, Favre D, Petremand Y, Mazzolai L, Abderrahmani A, Meda P, Waeber G, Allagnat F. Reduction of connexin36 content by ICER-1 contributes to insulin-secreting cells apoptosis induced by oxidized LDL particles. PLoS One 2013; 8:e55198. [PMID: 23383107 PMCID: PMC3559396 DOI: 10.1371/journal.pone.0055198] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 12/19/2012] [Indexed: 12/14/2022] Open
Abstract
Connexin36 (Cx36), a trans-membrane protein that forms gap junctions between insulin-secreting beta-cells in the Langerhans islets, contributes to the proper control of insulin secretion and beta-cell survival. Hypercholesterolemia and pro-atherogenic low density lipoproteins (LDL) contribute to beta-cell dysfunction and apoptosis in the context of Type 2 diabetes. We investigated the impact of LDL-cholesterol on Cx36 levels in beta-cells. As compared to WT mice, the Cx36 content was reduced in islets from hypercholesterolemic ApoE-/- mice. Prolonged exposure to human native (nLDL) or oxidized LDL (oxLDL) particles decreased the expression of Cx36 in insulin secreting cell-lines and isolated rodent islets. Cx36 down-regulation was associated with overexpression of the inducible cAMP early repressor (ICER-1) and the selective disruption of ICER-1 prevented the effects of oxLDL on Cx36 expression. Oil red O staining and Plin1 expression levels suggested that oxLDL were less stored as neutral lipid droplets than nLDL in INS-1E cells. The lipid beta-oxidation inhibitor etomoxir enhanced oxLDL-induced apoptosis whereas the ceramide synthesis inhibitor myriocin partially protected INS-1E cells, suggesting that oxLDL toxicity was due to impaired metabolism of the lipids. ICER-1 and Cx36 expressions were closely correlated with oxLDL toxicity. Cx36 knock-down in INS-1E cells or knock-out in primary islets sensitized beta-cells to oxLDL-induced apoptosis. In contrast, overexpression of Cx36 partially protected INS-1E cells against apoptosis. These data demonstrate that the reduction of Cx36 content in beta-cells by oxLDL particles is mediated by ICER-1 and contributes to oxLDL-induced beta-cell apoptosis.
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Affiliation(s)
| | - David Martin
- Service of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Dimitri Favre
- Department of Cellular Biology and Morphology, University of Lausanne, Lausanne, Switzerland
| | - Yannick Petremand
- Department of Physiology, University of Lausanne, Lausanne, Switzerland
| | - Lucia Mazzolai
- Service of Vascular Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Amar Abderrahmani
- European Genomic Institute for Diabetes, UMR 8199, University of Lille Nord de France, Lille, France
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, University Medical Center, Geneva, Switzerland
| | - Gérard Waeber
- Service of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Florent Allagnat
- Service of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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31
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Berard X, Déglise S, Alonso F, Saucy F, Meda P, Bordenave L, Corpataux JM, Haefliger JA. Role of hemodynamic forces in the ex vivo arterialization of human saphenous veins. J Vasc Surg 2013; 57:1371-82. [PMID: 23351647 DOI: 10.1016/j.jvs.2012.09.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/31/2012] [Accepted: 09/10/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Human saphenous vein grafts are one of the salvage bypass conduits when endovascular procedures are not feasible or fail. Understanding the remodeling process that venous grafts undergo during exposure to arterial conditions is crucial to improve their patency, which is often compromised by intimal hyperplasia. The precise role of hemodynamic forces such as shear stress and arterial pressure in this remodeling is not fully characterized. The aim of this study was to determine the involvement of arterial shear stress and pressure on vein wall remodeling and to unravel the underlying molecular mechanisms. METHODS An ex vivo vein support system was modified for chronic (up to 1 week), pulsatile perfusion of human saphenous veins under controlled conditions that permitted the separate control of arterial shear stress and different arterial pressure (7 mm Hg or 70 mm Hg). RESULTS Veins perfused for 7 days under high pressure (70 mm Hg) underwent significant development of a neointima compared with veins exposed to low pressure (7 mm Hg). These structural changes were associated with altered expression of several molecular markers. Exposure to an arterial shear stress under low pressure increased the expression of matrix metalloproteinase (MMP)-2 and MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1 at the transcript, protein, and activity levels. This increase was enhanced by high pressure, which also increased TIMP-2 protein expression despite decreased levels of the cognate transcript. In contrast, the expression of plasminogen activator inhibitor-1 increased with shear stress but was not modified by pressure. Levels of the venous marker Eph-B4 were decreased under arterial shear stress, and levels of the arterial marker Ephrin-B2 were downregulated under high-pressure conditions. CONCLUSIONS This model is a valuable tool to identify the role of hemodynamic forces and to decipher the molecular mechanisms leading to failure of human saphenous vein grafts. Under ex vivo conditions, arterial perfusion is sufficient to activate the remodeling of human veins, a change that is associated with the loss of specific vein markers. Elevation of pressure generates intimal hyperplasia, even though veins do not acquire arterial markers. CLINICAL RELEVANCE The pathological remodeling of the venous wall, which leads to stenosis and ultimately graft failure, is the main limiting factor of human saphenous vein graft bypass. This remodeling is due to the hemodynamic adaptation of the vein to the arterial environment and cannot be prevented by conventional therapy. To develop a more targeted therapy, a better understanding of the molecular mechanisms involved in intimal hyperplasia is essential, which requires the development of ex vivo models of chronic perfusion of human veins.
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Affiliation(s)
- Xavier Berard
- Department of Vascular Surgery, Pellegrin Hospital, University of Bordeaux, Bordeaux, France
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Martin D, Allagnat F, Gesina E, Caille D, Gjinovci A, Waeber G, Meda P, Haefliger JA. Specific silencing of the REST target genes in insulin-secreting cells uncovers their participation in beta cell survival. PLoS One 2012; 7:e45844. [PMID: 23029270 PMCID: PMC3447792 DOI: 10.1371/journal.pone.0045844] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 08/24/2012] [Indexed: 12/22/2022] Open
Abstract
The absence of the transcriptional repressor RE-1 Silencing Transcription Factor (REST) in insulin-secreting beta cells is a major cue for the specific expression of a large number of genes. These REST target genes were largely ascribed to a function of neurotransmission in a neuronal context, whereas their role in pancreatic beta cells has been poorly explored. To identify their functional significance, we have generated transgenic mice expressing REST in beta cells (RIP-REST mice), and previously discovered that REST target genes are essential to insulin exocytosis. Herein we characterized a novel line of RIP-REST mice featuring diabetes. In diabetic RIP-REST mice, high levels of REST were associated with postnatal beta cell apoptosis, which resulted in gradual beta cell loss and sustained hyperglycemia in adults. Moreover, adenoviral REST transduction in INS-1E cells led to increased cell death under control conditions, and sensitized cells to death induced by cytokines. Screening for REST target genes identified several anti-apoptotic genes bearing the binding motif RE-1 that were downregulated upon REST expression in INS-1E cells, including Gjd2, Mapk8ip1, Irs2, Ptprn, and Cdk5r2. Decreased levels of Cdk5r2 in beta cells of RIP-REST mice further confirmed that it is controlled by REST, in vivo. Using siRNA-mediated knock-down in INS-1E cells, we showed that Cdk5r2 protects beta cells against cytokines and palmitate-induced apoptosis. Together, these data document that a set of REST target genes, including Cdk5r2, is important for beta cell survival.
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Affiliation(s)
- David Martin
- Service of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Florent Allagnat
- Service of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Emilie Gesina
- Ecole Polytechnique Fédérale de Lausanne, Faculté des Sciences de la Vie, Lausanne, Switzerland
| | - Dorothee Caille
- Department of Cell Physiology and Metabolism, University Medical Center, Geneva, Switzerland
| | - Asllan Gjinovci
- Department of Cell Physiology and Metabolism, University Medical Center, Geneva, Switzerland
| | - Gerard Waeber
- Service of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, University Medical Center, Geneva, Switzerland
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33
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Nlend RN, Aït-Lounis A, Allagnat F, Cigliola V, Charollais A, Reith W, Haefliger JA, Meda P. Cx36 is a target of Beta2/NeuroD1, which associates with prenatal differentiation of insulin-producing β cells. J Membr Biol 2012; 245:263-73. [PMID: 22729650 DOI: 10.1007/s00232-012-9447-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 06/01/2012] [Indexed: 10/28/2022]
Abstract
The insulin-producing β cells of pancreatic islets are coupled by connexin36 (Cx36) channels. To investigate what controls the expression of this connexin, we have investigated its pattern during mouse pancreas development, and the influence of three transcription factors that are critical for β-cell development and differentiation. We show that (1) the Cx36 gene (Gjd2) is activated early in pancreas development and is markedly induced at the time of the surge of the transcription factors that determine β-cell differentiation; (2) the cognate protein is detected about a week later and is selectively expressed by β cells throughout the prenatal development of mouse pancreas; (3) a 2-kbp fragment of the Gjd2 promoter, which contains three E boxes for the binding of the bHLH factor Beta2/NeuroD1, ensures the expression of Cx36 by β cells; and (4) Beta2/NeuroD1 binds to these E boxes and, in the presence of the E47 ubiquitous cofactor, transactivates the Gjd2 promoter. The data identify Cx36 as a novel early marker of β cells and as a target of Beta2/NeuroD1, which is essential for β-cell development and differentiation.
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Affiliation(s)
- Rachel Nlend Nlend
- Department of Cell Physiology and Metabolism, University of Geneva, CMU, 1 Rue Michel Servet CH- 1211, Geneva 4, Switzerland
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34
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Allagnat F, Fukaya M, Nogueira TC, Delaroche D, Welsh N, Marselli L, Marchetti P, Haefliger JA, Eizirik DL, Cardozo AK. C/EBP homologous protein contributes to cytokine-induced pro-inflammatory responses and apoptosis in β-cells. Cell Death Differ 2012; 19:1836-46. [PMID: 22653339 DOI: 10.1038/cdd.2012.67] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Induction of the C/EBP homologous protein (CHOP) is considered a key event for endoplasmic reticulum (ER) stress-mediated apoptosis. Type 1 diabetes (T1D) is characterized by an autoimmune destruction of the pancreatic β-cells. Pro-inflammatory cytokines are early mediators of β-cell death in T1D. Cytokines induce ER stress and CHOP overexpression in β-cells, but the role for CHOP overexpression in cytokine-induced β-cell apoptosis remains controversial. We presently observed that CHOP knockdown (KD) prevents cytokine-mediated degradation of the anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2) and myeloid cell leukemia sequence 1 (Mcl-1), thereby decreasing the cleavage of executioner caspases 9 and 3, and apoptosis. Nuclear factor-κB (NF-κB) is a crucial transcription factor regulating β-cell apoptosis and inflammation. CHOP KD resulted in reduced cytokine-induced NF-κB activity and expression of key NF-κB target genes involved in apoptosis and inflammation, including iNOS, FAS, IRF-7, IL-15, CCL5 and CXCL10. This was due to decreased IκB degradation and p65 translocation to the nucleus. The present data suggest that CHOP has a dual role in promoting β-cell death: (1) CHOP directly contributes to cytokine-induced β-cell apoptosis by promoting cytokine-induced mitochondrial pathways of apoptosis; and (2) by supporting the NF-κB activation and subsequent cytokine/chemokine expression, CHOP may contribute to apoptosis and the chemo attraction of mononuclear cells to the islets during insulitis.
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Affiliation(s)
- F Allagnat
- Laboratoire de Médecine Expérimentale, Université Libre de Bruxelles, Brussels, Belgium
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35
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Pfenniger A, van der Laan SW, Foglia B, Dunoyer-Geindre S, Haefliger JA, Winnik S, Mach F, Pasterkamp G, James RW, Kwak BR. Lack of association between connexin40 polymorphisms and coronary artery disease. Atherosclerosis 2012; 222:148-53. [PMID: 22405441 DOI: 10.1016/j.atherosclerosis.2012.01.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 01/23/2012] [Accepted: 01/30/2012] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Cx40 is a gap junction protein important for cell-cell communication in the endothelium. Polymorphisms in the promoter region of the human Cx40 gene, -44G>A and +71A>G, were shown to reduce Cx40 transcription by half. As mice with an endothelial-specific deletion of Cx40 are more susceptible to atherosclerosis, this study was designed to discover a correlation between these polymorphisms and atherosclerosis in European populations. METHODS AND RESULTS 803 patients referred to the Geneva University Hospitals for elective coronary angiography were divided according to the number of significantly stenosed vessels (from 0 to 3) and were genotyped for the Cx40 polymorphisms. Genotype distribution in the control group was -44GG/+71AA=59.8%, -44AG/+71AG=35.1% and -44AA/+71GG=5.2%. Surprisingly, this distribution was similar in the CAD group, with -44GG/+71AA=58.5%, -44AG/+71AG=37.6% and -44AA/+71GG=3.8% (p=0.67). Moreover, no significant association between histological carotid plaque composition of culprit lesions and Cx40 polymorphisms could be detected in 583 Dutch patients of the Athero-Express study. CONCLUSIONS Despite a clear antiatherogenic role of Cx40 in mice, our study could not detect an association of Cx40 promoter polymorphisms and CAD in human. Moreover, a correlation with atherosclerotic plaque stability or hypertension could not be demonstrated either. Connexin polymorphisms affecting channel function may be of greater importance for cardiovascular disease than polymorphisms affecting the expression level of the protein.
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Affiliation(s)
- Anna Pfenniger
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Switzerland.
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36
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Halidi N, Alonso F, Burt JM, Bény JL, Haefliger JA, Meister JJ. Intercellular calcium waves in primary cultured rat mesenteric smooth muscle cells are mediated by connexin43. Cell Commun Adhes 2012; 19:25-37. [PMID: 22642233 PMCID: PMC3804248 DOI: 10.3109/15419061.2012.690792] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Intercellular Ca(2+) wave propagation between vascular smooth muscle cells (SMCs) is associated with the propagation of contraction along the vessel. Here, we characterize the involvement of gap junctions (GJs) in Ca(2+) wave propagation between SMCs at the cellular level. Gap junctional communication was assessed by the propagation of intercellular Ca(2+) waves and the transfer of Lucifer Yellow in A7r5 cells, primary rat mesenteric SMCs (pSMCs), and 6B5N cells, a clone of A7r5 cells expressing higher connexin43 (Cx43) to Cx40 ratio. Mechanical stimulation induced an intracellular Ca(2+) wave in pSMC and 6B5N cells that propagated to neighboring cells, whereas Ca(2+) waves in A7r5 cells failed to progress to neighboring cells. We demonstrate that Cx43 forms the functional GJs that are involved in mediating intercellular Ca(2+) waves and that co-expression of Cx40 with Cx43, depending on their expression ratio, may interfere with Cx43 GJ formation, thus altering junctional communication.
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Affiliation(s)
- Nadia Halidi
- Laboratory of Cell Biophysics, Ecole Polytechnique Fédérale de Lausanne, Switzerland.
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37
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Klee P, Allagnat F, Pontes H, Cederroth M, Charollais A, Caille D, Britan A, Haefliger JA, Meda P. Connexins protect mouse pancreatic β cells against apoptosis. J Clin Invest 2011; 121:4870-9. [PMID: 22056383 PMCID: PMC3225984 DOI: 10.1172/jci40509] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 09/28/2011] [Indexed: 12/18/2022] Open
Abstract
Type 1 diabetes develops when most insulin-producing β cells of the pancreas are killed by an autoimmune attack. The in vivo conditions modulating the sensitivity and resistance of β cells to this attack remain largely obscure. Here, we show that connexin 36 (Cx36), a trans-membrane protein that forms gap junctions between β cells in the pancreatic islets, protects mouse β cells against both cytotoxic drugs and cytokines that prevail in the islet environment at the onset of type 1 diabetes. We documented that this protection was at least partially dependent on intercellular communication, which Cx36 and other types of connexin channels establish within pancreatic islets. We further found that proinflammatory cytokines decreased expression of Cx36 and that experimental reduction or augmentation of Cx36 levels increased or decreased β cell apoptosis, respectively. Thus, we conclude that Cx36 is central to β cell protection from toxic insults.
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Affiliation(s)
- Philippe Klee
- Department of Cell Physiology and Metabolism, University of Geneva, Medical School, Geneva, Switzerland.
Service of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Florent Allagnat
- Department of Cell Physiology and Metabolism, University of Geneva, Medical School, Geneva, Switzerland.
Service of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Helena Pontes
- Department of Cell Physiology and Metabolism, University of Geneva, Medical School, Geneva, Switzerland.
Service of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Manon Cederroth
- Department of Cell Physiology and Metabolism, University of Geneva, Medical School, Geneva, Switzerland.
Service of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Anne Charollais
- Department of Cell Physiology and Metabolism, University of Geneva, Medical School, Geneva, Switzerland.
Service of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Dorothée Caille
- Department of Cell Physiology and Metabolism, University of Geneva, Medical School, Geneva, Switzerland.
Service of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Aurore Britan
- Department of Cell Physiology and Metabolism, University of Geneva, Medical School, Geneva, Switzerland.
Service of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Jacques-Antoine Haefliger
- Department of Cell Physiology and Metabolism, University of Geneva, Medical School, Geneva, Switzerland.
Service of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, University of Geneva, Medical School, Geneva, Switzerland.
Service of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
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Abstract
The appearance of multicellular organisms imposed the development of several mechanisms for cell-to-cell communication, whereby different types of cells coordinate their function. Some of these mechanisms depend on the intercellular diffusion of signal molecules in the extracellular spaces, whereas others require cell-to-cell contact. Among the latter mechanisms, those provided by the proteins of the connexin family are widespread in most tissues. Connexin signaling is achieved via direct exchanges of cytosolic molecules between adjacent cells at gap junctions, for cell-to-cell coupling, and possibly also involves the formation of membrane "hemi-channels," for the extracellular release of cytosolic signals, direct interactions between connexins and other cell proteins, and coordinated influence on the expression of multiple genes. Connexin signaling appears to be an obligatory attribute of all multicellular exocrine and endocrine glands. Specifically, the experimental evidence we review here points to a direct participation of the Cx36 isoform in the function of the insulin-producing β-cells of the endocrine pancreas, and of the Cx40 isoform in the function of the renin-producing juxtaglomerular epithelioid cells of the kidney cortex.
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Affiliation(s)
- Domenico Bosco
- Department of Surgery, University of Geneva Medical School, Geneva, Switzerland
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39
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Abstract
Diabetes develops when the insulin needs of peripheral cells exceed the availability or action of the hormone. This situation results from the death of most beta-cells in type 1 diabetes, and from an inability of the beta-cell mass to adapt to increasing insulin needs in type 2 and gestational diabetes. We analyzed several lines of transgenic mice and showed that connexins (Cxs), the transmembrane proteins that form gap junctions, are implicated in the modulation of the beta-cell mass. Specifically, we found that the native Cx36 does not alter islet size or insulin content, whereas the Cx43 isoform increases both parameters, and Cx32 has a similar effect only when combined with GH. These findings open interesting perspectives for the in vitro and in vivo regulation of the beta-cell mass.
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Affiliation(s)
- Philippe Klee
- Department of Pediatrics, University Hospital of Geneva, Geneva 1211, Switzerland.
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40
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Alonso F, Boittin FX, Bény JL, Haefliger JA. Loss of connexin40 is associated with decreased endothelium-dependent relaxations and eNOS levels in the mouse aorta. Am J Physiol Heart Circ Physiol 2010; 299:H1365-73. [PMID: 20802140 DOI: 10.1152/ajpheart.00029.2010] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Upon agonist stimulation, endothelial cells trigger smooth muscle relaxation through the release of relaxing factors such as nitric oxide (NO). Endothelial cells of mouse aorta are interconnected by gap junctions made of connexin40 (Cx40) and connexin37 (Cx37), allowing the exchange of signaling molecules to coordinate their activity. Wild-type (Cx40(+/+)) and hypertensive Cx40-deficient mice (Cx40(-/-)), which also exhibit a marked decrease of Cx37 in the endothelium, were used to investigate the link between the expression of endothelial connexins (Cx40 and Cx37) and endothelial nitric oxide synthase (eNOS) expression and function in the mouse aorta. With the use of isometric tension measurements in aortic rings precontracted with U-46619, a stable thromboxane A(2) mimetic, we first demonstrate that ACh- and ATP-induced endothelium-dependent relaxations solely depend on NO release in both Cx40(+/+) and Cx40(-/-) mice, but are markedly weaker in Cx40(-/-) mice. Consistently, both basal and ACh- or ATP-induced NO production were decreased in the aorta of Cx40(-/-) mice. Altered relaxations and NO release from aorta of Cx40(-/-) mice were associated with lower expression levels of eNOS in the aortic endothelium of Cx40(-/-) mice. Using immunoprecipitation and in situ ligation assay, we further demonstrate that eNOS, Cx40, and Cx37 tightly interact with each other at intercellular junctions in the aortic endothelium of Cx40(+/+) mice, suggesting that the absence of Cx40 in association with altered Cx37 levels in endothelial cells from Cx40(-/-) mice participate to the decreased levels of eNOS. Altogether, our data suggest that the endothelial connexins may participate in the control of eNOS expression levels and function.
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Affiliation(s)
- Florian Alonso
- Service of Internal Medicine, Laboratory of Experimental Medicine 19–135S, University Hospital, CHUV, Lausanne, Switzerland
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41
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Alonso F, Krattinger N, Mazzolai L, Simon A, Waeber G, Meda P, Haefliger JA. An angiotensin II- and NF-kappaB-dependent mechanism increases connexin 43 in murine arteries targeted by renin-dependent hypertension. Cardiovasc Res 2010; 87:166-76. [PMID: 20110337 PMCID: PMC2883896 DOI: 10.1093/cvr/cvq031] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 01/20/2010] [Accepted: 01/25/2010] [Indexed: 01/17/2023] Open
Abstract
AIMS Connexins (Cxs) play a role in the contractility of the aorta wall. We investigated how connexins of the endothelial cells (ECs; Cx37, Cx40) and smooth muscle cells (SMCs; Cx43, Cx45) of the aorta change during renin-dependent and -independent hypertension. METHODS AND RESULTS We subjected both wild-type (WT) mice and mice lacking Cx40 (Cx40(-/-)), to either a two-kidney, one-clip procedure or to N-nitro-l-arginine-methyl-ester treatment, which induce renin-dependent and -independent hypertension, respectively. All hypertensive mice featured a thickened aortic wall, increased levels of Cx37 and Cx45 in SMC, and of Cx40 in EC (except in Cx40(-/-) mice). Cx43 was up-regulated, with no effect on its S368 phosphorylation, only in the SMCs of renin-dependent models of hypertension. Blockade of the renin-angiotensin system of Cx40(-/-) mice normalized blood pressure and prevented both aortic thickening and Cx alterations. Ex vivo exposure of WT aortas, carotids, and mesenteric arteries to physiologically relevant levels of angiotensin II (AngII) increased the levels of Cx43, but not of other Cx. In the aortic SMC line of A7r5 cells, AngII activated kinase-dependent pathways and induced binding of the nuclear factor-kappa B (NF-kappaB) to the Cx43 gene promoter, increasing Cx43 expression. CONCLUSION In both large and small arteries, hypertension differently regulates Cx expression in SMC and EC layers. Cx43 is selectively increased in renin-dependent hypertension via an AngII activation of the extracellular signal-regulated kinase and NF-kappaB pathways.
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MESH Headings
- Angiotensin II/metabolism
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Angiotensin-Converting Enzyme Inhibitors/pharmacology
- Animals
- Antihypertensive Agents/pharmacology
- Aorta/drug effects
- Aorta/metabolism
- Aorta/physiopathology
- Binding Sites
- Blood Pressure
- Carotid Arteries/metabolism
- Carotid Arteries/physiopathology
- Cell Line
- Connexin 43/genetics
- Connexin 43/metabolism
- Connexins/deficiency
- Connexins/genetics
- Disease Models, Animal
- Endothelial Cells/metabolism
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Genes, Reporter
- Hypertension, Renovascular/drug therapy
- Hypertension, Renovascular/etiology
- Hypertension, Renovascular/metabolism
- Hypertension, Renovascular/physiopathology
- Mesenteric Arteries/metabolism
- Mesenteric Arteries/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myocytes, Smooth Muscle/metabolism
- NF-kappa B/metabolism
- NG-Nitroarginine Methyl Ester
- Nephrectomy
- Phosphorylation
- Promoter Regions, Genetic
- Rats
- Renin/blood
- Time Factors
- Transfection
- Up-Regulation
- Gap Junction alpha-5 Protein
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Affiliation(s)
- Florian Alonso
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
| | - Nathalie Krattinger
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
| | - Lucia Mazzolai
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
| | - Alexander Simon
- Department of Physiology, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Gérard Waeber
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, University of Geneva, School of Medicine, CMU, 1211 Genève 4, Switzerland
| | - Jacques-Antoine Haefliger
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
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42
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Pellegrin M, Alonso F, Aubert JF, Bouzourene K, Braunersreuther V, Mach F, Haefliger JA, Hayoz D, Berthelot A, Nussberger J, Laurant P, Mazzolai L. Swimming Prevents Vulnerable Atherosclerotic Plaque Development in Hypertensive 2-Kidney, 1-Clip Mice by Modulating Angiotensin II Type 1 Receptor Expression Independently From Hemodynamic Changes. Hypertension 2009; 53:782-9. [DOI: 10.1161/hypertensionaha.108.128165] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Maxime Pellegrin
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Florian Alonso
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Jean-François Aubert
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Karima Bouzourene
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Vincent Braunersreuther
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - François Mach
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Jacques-Antoine Haefliger
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Daniel Hayoz
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Alain Berthelot
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Jürg Nussberger
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Pascal Laurant
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
| | - Lucia Mazzolai
- From the Service of Vascular Medicine (M.P., J.-F.A., K.B., D.H., J.N., L.M.) and Service of Internal Medicine (F.A., J.-A.H.), Lausanne University Hospital, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; EA-4267/2SBP (A.B., P.L.), Exercise Prevention Innovation and Technico-Sporting Watching Department, University of Franche-Comté, Besançon, France; Division of Cardiology (V.B., F.M.), University Hospital, Foundation for Medical Researches, Geneva, Switzerland; and the
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Krattinger N, Alonso F, Capponi A, Mazzolai L, Nicod P, Meda P, Haefliger JA. Increased expression of renal cyclooxygenase-2 and neuronal nitric oxide synthase in hypertensive Cx40-deficient mice. J Vasc Res 2008; 46:188-98. [PMID: 18812700 DOI: 10.1159/000156704] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Accepted: 04/12/2008] [Indexed: 11/19/2022] Open
Abstract
Cx40-deficient mice (Cx40-/-) are hypertensive due to increased renin secretion. We evaluated the renal expression of neuronal nitric oxide synthase (nNOS) and cyclooxygenases COX-1 and COX-2, three macula densa enzymes. The levels of nNOS were increased in kidneys of Cx40-/- mice, as well as in those of wild-type (WT) mice subjected to the two-kidney one-clip model of hypertension. In contrast, the levels of COX-2 expression were only increased in the hypoperfused kidney of Cx40-/- mice. Treatment with indomethacin lowered blood pressure and renin mRNA in Cx40-/- mice without affecting renin levels, indicating that changes in COX-2 do not cause the altered secretion of renin. Suppression of NOS activity by N(G)-nitro-L-arginine methyl ester (L-NAME) decreased renin levels in Cx40-/- animals, indicating that NO regulates renin expression in the absence of Cx40. Treatment with candesartan normalized blood pressure in Cx40-/- mice, and decreased the levels of both COX-2 and nNOS. After a treatment combining candesartan and L-NAME, the blood pressure of Cx40-/- mice was higher than that of WT mice, showing that NO may counterbalance the vasoconstrictor effects of angiotensin II in Cx40-/- mice. These data document that renal COX-2 and nNOS are differentially regulated due to the elevation of renin-dependent blood pressure in mice lacking Cx40.
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Allagnat F, Alonso F, Martin D, Abderrahmani A, Waeber G, Haefliger JA. ICER-1gamma overexpression drives palmitate-mediated connexin36 down-regulation in insulin-secreting cells. J Biol Chem 2008; 283:5226-34. [PMID: 18073214 DOI: 10.1074/jbc.m708181200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Channels formed by the gap junction protein connexin36 (Cx36) contribute to the proper control of insulin secretion. We investigated the impact of chronic hyperlipidemia on Cx36 expression in pancreatic beta-cells. Prolonged exposure to the saturated free fatty acid palmitate reduced the expression of Cx36 in several insulin-secreting cell lines and isolated mouse islets. The effect of palmitate was fully blocked upon protein kinase A (PKA) inhibition by H89 and (Rp)-cAMP, indicating that the cAMP/PKA pathway is involved in the control of Cx36 expression. Palmitate treatment led to overexpression of the inducible cAMP early repressor (ICER-1gamma), which bound to a functional cAMP-response element located in the promoter of the CX36 gene. Inhibition of ICER-1gamma overexpression prevented the Cx36 decrease, as well as the palmitate-induced beta-cell secretory dysfunction. Finally, freshly isolated islets from mice undergoing a long term high fat diet expressed reduced Cx36 levels and increased ICER-1gamma levels. Taken together, these data demonstrate that chronic exposure to palmitate inhibits the Cx36 expression through PKA-mediated ICER-1gamma overexpression. This Cx36 down-regulation may contribute to the reduced glucose sensitivity and altered insulin secretion observed during the pre-diabetic stage and in the metabolic syndrome.
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Affiliation(s)
- Florent Allagnat
- Department of Medicine, University Hospital, CHUV-1011 Lausanne, Switzerland
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Yang JY, Moulin N, van Bemmelen MX, Dubuis G, Tawadros T, Haefliger JA, Waeber G, Widmann C. Splice variant-specific stabilization of JNKs by IB1/JIP1. Cell Signal 2007; 19:2201-7. [PMID: 17669625 DOI: 10.1016/j.cellsig.2007.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Accepted: 07/02/2007] [Indexed: 11/30/2022]
Abstract
Islet-Brain 1 (IB1) (also called JNK-interacting protein 1; JIP1) is a scaffold protein that tethers components of the JNK mitogen-activated protein kinase pathway inducing a modulation of the activity and the target specificity of the JNK kinases. Dysfunctions in IB1 have been associated with diseases such as early type II diabetes. To gain more insight in the functions of IB1, its ability to modulate the expression levels of the various JNK proteins was assessed. Each of the three JNK genes gives rise to several splice variants encoding short or long proteins. The expression levels of the short JNK proteins, but not of the long variants, were systematically higher in rat tissues and in transformed cell lines expressing high IB1 levels compared to tissues and cells with no or low IB1 expression. HEK293 cells bearing a tetracycline-inducible IB1 construct showed a specific increase of the short JNK endogenous splice variants in the presence of tetracycline. The augmented expression level of the short JNK splice variants induced by IB1 resulted from an increased stability towards degradation. Modulation of the stability of specific JNK splice variants represents therefore a newly identified mechanism used by IB1 to regulate the JNK MAPK pathway.
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Affiliation(s)
- Jiang-Yan Yang
- Department of Physiology, Biology and Medicine Faculty, University of Lausanne, Bugnon 7, 1005 Lausanne, Switzerland
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Abstract
Transmigration of neutrophil polymorphonuclear leukocytes through the microvascular endothelium is a cardinal event of acute inflammation. In vitro, this process can be restricted by gap junctional intercellular communication, but whether it also occurs in vivo is unknown. Connexin 40 (Cx40) is a gap junctional protein abundantly present in the lung, notably in vascular endothelium. We hypothesized that acute lung inflammation would be aggravated in knockout mice genetically deficient in Cx40. This hypothesis was tested in two different models: 1) intranasal instillation of LPS at either supramaximal (50 microg/mouse) or inframaximal dose (0.01 microg/mouse) and 2) pulmonary inflammation as a distant consequence of an abdominal infection caused by cecal ligation and perforation. Pulmonary transmigration of neutrophils was assessed by counting these cells in bronchoalveolar lavage fluid (LPS model) or with the myeloperoxidase assay in homogenates of blood-free tissue (cecal ligation and perforation model). Pulmonary content in Cx40 and Cx43 was evaluated with immunoblots. In wild-type mice, there was a time-dependent decrease of Cx40 expression in both models. The time points for studies with the knockout mice were chosen in such a manner that inflammation was clearly present and Cx40 still largely expressed in wild-type animals. In either model, the development of lung inflammation did not differ between wild-type and Cx40-deficient mice. In conclusion, the pulmonary expression of the Cx40 protein is progressively and markedly decreased in two different murine models of acute lung inflammation, but there is no causal relationship between this process and the pulmonary transmigration of neutrophils.
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Affiliation(s)
- Stéphanie Rignault
- Division de Physiopathologie Clinique, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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Membrez M, Hummler E, Beermann F, Haefliger JA, Savioz R, Pedrazzini T, Thorens B. GLUT8 is dispensable for embryonic development but influences hippocampal neurogenesis and heart function. Mol Cell Biol 2006; 26:4268-76. [PMID: 16705176 PMCID: PMC1489108 DOI: 10.1128/mcb.00081-06] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
GLUT8 is a glucose transporter isoform expressed at high levels in testis; at intermediate levels in the brain, including the hippocampus; and at lower levels in the heart and several other tissues. GLUT8 is located in an intracellular compartment and does not appear to translocate to the cell surface, except in blastocysts, where insulin has been reported to induce its surface expression. Here, we generated mice with inactivation of the glut8 gene. We showed that expression of GLUT8 was not required for normal embryonic development and that glut8-/- mice had normal postnatal development, glucose homeostasis, and response to mild stress. Adult glut8-/- mice showed increased proliferation of hippocampal cells but no defect in memory acquisition and retention. Absence of GLUT8 from the heart did not alter heart size and morphology but led to an increase in P-wave duration, which was not associated with abnormal Nav1.5 Na+ channel or connexin expression. Thus, absence of GLUT8 expression in the mouse caused complex but mild physiological alterations.
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Affiliation(s)
- Mathieu Membrez
- Institute of Physiology, University of Lausanne, Center for Integrative Genomics, Génopode Building, CH-1015 Lausanne, Switzerland
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Haefliger JA, Krattinger N, Martin D, Pedrazzini T, Capponi A, Döring B, Plum A, Charollais A, Willecke K, Meda P. Connexin43-dependent mechanism modulates renin secretion and hypertension. J Clin Invest 2006; 116:405-13. [PMID: 16440062 PMCID: PMC1350996 DOI: 10.1172/jci23327] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2004] [Accepted: 11/29/2005] [Indexed: 02/03/2023] Open
Abstract
To investigate the function of Cx43 during hypertension, we studied the mouse line Cx43KI32 (KI32), in which the coding region of Cx32 replaces that of Cx43. Within the kidneys of homozygous KI32 mice, Cx32 was expressed in cortical and medullary tubules, as well as in some extra- and intraglomerular vessels, i.e., at sites where Cx32 and Cx43 are found in WT mice. Under such conditions, renin expression was much reduced compared with that observed in the kidneys of WT and heterozygous KI32 littermates. After exposure to a high-salt diet, all mice retained a normal blood pressure. However, whereas the levels of renin were significantly reduced in the kidneys of WT and heterozygous KI32 mice, reaching levels comparable to those observed in homozygous littermates, they were not further affected in the latter animals. Four weeks after the clipping of a renal artery (the 2-kidney, 1-clip [2K1C] model), 2K1C WT and heterozygous mice showed an increase in blood pressure and in the circulating levels of renin, whereas 2K1C homozygous littermates remained normotensive and showed unchanged plasma renin activity. Hypertensive, but not normotensive, mice also developed cardiac hypertrophy. The data indicate that replacement of Cx43 by Cx32 is associated with decreased expression and secretion of renin, thus preventing the renin-dependent hypertension that is normally induced in the 2K1C model.
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Abstract
The gap-junction protein connexin36 (Cx36) contributes to control the functions of insulin-producing cells. In this study, we investigated whether the expression of Cx36 is regulated by glucose in insulin-producing cells. Glucose caused a significant reduction of Cx36 in insulin-secreting cell lines and freshly isolated pancreatic rat islets. This decrease appeared at the mRNA and the protein levels in a dose- and time-dependent manner. 2-Deoxyglucose partially reproduced the effect of glucose, whereas glucosamine, 3-O-methyl-D-glucose and leucine were ineffective. Moreover, KCl-induced depolarization of beta-cells had no effect on Cx36 expression, indicating that glucose metabolism and ATP production are not mandatory for glucose-induced Cx36 downregulation. Forskolin mimicked the repression of Cx36 by glucose. Glucose or forskolin effects on Cx36 expression were not suppressed by the L-type Ca(2+)-channel blocker nifedipine but were fully blunted by the cAMP-dependent protein kinase (PKA) inhibitor H89. A 4 kb fragment of the human Cx36 promoter was identified and sequenced. Reporter-gene activity driven by various Cx36 promoter fragments indicated that Cx36 repression requires the presence of a highly conserved cAMP responsive element (CRE). Electrophoretic-mobility-shift assays revealed that, in the presence of a high glucose concentration, the binding activity of the repressor CRE-modulator 1 (CREM-1) is enhanced. Taken together, these data provide evidence that glucose represses the expression of Cx36 through the cAMP-PKA pathway, which activates a member of the CRE binding protein family.
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Affiliation(s)
- Florent Allagnat
- Department of Internal Medicine, Laboratory of Molecular Biology 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
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