1
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Haefliger JA, Meda P, Alonso F. Endothelial Connexins in Developmental and Pathological Angiogenesis. Cold Spring Harb Perspect Med 2022; 12:a041158. [PMID: 35074793 PMCID: PMC9159259 DOI: 10.1101/cshperspect.a041158] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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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2
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Abstract
Of the 21 members of the connexin family, 4 (Cx37, Cx40, Cx43, and Cx45) are expressed in the endothelium and/or smooth muscle of intact blood vessels to a variable and dynamically regulated degree. Full-length connexins oligomerize and form channel structures connecting the cytosol of adjacent cells (gap junctions) or the cytosol with the extracellular space (hemichannels). The different connexins vary mainly with regard to length and sequence of their cytosolic COOH-terminal tails. These COOH-terminal parts, which in the case of Cx43 are also translated as independent short isoforms, are involved in various cellular signaling cascades and regulate cell functions. This review focuses on channel-dependent and -independent effects of connexins in vascular cells. Channels play an essential role in coordinating and synchronizing endothelial and smooth muscle activity and in their interplay, in the control of vasomotor actions of blood vessels including endothelial cell reactivity to agonist stimulation, nitric oxide-dependent dilation, and endothelial-derived hyperpolarizing factor-type responses. Further channel-dependent and -independent roles of connexins in blood vessel function range from basic processes of vascular remodeling and angiogenesis to vascular permeability and interactions with leukocytes with the vessel wall. Together, these connexin functions constitute an often underestimated basis for the enormous plasticity of vascular morphology and function enabling the required dynamic adaptation of the vascular system to varying tissue demands.
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Affiliation(s)
- Ulrich Pohl
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Planegg-Martinsried, Germany; Biomedical Centre, Cardiovascular Physiology, LMU Munich, Planegg-Martinsried, Germany; German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Munich, Germany; and Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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3
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Yin J, Lv L, Zhai P, Long T, Zhou Q, Pan H, Botwe G, Wang L, Wang Q, Tan L, Kuebler WM. Connexin 40 regulates lung endothelial permeability in acute lung injury via the ROCK1-MYPT1- MLC20 pathway. Am J Physiol Lung Cell Mol Physiol 2019; 316:L35-L44. [PMID: 30234377 DOI: 10.1152/ajplung.00012.2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increased pulmonary vascular permeability is a hallmark of acute lung injury (ALI). Connexin 40 (Cx40) is a gap junctional protein abundantly present in the lung microvascular endothelium. Yet, the role of Cx40 in the regulation of lung vascular permeability and its underlying mechanisms are unclear. Here, we tested the hypothesis that Cx40 participates in regulation of lung endothelial permeability via a mechanism involving a Rho-associated protein kinase (ROCK) dependent regulation of myosin light chain (MLC). In murine models of intratracheal acid- or LPS-induced lung injury, genetic deficiency of Cx40 attenuated key features of ALI including vascular barrier failure. In human pulmonary microvascular endothelial cells (PMVECs), thrombin-induced loss of transendothelial electrical resistance was attenuated by a Cx40-inhibiting mimetic peptide (40GAP27), Cx40-specific shRNA, or ROCK inhibitor Y27632. In isolated perfused mouse lungs, platelet-activating factor-induced lung weight gain was abrogated by gap junction blocker carbenoxolone, 40GAP27, Y27632, or genetic deficiency of Cx40. Phosphorylation of MLC20 increased drastically in both LPS-treated PMVECs and HCl-treated mouse lungs. Expression of ROCK1 was increased in both LPS-treated PMVECs and HCl-treated mouse lungs, and paralleled by phosphorylation of MLC20. Coimmunoprecipitation experiments revealed protein-protein interaction between ROCK1 and Cx40. LPS-induced upregulation of ROCK1 and phosphorylation of MLC20 were blocked by knockdown of Cx40. LPS caused phosphorylation of myosin phosphatase targeting subunit 1, which could be abrogated by Y27632 or Cx40-shRNA. Our findings reveal a role of Cx40 in regulation of ROCK1 and MLC20 that contributes critically to lung vascular barrier failure in ALI.
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Affiliation(s)
- Jun Yin
- Department of Thoracic Surgery, Zhongshan Hospital of Fudan University , Shanghai , China
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Lu Lv
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Peng Zhai
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Tao Long
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Qiang Zhou
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Huiwen Pan
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Godwin Botwe
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Liming Wang
- Department of Chemotherapy, Cancer Institute, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Qun Wang
- Department of Thoracic Surgery, Zhongshan Hospital of Fudan University , Shanghai , China
| | - Lijie Tan
- Department of Thoracic Surgery, Zhongshan Hospital of Fudan University , Shanghai , China
| | - Wolfgang M Kuebler
- Department of Physiology and Center for Cardiovascular Research, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health , Berlin , Germany
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4
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Zhou HS, Li M, Sui BD, Wei L, Hou R, Chen WS, Li Q, Bi SH, Zhang JZ, Yi DH. Lipopolysaccharide impairs permeability of pulmonary microvascular endothelial cells via Connexin40. Microvasc Res 2018; 115:58-67. [PMID: 28870649 DOI: 10.1016/j.mvr.2017.08.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 07/25/2017] [Accepted: 08/30/2017] [Indexed: 12/27/2022]
Abstract
The endotoxin lipopolysaccharide (LPS)-induced pulmonary endothelial barrier disruption is a key pathogenesis of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). However, the molecular mechanisms underlying LPS-impaired permeability of pulmonary microvascular endothelial cells (PMVECs) are not fully understood. Gap junctions, particularly Connexin40 (Cx40), are necessary for the maintenance of normal vascular function. In this study, we for the first time investigated the role of Cx40 in LPS-impaired permeability of PMVECs and provided potential therapeutic approaches based on mechanistic findings of Cx40 regulation by LPS stimuli. Rat PMVECs were isolated, cultured and identified with cell morphology, specific markers, ultrastructural characteristics and functional tests. Western blot analysis demonstrated that Cx40 is the major connexin highly expressed in PMVECs. Furthermore, by inhibiting Cx40 in a time-dependent manner, LPS impaired gap junction function and induced permeability injury of PMVECs. The key role of Cx40 decline in mediating detrimental effects of LPS was further confirmed in rescue experiments through Cx40 overexpression. Mechanistically, LPS stress on PMVECs inhibited the protein kinase C (PKC) pathway, which may synergize with the inflammatory nuclear factor kappaB (NFκB) signaling activation in suppressing Cx40 expression level and phosphorylation. Moreover, through pharmacological PKC activation or NFκB inhibition, Cx40 activity in PMVECs could be restored, leading to maintained barrier function under LPS stress. Our findings uncover a previously unrecognized role of Cx40 and its regulatory mechanisms in impaired endothelial integrity under endotoxin and inflammation, shedding light on intervention approaches to improve pulmonary endothelial barrier function in ALI and ARDS.
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Affiliation(s)
- Hua-Song Zhou
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Meng Li
- State Key Laboratory of Military Stomatology, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Bing-Dong Sui
- State Key Laboratory of Military Stomatology, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China; Department of Anatomy and Cell Biology, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA 19104, USA
| | - Lei Wei
- Xi'an Satellite Control Centre Clinic, Xi'an, Shaanxi 710043, China
| | - Rui Hou
- State Key Laboratory of Military Stomatology, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Wen-Sheng Chen
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Qiang Li
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Sheng-Hui Bi
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Jin-Zhou Zhang
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
| | - Ding-Hua Yi
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
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5
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Valdebenito S, Barreto A, Eugenin EA. The role of connexin and pannexin containing channels in the innate and acquired immune response. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:154-165. [PMID: 28559189 DOI: 10.1016/j.bbamem.2017.05.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 05/17/2017] [Accepted: 05/25/2017] [Indexed: 12/20/2022]
Abstract
Connexin (Cx) and pannexin (Panx) containing channels - gap junctions (GJs) and hemichannels (HCs) - are present in virtually all cells and tissues. Currently, the role of these channels under physiological conditions is well defined. However, their role in the immune response and pathological conditions has only recently been explored. Data from several laboratories demonstrates that infectious agents, including HIV, have evolved to take advantage of GJs and HCs to improve viral/bacterial replication, enhance inflammation, and help spread toxicity into neighboring areas. In the current review, we discuss the role of Cx and Panx containing channels in immune activation and the pathogenesis of several infectious diseases. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Silvana Valdebenito
- Public Health Research Institute (PHRI), Newark, NJ, USA; Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA
| | - Andrea Barreto
- Public Health Research Institute (PHRI), Newark, NJ, USA; Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA
| | - Eliseo A Eugenin
- Public Health Research Institute (PHRI), Newark, NJ, USA; Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA.
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6
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Frimmel K, Sotníková R, Navarová J, Bernátová I, KriŽák J, Haviarová Z, Kura B, Slezák J, Okruhlicová Ľ. Omega-3 fatty acids reduce lipopolysaccharide-induced abnormalities in expression of connexin-40 in aorta of hereditary hypertriglyceridemic rats. Physiol Res 2016; 65 Suppl 1:S65-76. [PMID: 27643941 DOI: 10.33549/physiolres.933401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Omega-3 fatty acids (omega3FA) are known to reduce hypertriglyceridemia- and inflammation-induced vascular wall diseases. However, mechanisms of their effects are not completely clear. We examined, whether 10-day omega3FA diet can reduce bacterial lipopolysaccharide-induced changes in expression of gap junction protein connexin40 (Cx40) in the aorta of hereditary hypertriglyceridemic (hHTG) rats. After administration of a single dose of lipopolysaccharide (LPS, 1 mg/kg, i.p.) to adult hHTG rats, animals were fed with omega3FA diet (30 mg/kg/day) for 10 days. LPS decreased Cx40 expression that was associated with reduced acetylcholine-induced relaxation of aorta. Omega3FA administration to LPS rats had partial anti-inflammatory effects, associated with increased Cx40 expression and improved endothelium dependent relaxation of the aorta. Our results suggest that 10-day omega3FA diet could protect endothelium-dependent relaxation of the aorta of hHTG rats against LPS-induced damage through the modulation of endothelial Cx40 expression.
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Affiliation(s)
- K Frimmel
- Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic.
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7
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Willebrords J, Crespo Yanguas S, Maes M, Decrock E, Wang N, Leybaert L, Kwak BR, Green CR, Cogliati B, Vinken M. Connexins and their channels in inflammation. Crit Rev Biochem Mol Biol 2016; 51:413-439. [PMID: 27387655 PMCID: PMC5584657 DOI: 10.1080/10409238.2016.1204980] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Inflammation may be caused by a variety of factors and is a hallmark of a plethora of acute and chronic diseases. The purpose of inflammation is to eliminate the initial cell injury trigger, to clear out dead cells from damaged tissue and to initiate tissue regeneration. Despite the wealth of knowledge regarding the involvement of cellular communication in inflammation, studies on the role of connexin-based channels in this process have only begun to emerge in the last few years. In this paper, a state-of-the-art overview of the effects of inflammation on connexin signaling is provided. Vice versa, the involvement of connexins and their channels in inflammation will be discussed by relying on studies that use a variety of experimental tools, such as genetically modified animals, small interfering RNA and connexin-based channel blockers. A better understanding of the importance of connexin signaling in inflammation may open up towards clinical perspectives.
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Affiliation(s)
- Joost Willebrords
- Department of In Vitro Toxicology and
Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels,
Belgium; Joost Willebrords: + Tel: 32 2 477 45 87, Michaël Maes: Tel: +32 2
477 45 87, Sara Crespo Yanguas: Tel: +32 2 477 45 87
| | - Sara Crespo Yanguas
- Department of In Vitro Toxicology and
Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels,
Belgium; Joost Willebrords: + Tel: 32 2 477 45 87, Michaël Maes: Tel: +32 2
477 45 87, Sara Crespo Yanguas: Tel: +32 2 477 45 87
| | - Michaël Maes
- Department of In Vitro Toxicology and
Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels,
Belgium; Joost Willebrords: + Tel: 32 2 477 45 87, Michaël Maes: Tel: +32 2
477 45 87, Sara Crespo Yanguas: Tel: +32 2 477 45 87
| | - Elke Decrock
- Department of Basic Medical Sciences, Physiology Group, Ghent
University, De Pintelaan 185, 9000 Ghent, Belgium; Elke Decrock: Tel: +32 9 332 39
73, Nan Wang: Tel: +32 9 332 39 38, Luc Leybaert: Tel: +32 9 332 33 66
| | - Nan Wang
- Department of Basic Medical Sciences, Physiology Group, Ghent
University, De Pintelaan 185, 9000 Ghent, Belgium; Elke Decrock: Tel: +32 9 332 39
73, Nan Wang: Tel: +32 9 332 39 38, Luc Leybaert: Tel: +32 9 332 33 66
| | - Luc Leybaert
- Department of Basic Medical Sciences, Physiology Group, Ghent
University, De Pintelaan 185, 9000 Ghent, Belgium; Elke Decrock: Tel: +32 9 332 39
73, Nan Wang: Tel: +32 9 332 39 38, Luc Leybaert: Tel: +32 9 332 33 66
| | - Brenda R. Kwak
- Department of Pathology and Immunology and Division of Cardiology,
University of Geneva, Rue Michel-Servet 1, CH-1211 Geneva, Switzerland; Brenda R.
Kwak: Tel: +41 22 379 57 37
| | - Colin R. Green
- Department of Ophthalmology and New Zealand National Eye Centre,
University of Auckland, New Zealand; Colin R. Green: Tel: +64 9 923 61 35
| | - Bruno Cogliati
- Department of Pathology, School of Veterinary Medicine and Animal
Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87,
05508-270 São Paulo, Brazil; Bruno Cogliati: Tel: +55 11 30 91 12 00
| | - Mathieu Vinken
- Department of In Vitro Toxicology and
Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels,
Belgium; Joost Willebrords: + Tel: 32 2 477 45 87, Michaël Maes: Tel: +32 2
477 45 87, Sara Crespo Yanguas: Tel: +32 2 477 45 87
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8
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Tang M, Tian Y, Li D, Lv J, Li Q, Kuang C, Hu P, Wang Y, Wang J, Su K, Wei L. TNF-α mediated increase of HIF-1α inhibits VASP expression, which reduces alveolar-capillary barrier function during acute lung injury (ALI). PLoS One 2014; 9:e102967. [PMID: 25051011 PMCID: PMC4106849 DOI: 10.1371/journal.pone.0102967] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 06/25/2014] [Indexed: 12/21/2022] Open
Abstract
Acute lung injury (ALI) is an inflammatory disorder associated with reduced alveolar-capillary barrier function and increased pulmonary vascular permeability. Vasodilator-stimulated phosphoprotein (VASP) is widely associated with all types of modulations of cytoskeleton rearrangement-dependent cellular morphology and function, such as adhesion, shrinkage, and permeability. The present studies were conducted to investigate the effects and mechanisms by which tumor necrosis factor-alpha (TNF-α) increases the tight junction permeability in lung tissue associated with acute lung inflammation. After incubating A549 cells for 24 hours with different concentrations (0–100 ng/mL) of TNF-α, 0.1 to 8 ng/mL TNF-α exhibited no significant effect on cell viability compared with the 0 ng/mL TNF-α group (control group). However, 10 ng/mL and 100 ng/mL TNF-α dramatically inhibited the viability of A549 cells compared with the control group (*p<0.05). Monolayer cell permeability assay results indicated that A549 cells incubated with 10 ng/mL TNF-α for 24 hours displayed significantly increased cell permeability (*p<0.05). Moreover, the inhibition of VASP expression increased the cell permeability (*p<0.05). Pretreating A549 cells with cobalt chloride (to mimic a hypoxia environment) increased protein expression level of hypoxia inducible factor-1α (HIF-1α) (*p<0.05), whereas protein expression level of VASP decreased significantly (*p<0.05). In LPS-induced ALI mice, the concentrations of TNF-α in lung tissues and serum significantly increased at one hour, and the value reached a peak at four hours. Moreover, the Evans Blue absorption value of the mouse lung tissues reached a peak at four hours. The HIF-1α protein expression level in mouse lung tissues increased significantly at four hours and eight hours (**p<0.001), whereas the VASP protein expression level decreased significantly (**p<0.01). Taken together, our data demonstrate that HIF-1α acts downstream of TNF-α to inhibit VASP expression and to modulate the acute pulmonary inflammation process, and these molecules play an important role in the impairment of the alveolar-capillary barrier.
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Affiliation(s)
- Mengjie Tang
- Department of Pathology and Pathophysiology, Research Center of Food and Drug Evaluation, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, PR China
- Hunan Provincial Tumor Hospital, the Affiliated Tumor Hospital of Xiangya Medical School of Central South University, Changsha, Hunan, PR China
| | - Yihao Tian
- Department of Pathology and Pathophysiology, Research Center of Food and Drug Evaluation, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Doulin Li
- Department of Pathology and Pathophysiology, Research Center of Food and Drug Evaluation, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Jiawei Lv
- Zhongnan Hospital of Wuhan University, the Second College of Clinical Medicine of Wuhan University, Wuhan, Hubei, PR China
| | - Qun Li
- Renmin Hospital of Wuhan University, the First College of Clinical Medicine of Wuhan University, Wuhan, Hubei, PR China
| | - Changchun Kuang
- Department of Pathology and Pathophysiology, Research Center of Food and Drug Evaluation, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Pengchao Hu
- Department of Pathology and Pathophysiology, Research Center of Food and Drug Evaluation, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Ying Wang
- Department of Pathology and Pathophysiology, Research Center of Food and Drug Evaluation, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Jing Wang
- Department of Pathology and Pathophysiology, Research Center of Food and Drug Evaluation, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Ke Su
- Renmin Hospital of Wuhan University, Division of Nephrology, Wuhan, Hubei, PR China
| | - Lei Wei
- Department of Pathology and Pathophysiology, Research Center of Food and Drug Evaluation, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, PR China
- * E-mail:
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9
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LI CHONG, FU JIANHUA, LIU HONGYU, YANG HAIPING, YAO LI, YOU KAI, XUE XINDONG. Hyperoxia arrests pulmonary development in newborn rats via disruption of endothelial tight junctions and downregulation of Cx40. Mol Med Rep 2014; 10:61-7. [PMID: 24789212 PMCID: PMC4068730 DOI: 10.3892/mmr.2014.2192] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 03/17/2014] [Indexed: 11/17/2022] Open
Abstract
This study investigated changes in vascular endothelial cell tight junction structure and the expression of the gene encoding connexin 40 (Cx40) at the early pneumonedema stage of hyperoxia‑induced bronchopulmonary dysplasia (BPD) in a newborn rat model. A total of 96 newborn rats were randomly assigned to one of the following two groups, the hyperoxia group (n=48) and the control group (n=48). A hyperoxia-induced BPD model was established for the first group, while rats in the control group were maintained under normoxic conditions. Extravasation of Evans Blue (EB) was measured; the severity of lung injury was assessed; a transmission electron microscope (TEM) was used to examine the vascular endothelial cell tight junction structures, and immunohistochemical assay, western blotting and reverse transcription-polymerase chain reaction (RT-PCR) were used to evaluate the expression of Cx40 at the mRNA and protein level. Our findings showed that injuries due to BPD are progressively intensified during the time-course of exposure to hyperoxic conditions. Pulmonary vascular permeability in the hyperoxia group reached the highest level at day 5, and was significantly higher compared to the control group. TEM observations demonstrated tight junctions between endothelial cells were extremely tight. In the hyperoxia group, no marked changes in the tight junction structure were found at days 1 and 3; paracellular gaps were visible between endothelial cells at days 5 and 7. Immunohistochemical staining revealed that the Cx40 protein is mainly expressed in the vascular endothelial cells of lung tissue. Western blotting and RT-PCR assays showed a gradual decrease in Cx40 expression, depending on the exposure time to hyperoxic conditions. However, the Cx40 mRNA level reached a trough at 5 days. Overall, our study demonstrated that exposure to hyperoxia damages the tight junction structures between vascular endothelial cells and downregulates Cx40. We therefore conclude that hyperoxia may participate in the regulation of pulmonary vascular endothelial permeability.
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Affiliation(s)
- CHONG LI
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - JIANHUA FU
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - HONGYU LIU
- Department of Emergency, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - HAIPING YANG
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - LI YAO
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - KAI YOU
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - XINDONG XUE
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
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10
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Nelson TK, Sorgen PL, Burt JM. Carboxy terminus and pore-forming domain properties specific to Cx37 are necessary for Cx37-mediated suppression of insulinoma cell proliferation. Am J Physiol Cell Physiol 2013; 305:C1246-56. [PMID: 24133065 PMCID: PMC3882364 DOI: 10.1152/ajpcell.00159.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 10/15/2013] [Indexed: 11/22/2022]
Abstract
Connexin 37 (Cx37) suppresses cell proliferation when expressed in rat insulinoma (Rin) cells, an effect also manifest in vivo during vascular development and in response to tissue injury. Mutant forms of Cx37 with nonfunctional channels but normally localized, wild-type carboxy termini are not growth suppressive. Here we determined whether the carboxy-terminal (CT) domain is required for Cx37-mediated growth suppression and whether the Cx37 pore-forming domain can be replaced with the Cx43 pore-forming domain and still retain growth-suppressive properties. We show that despite forming functional gap junction channels and hemichannels, Cx37 with residues subsequent to 273 replaced with a V5-epitope tag (Cx37-273tr*V5) had no effect on the proliferation of Rin cells, did not facilitate G1-cell cycle arrest with serum deprivation, and did not prolong cell cycle time comparably to the wild-type protein. The chimera Cx43*CT37, comprising the pore-forming domain of Cx43 and CT of Cx37, also did not suppress proliferation, despite forming functional gap junctions with a permselective profile similar to wild-type Cx37. Differences in channel behavior of both Cx37-273tr*V5 and Cx43*CT37 relative to their wild-type counterparts and failure of the Cx37-CT to interact as the Cx43-CT does with the Cx43 cytoplasmic loop suggest that the Cx37-CT and pore-forming domains are both essential to growth suppression by Cx37.
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Affiliation(s)
- Tasha K Nelson
- Department of Physiology, University of Arizona, Tucson, Arizona; and
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11
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Wang L, Yin J, Nickles HT, Ranke H, Tabuchi A, Hoffmann J, Tabeling C, Barbosa-Sicard E, Chanson M, Kwak BR, Shin HS, Wu S, Isakson BE, Witzenrath M, de Wit C, Fleming I, Kuppe H, Kuebler WM. Hypoxic pulmonary vasoconstriction requires connexin 40-mediated endothelial signal conduction. J Clin Invest 2012; 122:4218-30. [PMID: 23093775 PMCID: PMC3484430 DOI: 10.1172/jci59176] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 08/30/2012] [Indexed: 12/21/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is a physiological mechanism by which pulmonary arteries constrict in hypoxic lung areas in order to redirect blood flow to areas with greater oxygen supply. Both oxygen sensing and the contractile response are thought to be intrinsic to pulmonary arterial smooth muscle cells. Here we speculated that the ideal site for oxygen sensing might instead be at the alveolocapillary level, with subsequent retrograde propagation to upstream arterioles via connexin 40 (Cx40) endothelial gap junctions. HPV was largely attenuated by Cx40-specific and nonspecific gap junction uncouplers in the lungs of wild-type mice and in lungs from mice lacking Cx40 (Cx40-/-). In vivo, hypoxemia was more severe in Cx40-/- mice than in wild-type mice. Real-time fluorescence imaging revealed that hypoxia caused endothelial membrane depolarization in alveolar capillaries that propagated to upstream arterioles in wild-type, but not Cx40-/-, mice. Transformation of endothelial depolarization into vasoconstriction involved endothelial voltage-dependent α1G subtype Ca2+ channels, cytosolic phospholipase A2, and epoxyeicosatrienoic acids. Based on these data, we propose that HPV originates at the alveolocapillary level, from which the hypoxic signal is propagated as endothelial membrane depolarization to upstream arterioles in a Cx40-dependent manner.
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MESH Headings
- Animals
- Calcium Channels/metabolism
- Connexins/genetics
- Connexins/metabolism
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Endothelium, Vascular/physiopathology
- Human Umbilical Vein Endothelial Cells
- Humans
- Hypoxia/genetics
- Hypoxia/metabolism
- Hypoxia/pathology
- Hypoxia/physiopathology
- Lung/blood supply
- Lung/metabolism
- Lung/pathology
- Lung/physiopathology
- Mice
- Mice, Knockout
- Muscle, Smooth/metabolism
- Muscle, Smooth/pathology
- Muscle, Smooth/physiopathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Phospholipases A2, Cytosolic/metabolism
- Pulmonary Artery/metabolism
- Pulmonary Artery/pathology
- Pulmonary Artery/physiopathology
- Signal Transduction
- Vasoconstriction
- Gap Junction alpha-5 Protein
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Affiliation(s)
- Liming Wang
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jun Yin
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Hannah T. Nickles
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Hannes Ranke
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Arata Tabuchi
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Julia Hoffmann
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Christoph Tabeling
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Eduardo Barbosa-Sicard
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Marc Chanson
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Brenda R. Kwak
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Hee-Sup Shin
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Songwei Wu
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Brant E. Isakson
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Martin Witzenrath
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Cor de Wit
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Ingrid Fleming
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Hermann Kuppe
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Wolfgang M. Kuebler
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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Lupu M, Khalil M, Iordache F, Andrei E, Pfannkuche K, Spitkovsky D, Baumgartner S, Rubach M, Abdelrazik H, Buzila C, Brockmeier K, Simionescu M, Hescheler J, Maniu H. Direct contact of umbilical cord blood endothelial progenitors with living cardiac tissue is a requirement for vascular tube-like structures formation. J Cell Mol Med 2012; 15:1914-26. [PMID: 21029374 PMCID: PMC3918047 DOI: 10.1111/j.1582-4934.2010.01197.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The umbilical cord blood derived endothelial progenitor cells (EPCs) contribute to vascular regeneration in experimental models of ischaemia. However, their ability to participate in cardiovascular tissue restoration has not been elucidated yet. We employed a novel coculture system to investigate whether human EPCs have the capacity to integrate into living and ischaemic cardiac tissue, and participate to neovascularization. EPCs were cocultured with either living or ischaemic murine embryonic ventricular slices, in the presence or absence of a pro-angiogenic growth factor cocktail consisting of VEGF, IGF-1, EGF and bFGF. Tracking of EPCs within the cocultures was performed by cell transfection with green fluorescent protein or by immunostaining performed with anti-human vWF, CD31, nuclei and mitochondria antibodies. EPCs generated vascular tube-like structures in direct contact with the living ventricular slices. Furthermore, the pro-angiogenic growth factor cocktail reduced significantly tubes formation. Coculture of EPCs with the living ventricular slices in a transwell system did not lead to vascular tube-like structures formation, demonstrating that the direct contact is necessary and that the soluble factors secreted by the living slices were not sufficient for their induction. No vascular tubes were formed when EPCs were cocultured with ischaemic ventricular slices, even in the presence of the pro-angiogenic cocktail. In conclusion, EPCs form vascular tube-like structures in contact with living cardiac tissue and the direct cell-to-cell interaction is a prerequisite for their induction. Understanding the cardiac niche and micro-environmental interactions that regulate EPCs integration and neovascularization are essential for applying these cells to cardiovascular regeneration.
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Affiliation(s)
- Marilena Lupu
- Institute of Cellular Biology and Pathology 'Nicolae Simionescu', Bucharest, Romania Institute for Neurophysiology, University of Cologne, Cologne, Germany
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13
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Li K, Yao J, Shi L, Sawada N, Chi Y, Yan Q, Matsue H, Kitamura M, Takeda M. Reciprocal regulation between proinflammatory cytokine-induced inducible NO synthase (iNOS) and connexin43 in bladder smooth muscle cells. J Biol Chem 2011; 286:41552-41562. [PMID: 21965676 DOI: 10.1074/jbc.m111.274449] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gap junctions (GJs) play an important role in the control of bladder contractile response and in the regulation of various immune inflammatory processes. Here, we investigated the possible interaction between inflammation and GJs in bladder smooth muscle cells (BSMCs). Stimulation of BSMCs with IL1β and TNFα increased connexin43 (Cx43) expression and function, which was associated with increased phosphorylation of vasodilator-stimulated phosphoprotein. Inhibition of PKA with H89 or down-regulation of CREB with specific siRNAs largely abolished the Cx43-elevating effect. Further analysis revealed that IL1β/TNFα induced NFκB-dependent inducible NO synthase (iNOS) expression. Inhibition of iNOS with G-nitro-l-arginine methyl ester abrogated and an exogenous NO donor mimicked the effect of the cytokines on Cx43. Intraperitoneal injection of LPS into mice also induced bladder Cx43 expression, which was largely blocked by an iNOS inhibitor. Finally, the elevated Cx43 was found to negatively regulate iNOS expression. Dysfunction of GJs with various blockers or down-regulation of Cx43 with siRNA significantly potentiated the expression of iNOS. Fibroblasts from Cx43 knock-out (Cx43(-/-)) mice also displayed a significantly higher response to the cytokine-induced iNOS expression than cells from Cx43 wild-type (Cx43(+/+)) littermates. Collectively, our study revealed a previously unrecognized reciprocal regulation loop between cytokine-induced NO and GJs. Our findings may provide an important molecular mechanism for the symptoms of bladder infection. In addition, it may further our understanding of the roles of GJs in inflammatory diseases.
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Affiliation(s)
- Kai Li
- Department of Molecular Signaling, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan; Department of Urology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan; Department of Oncology, China Medical University, Shenyang 110001, China
| | - Jian Yao
- Department of Molecular Signaling, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan.
| | - Liye Shi
- Department of Cardiology, First Affiliated Hospital, China Medical University, Shenyang 110001, China
| | - Norifumi Sawada
- Department of Urology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
| | - Yuan Chi
- Department of Molecular Signaling, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
| | - Qiaojing Yan
- Department of Molecular Signaling, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
| | - Hiroyuki Matsue
- Department of Dermatology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Masanori Kitamura
- Department of Molecular Signaling, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
| | - Masayuki Takeda
- Department of Urology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
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14
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Ceelen L, Haesebrouck F, Vanhaecke T, Rogiers V, Vinken M. Modulation of connexin signaling by bacterial pathogens and their toxins. Cell Mol Life Sci 2011; 68:3047-64. [PMID: 21656255 PMCID: PMC11115019 DOI: 10.1007/s00018-011-0737-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 05/12/2011] [Accepted: 05/17/2011] [Indexed: 02/07/2023]
Abstract
Inherent to their pivotal tasks in the maintenance of cellular homeostasis, gap junctions, connexin hemichannels, and pannexin hemichannels are frequently involved in the dysregulation of this critical balance. The present paper specifically focuses on their roles in bacterial infection and disease. In particular, the reported biological outcome of clinically important bacteria including Escherichia coli, Shigella flexneri, Yersinia enterocolitica, Helicobacter pylori, Bordetella pertussis, Aggregatibacter actinomycetemcomitans, Pseudomonas aeruginosa, Citrobacter rodentium, Clostridium species, Streptococcus pneumoniae, and Staphylococcus aureus and their toxic products on connexin- and pannexin-related signaling in host cells is reviewed. Particular attention is paid to the underlying molecular mechanisms of these effects as well as to the actual biological relevance of these findings.
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Affiliation(s)
- Liesbeth Ceelen
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium.
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15
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Okamoto T, Akiyama M, Takeda M, Akita N, Yoshida K, Hayashi T, Suzuki K. Connexin32 protects against vascular inflammation by modulating inflammatory cytokine expression by endothelial cells. Exp Cell Res 2011; 317:348-55. [PMID: 21036166 DOI: 10.1016/j.yexcr.2010.10.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 10/05/2010] [Accepted: 10/24/2010] [Indexed: 11/21/2022]
Abstract
Gap junctions (GJs) play an important role in vascular function, stability, and homeostasis in endothelial cells (ECs), and GJs are comprised of members of the connexin (Cx) family. GJs of vascular ECs are assembled from Cx37, Cx40, and Cx43, and we showed that ECs also express Cx32. In this study, we investigated a potential role for Cx32 during vascular inflammation. Expression of Cx32 mRNA and protein by human umbilical venous ECs (HUVECs) decreased following treatment with tumor necrosis factor (TNF)-α, but lipopolysaccharide (LPS) and interleukin (IL)-1β did not affect Cx32 expression. Intracellular transfer of an inhibitory anti-Cx32 monoclonal antibody significantly enhanced TNF-α-induced monocyte chemotactic protein (MCP)-1 and IL-6 expression, but overexpression of Cx32 abrogated TNF-α-induced MCP-1 and IL-6 expression. LPS treatment of Cx32 knock-out mice significantly increased the serum concentrations of TNF-α, interferon-γ, IL-6 and MCP-1, compared to wild-type littermate mice. These data suggest that Cx32 protects ECs from inflammation by regulating cytokine expression and plays an important role in the maintenance of vascular function.
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Affiliation(s)
- Takayuki Okamoto
- Department of Molecular Pathobiology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu-city, Mie 514-8507, Japan
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16
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Tyml K. Role of connexins in microvascular dysfunction during inflammation. Can J Physiol Pharmacol 2011; 89:1-12. [DOI: 10.1139/y10-099] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In arterioles, a locally initiated diameter change can propagate rapidly along the vessel length (arteriolar conducted response), thus contributing to arteriolar hemodynamic resistance. The response is underpinned by electrical coupling along the arteriolar endothelial layer. Connexins (Cx; constituents of gap junctions) are required for this coupling. This review addresses the effect of acute systemic inflammation (sepsis) on arteriolar conduction and interendothelial electrical coupling. Lipopolysaccharide (LPS; an initiating factor in sepsis) and polymicrobial sepsis (24 h model) attenuate conducted vasoconstriction in mice. In cultured microvascular endothelial cells harvested from rat and mouse skeletal muscle, LPS reduces both conducted hyperpolarization–depolarization along capillary-like structures and electrical coupling along confluent cell monolayers. LPS also tyrosine-phosphorylates Cx43 and serine-dephosphorylates Cx40. Since LPS-reduced coupling is Cx40- but not Cx43-dependent, only Cx40 dephosphorylation may be consequential. Nitric oxide (NO) overproduction is critical in advanced sepsis, since the removal of this overproduction prevents the attenuated conduction. Consistently, (i) exogenous NO in cultured cells reduces coupling in a Cx37-dependent manner, and (ii) the septic microvasculature in vivo shows no Cx40 phenotype. A complex role emerges for endothelial connexins in sepsis. Initially, LPS may reduce interendothelial coupling and arteriolar conduction by targeting Cx40, whereas NO overproduction in advanced sepsis reduces coupling and conduction by targeting Cx37 instead.
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Affiliation(s)
- Karel Tyml
- Department of Medical Biophysics, and Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5C1, Canada
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17
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Peptidoglycan derived from Staphylococcus epidermidis induces Connexin43 hemichannel activity with consequences on the innate immune response in endothelial cells. Biochem J 2010; 432:133-43. [PMID: 20815816 DOI: 10.1042/bj20091753] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Gram-positive bacterial cell wall components including PGN (peptidoglycan) elicit a potent pro-inflammatory response in diverse cell types, including endothelial cells, by activating TLR2 (Toll-like receptor 2) signalling. The functional integrity of the endothelium is under the influence of a network of gap junction intercellular communication channels composed of Cxs (connexins) that also form hemichannels, signalling conduits that are implicated in ATP release and purinergic signalling. PGN modulates Cx expression in a variety of cell types, yet effects in endothelial cells remain unresolved. Using the endothelial cell line b.End5, a 6 h challenge with PGN induced IL-6 (interleukin 6), TLR2 and Cx43 mRNA expression that was associated with enhanced Cx43 protein expression and gap junction coupling. Cx43 hemichannel activity, measured by ATP release from the cells, was induced following 15 min of exposure to PGN. Inhibition of hemichannel activity with carbenoxolone or apyrase prevented induction of IL-6 and TLR2 mRNA expression by PGN, but had no effect on Cx43 mRNA expression levels. In contrast, knockdown of TLR2 expression had no effect on PGN-induced hemichannel activity, but reduced the level of TLR2 and Cx43 mRNA expression following 6 h of PGN challenge. PGN also acutely induced hemichannel activity in HeLa cells transfected to express Cx43, but had no effect in Cx43-deficient HeLa OHIO cells. All ATP responses were blocked with Cx-specific channel blockers. We conclude that acute Cx43 hemichannel signalling plays a role in the initiation of early innate immune responses in the endothelium.
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18
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Hoyano M, Ito M, Kimura S, Tanaka K, Okamura K, Komura S, Mitsuma W, Hirono S, Chinushi M, Kodama M, Aizawa Y. Inducibility of atrial fibrillation depends not on inflammation but on atrial structural remodeling in rat experimental autoimmune myocarditis. Cardiovasc Pathol 2010; 19:e149-57. [PMID: 19747850 DOI: 10.1016/j.carpath.2009.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 07/01/2009] [Accepted: 07/08/2009] [Indexed: 10/20/2022] Open
Abstract
INTRODUCTION There is increasing evidence to support a link between inflammation and atrial fibrillation (AF). However, the role of inflammation on new-onset AF is still to be elucidated. METHODS Rats underwent induction of experimental autoimmune myocarditis (EAM). Atrial structural change was evaluated by echocardiography and histological analysis. Electrophysiological data and the in vivo atrial response to burst atrial pacing were evaluated in the acute (2 weeks after EAM induction) and chronic phases (8 weeks after induction). In addition, atrial pacing after 2, 4, and 6 h after lipopolysaccharide (LPS) infusion, when the expression of gap junctions was modified, were challenged with young healthy rats. RESULTS AF was induced in 11 of 15 chronic phase EAM rats but not in either acute phase EAM rats or LPS infusion rats (P<.01). Echocardiography showed dilatation of both atrium and ventricle and a decrease in the ejection fraction in the chronic phase. Histology revealed severe inflammatory lesions only in the acute phase. Interstitial atrial fibrosis as well as the area of atrial myocyte increased in the chronic phase but not in the acute phase. CONCLUSIONS AF could be induced in the chronic phase of myocarditis rats, but not in the acute phase of myocarditis rats or in rats with LPS infusion. Acute inflammation per se did not increase the occurrence of AF induction. Atrial structural remodeling caused by inflammation and hemodynamic effects is necessary to induce AF.
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Affiliation(s)
- Makoto Hoyano
- Division of Cardiology, Niigata University School of Medical and Dental Sciences, 1-757 Asahimachi, Niigata City, Niigata 951-8510, Japan
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19
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Li Q, Zhang J, Wang W, Liu J, Zhu H, Chen W, Chen T, Yu S, Wang H, Sun G, Yi D. Connexin40 modulates pulmonary permeability through gap junction channel in acute lung injury after thoracic gunshot wounds. THE JOURNAL OF TRAUMA 2010; 68:802-9. [PMID: 20386276 DOI: 10.1097/ta.0b013e3181bb80ea] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The permeability of pulmonary microvessel endothelial cells increases markedly after acute lung injury via paracellular gap. Connexin40 is a primary component of pulmonary microvessel endothelial cells gap junction channel and mediates intercellular communication. However, the relationship between connexin40 and the permeability of pulmonary microvessel endothelial cells is still unknown. Therefore, we determined whether connexin40 affected rabbits' pulmonary microvessel endothelial cells permeability after acute lung injury induced by gunshot trauma. METHODS We used an acute lung injury model in New Zealand rabbits following gunshot chest trauma and correlated connexin40 immunohistochemistry in gunshot lung tissue with Evans blue leak rate. Cultured pulmonary microvessel endothelial cells were divided into three groups, control (G control), injured serum (G serum), and blocker agent (G blocker). Gap junction channel function was assessed by scrape-loading and dye transfer techniques. Pulmonary microvessel endothelial cells permeability was measured by Evans blue-labeled albumin transfer. RESULTS Connexin40 expression decreased time dependently, whereas Evans blue leak rate increased. Connexin40 expression and Evans blue leak rate exhibited a strong inverse correlation (gamma = -0.934, p < 0.05). Injured serum decreased gap junction channel function, and the gap junction channel blocker aggravated this effect. Similarly, pulmonary microvessel endothelial cells permeability increased significantly in G serum and G blocker. CONCLUSIONS Connexin 40 expression in pulmonary microvasculature endothelial cells is downregulated after acute lung injury induced by gunshot trauma. This is associated with impaired gap junction channel function and increased pulmonary microvessel endothelial cells permeability.
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Affiliation(s)
- Qiang Li
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
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20
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Burnier L, Fontana P, Angelillo-Scherrer A, Kwak BR. Intercellular Communication in Atherosclerosis. Physiology (Bethesda) 2009; 24:36-44. [DOI: 10.1152/physiol.00036.2008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cell-to-cell communication is a process necessary for physiological tissue homeostasis and appears often altered during disease. Gap junction channels, formed by connexins, allow the direct intercellular communication between adjacent cells. After a brief review of the pathophysiology of atherosclerosis, we will discuss the role of connexins throughout the different stages of the disease.
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Affiliation(s)
- Laurent Burnier
- Department of Internal Medicine, Division of Cardiology,
- Department of Internal Medicine, Division of Angiology and Hemostasis, Geneva University Hospitals and University of Geneva, Geneva, Switzerland; and
- Service and Central Laboratory of Hematology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Pierre Fontana
- Department of Internal Medicine, Division of Angiology and Hemostasis, Geneva University Hospitals and University of Geneva, Geneva, Switzerland; and
| | - Anne Angelillo-Scherrer
- Service and Central Laboratory of Hematology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Brenda R. Kwak
- Department of Internal Medicine, Division of Cardiology,
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21
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Johnstone S, Isakson B, Locke D. Biological and biophysical properties of vascular connexin channels. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2009; 278:69-118. [PMID: 19815177 PMCID: PMC2878191 DOI: 10.1016/s1937-6448(09)78002-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Intercellular channels formed by connexin proteins play a pivotal role in the direct movement of ions and larger cytoplasmic solutes between vascular endothelial cells, between vascular smooth muscle cells, and between endothelial and smooth muscle cells. Multiple genetic and epigenetic factors modulate connexin expression levels and/or channel function, including cell-type-independent and cell-type-specific transcription factors, posttranslational modifications, and localized membrane targeting. Additionally, differences in protein-protein interactions, including those between connexins, significantly contribute to both vascular homeostasis and disease progression. The biophysical properties of the connexin channels identified in the vasculature, those formed by Cx37, Cx40, Cx43 and/or Cx45 proteins, are discussed in this chapter in the physiological and pathophysiological context of vessel function.
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Affiliation(s)
- Scott Johnstone
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 29908
| | - Brant Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 29908
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA 29908
| | - Darren Locke
- Department of Pharmacology and Physiology, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103
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22
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23
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Bolon ML, Peng T, Kidder GM, Tyml K. Lipopolysaccharide plus hypoxia and reoxygenation synergistically reduce electrical coupling between microvascular endothelial cells by dephosphorylating connexin40. J Cell Physiol 2008; 217:350-9. [PMID: 18521823 DOI: 10.1002/jcp.21505] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We showed that lipopolysaccharide (LPS) or hypoxia and reoxygenation (H/R) decreases electrical coupling between microvascular endothelial cells by targeting the gap junction protein connexin40 (Cx40), tyrosine kinase-, ERK1/2-, and PKA-dependently. Since LPS can compromise microvascular blood flow, resulting in micro-regional H/R, the concurrent LPS + H/R could reduce coupling to a much greater extent than LPS or H/R alone. We examined this possibility in a model of cultured microvascular endothelial cells (mouse skeletal muscle origin) in terms of electrical coupling and the phosphorylation status of Cx40. To assess coupling, we measured the spread of electrical current injected into the cell monolayer and computed the intercellular resistance as an inversed measure of coupling. In wild type cells, but not in Cx40 null cells, concurrent LPS + H/R synergistically increased resistance by approximately 270%, well above the level observed for LPS or H/R alone. Cx37 and Cx43 protein expression did not differ between Cx40 null and wild type cells. LPS + H/R increased resistance PKA- and PKC-dependently. By immunoprecipitating Cx40, we found that LPS + H/R reduced serine phosphorylation to a much greater degree than that observed for LPS or H/R alone. Further, PKA-specific, but not PKC-specific serine phosphorylation of Cx40 was also significantly reduced following LPS + H/R. This reduction was prevented by tyrosine kinase and MEK1/2 inhibition, by PKA activation, and mimicked in control cells by PKA inhibition. We conclude that LPS + H/R initiates tyrosine kinase- and ERK1/2-sensitive signaling that synergistically reduces inter-endothelial electrical coupling by dephosphorylating PKA-specific serine residues of Cx40.
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Affiliation(s)
- Michael L Bolon
- Critical Illness Research, Lawson Health Research Institute, London, Ontario, Canada
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24
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Burt JM, Nelson TK, Simon AM, Fang JS. Connexin 37 profoundly slows cell cycle progression in rat insulinoma cells. Am J Physiol Cell Physiol 2008; 295:C1103-12. [PMID: 18753315 PMCID: PMC2584977 DOI: 10.1152/ajpcell.299.2008] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2008] [Accepted: 08/23/2008] [Indexed: 12/19/2022]
Abstract
In addition to providing a pathway for intercellular communication, the gap junction-forming proteins, connexins, can serve a growth-suppressive function that is both connexin and cell-type specific. To assess its potential growth-suppressive function, we stably introduced connexin 37 (Cx37) into connexin-deficient, tumorigenic rat insulinoma (Rin) cells under the control of an inducible promoter. Proliferation of these iRin37 cells, when induced to express Cx37, was profoundly slowed: cell cycle time increased from 2 to 9 days. Proliferation and cell cycle time of Rin cells expressing Cx40 or Cx43 did not differ from Cx-deficient Rin cells. Cx37 suppressed Rin cell proliferation irrespective of cell density at the time of induced expression and without causing apoptosis. All phases of the cell cycle were prolonged by Cx37 expression, and progression through the G(1)/S checkpoint was delayed, resulting in accumulation of cells at this point. Serum deprivation augmented the effect of Cx37 to accumulate cells in late G(1). Cx43 expression also affected cell cycle progression of Rin cells, but its effects were opposite to Cx37, with decreases in G(1) and increases in S-phase cells. These effects of Cx43 were also augmented by serum deprivation. Cx-deficient Rin cells were unaffected by serum deprivation. Our results indicate that Cx37 expression suppresses cell proliferation by significantly increasing cell cycle time by extending all phases of the cell cycle and accumulating cells at the G(1)/S checkpoint.
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Affiliation(s)
- Janis M Burt
- Dept. of Physiology, P. O. Box 245051, Univ. of Arizona, Tucson, AZ 85724, USA.
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25
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Abstract
Connexins form intercellular channels that span two plasma membranes and directly couple the cytoplasm of adjacent cells. This morphological contact enables the exchange of ions, second messengers, and metabolites, which act to regulate several biological functions. This review focuses on the significance of connexins in the renal circulation. Cells of the renal vasculature are coupled and express connexins in a vessel and cell-specific pattern. This finding indicates that renal connexins likely play an important role in renal autoregulatory mechanisms (Bayliss effect, tubuloglomerular feedback) and in the control of vasomotor responses. The described coupling of endothelial and vascular smooth muscle cells in the afferent arterioles may also contribute to the communication of neighboring nephrons, called 'nephron coupling.' Furthermore, deletion of the Cx40 and Cx43 genes results in an altered functional behavior of the renin-producing cells, suggesting involvement of these connexin isoforms in the regulation of renin secretion and synthesis. In addition, this review discusses the role of renal connexin expression in the pathogenesis of hypertension or diabetes.
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Affiliation(s)
- C Wagner
- Physiologisches Institut der Universität Regensburg, Regensburg, Germany.
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26
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Rignault S, Haefliger JA, Waeber B, Liaudet L, Feihl F. Acute inflammation decreases the expression of connexin 40 in mouse lung. Shock 2007; 28:78-85. [PMID: 17483738 DOI: 10.1097/shk.0b013e3180310bd1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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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27
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Bolon ML, Kidder GM, Simon AM, Tyml K. Lipopolysaccharide reduces electrical coupling in microvascular endothelial cells by targeting connexin40 in a tyrosine-, ERK1/2-, PKA-, and PKC-dependent manner. J Cell Physiol 2007; 211:159-66. [PMID: 17149706 DOI: 10.1002/jcp.20928] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Electrical coupling along the endothelium is central in the arteriolar conducted response and in control of vascular resistance. It has been shown that exposure of endothelium to lipopolysaccharide (LPS, an initiating factor in sepsis) reduces intercellular communication in vitro and in vivo. The molecular basis for this reduction is not known. We examined the effect of LPS on electrical coupling in monolayers of cultured mouse microvascular endothelial cells (MMEC) derived from the mouse hindlimb skeletal muscle. To assess coupling, we measured the spread of electrical current injected into the monolayer and computed the monolayer intercellular resistance (inverse measure of coupling). LPS (10 microg/ml, 1 h) reduced coupling (i.e., increased resistance) in MMEC isolated from wild-type, connexin37 (Cx37) null and Cx43(G60S) (nonfunctional mutant) mice, but not in MMEC derived from Cx40 null mice. LPS also activated JNK1/2, p38 and ERK1/2 MAP kinases. Pretreatment of WT monolayers with ERK1/2 inhibitor U0126 (20 microM, 1 h) prevented the LPS-induced decrease in coupling, while inhibition of JNK1/2 with SP600125 (20 microM, 1 h) and p38 with a p38 inhibitor (10 nM, 1 h) had no effect. Furthermore, inhibition of tyrosine kinases with PP-2 (10 nM, 1 h), activation of PKA by 8-bromo-cAMP (1 mM, 5 min), and activation of PKC by bryostatin-2 (10 nM, 1 h) also prevented the reduction in coupling. We propose that LPS reduces inter-endothelial electrical coupling via tyrosine-, ERK1/2-, PKA-, and PKC-dependent signaling that targets Cx40. We suggest that this mechanism contributes to compromised arteriolar function following LPS exposure.
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Affiliation(s)
- Michael L Bolon
- The Centre for Critical Illness Research and Children's Health Research Institute, Lawson Health Research Institute, London, Canada
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28
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Shoja MM, Tubbs RS, Ansarin K. The role of myoendothelial gap junctions in the formation of arterial aneurysms: the hypothesis of "connexin 43:40 stoichiometry". Med Hypotheses 2007; 69:575-9. [PMID: 17374558 DOI: 10.1016/j.mehy.2007.01.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Accepted: 01/17/2007] [Indexed: 10/24/2022]
Abstract
Heterocellular myoendothelial gap junctions (MEGJs) are essential in coordinating and regulating vasomotion. Little is known about their potential role in disease states. We discuss how alteration in the Cx 43:40 expression ratio at the level of MEGJs may begin a chain of reactions in the arterial wall resulting in an aneurysm formation. In this model, we assumed that aneurysm is a chronic arterial disease associated with medial degeneration and intimal hyperplasia. It also was assumed that MEGJs are composed of Cx43 and Cx40 in different stoichiometry and that the characteristic of a given junction is in the favor of its most abundantly expressed constituent. The hypothesis of Cx 43:40 stoichiometry indicates that impaired MEGJs may play a role in the pathogenesis of arterial aneurysms. Cx43 upregulation and Cx40 downregulation (increased Cx 43:40 stoichiometry) may induce a cascade of inflammatory, electrical, metabolic and proliferative derangements in the arterial wall, which finally lead to the matrix degradation, intimal hyperplasia, endothelial-medial dissociation and loss of endothelium-dependent hyperpolarizing currents, irregular vasomotion, impaired growth factor activation, and arterial sympathetic deprivation. The final consequence of these alterations is aneurysm formation.
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Affiliation(s)
- Mohammadali M Shoja
- Tuberculosis and Lung Diseases Research Center, Tabriz Medical University, Tabriz, Iran.
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29
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McGown CC, Brookes ZLS. Beneficial effects of statins on the microcirculation during sepsis: the role of nitric oxide. Br J Anaesth 2007; 98:163-75. [PMID: 17251210 DOI: 10.1093/bja/ael358] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This review describes the laboratory evidence and microvascular mechanisms responsible for the beneficial effects of statins in sepsis. During sepsis, changes occur within the microcirculation including alterations in arteriolar tone influencing blood pressure, adaptations to endothelial cell integrity causing leakage of proteins and macromolecules, and adhesion and migration of leucocytes through the vascular endothelium. Statins are widely used as cholesterol-lowering agents, but appear to have anti-inflammatory actions during sepsis. We have discussed the effects of statins on specific pathological processed within the microcirculation and focused on the role of nitric oxide (NO). The main mechanism by which statins appear to be an effective treatment for sepsis is increased expression of endothelial nitric oxide synthase (eNOS), in conjunction with down-regulation of inducible nitric oxide synthase. Combined, this results in an increase in physiological concentrations of NO, thus restoring endothelial function. Laboratory studies have therefore suggested that enhancement of eNOS activity during sepsis may lead to restoration of microvascular tone, maintenance of microvascular integrity, and inhibition of cell adhesion molecules. However, other mechanisms independent of lipid-lowering effects, including antioxidant activity and alterations in the development of vascular atherosclerosis, may also contribute to the beneficial effects of statins. We have also addressed the influence on the effects of statins of lipid solubility and pre- and pro-phylactic administration.
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Affiliation(s)
- C C McGown
- Academic Unit of Anaesthesia and Microcirculation Research Group, University of Sheffield, Royal Hallamshire Hospital, Sheffield S10 2JF, UK.
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30
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Sawaya SE, Rajawat YS, Rami TG, Szalai G, Price RL, Sivasubramanian N, Mann DL, Khoury DS. Downregulation of connexin40 and increased prevalence of atrial arrhythmias in transgenic mice with cardiac-restricted overexpression of tumor necrosis factor. Am J Physiol Heart Circ Physiol 2007; 292:H1561-7. [PMID: 17122196 DOI: 10.1152/ajpheart.00285.2006] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Atrial arrhythmias, primarily atrial fibrillation, have been independently associated with structural remodeling and with inflammation. We hypothesized that sustained inflammatory signaling by tumor necrosis factor (TNF) would lead to alterations both in underlying atrial myocardial structure and in atrial electrical conduction. We performed ECG recording, intracardiac electrophysiology studies, epicardial mapping, and connexin immunohistochemical analyses on transgenic mice with targeted overexpression of TNF in the cardiac compartment (MHCsTNF) and on wild-type (WT) control mice (age 8-16 wk). Atrial and ventricular conduction abnormalities were always evident on ECG in MHCsTNF mice, including a shortened atrioventricular interval with a wide QRS duration secondary to junctional rhythm. Supraventricular arrhythmias were observed in five of eight MHCsTNF mice, whereas none of the mice demonstrated ventricular arrhythmias. No arrhythmias were observed in WT mice. Left ventricular conduction velocity during apical pacing was similar between the two mouse groups. Connexin40 was significantly downregulated in MHCsTNF mice. In contrast, connexin43 density was not significantly altered in MHCsTNF mice, but rather dispersed away from the intercalated disks. In conclusion, sustained inflammatory signaling contributed to atrial structural remodeling and downregulation of connexin40 that was associated with an increased prevalence of atrial arrhythmias.
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Affiliation(s)
- Sam E Sawaya
- Section of Cardiology, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
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31
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Rodenwaldt B, Pohl U, de Wit C. Endogenous and exogenous NO attenuates conduction of vasoconstrictions along arterioles in the microcirculation. Am J Physiol Heart Circ Physiol 2007; 292:H2341-8. [PMID: 17220177 DOI: 10.1152/ajpheart.01061.2006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vascular coordination in the microcirculation depends on gap junctional intercellular communication (GJIC), which is reflected by the conduction of locally initiated vasomotor responses. However, little is known about the regulation of GJIC in vivo. We hypothesized that endothelial NO regulates GJIC and therefore studied whether conduction of constrictions and dilations along the vessel wall is modulated by modifying the level of microcirculatory NO. Arterioles were focally stimulated using high K(+) or acetylcholine in the cremaster muscle in situ, and diameter changes were assessed at the local and remote upstream sites by intravital microscopy. Local stimulation with K(+) initiated a constriction that conducted along the arteriole with diminishing amplitude (length constant lambda: 371 +/- 42 mum). After N(omega)-nitro-l-arginine (l-NNA), lambda increased to 507 +/- 30 mum, indicating that GJIC is attenuated by endogenous NO. Exogenous NO, but not adenosine, reduced lambda after l-NNA in a reversible, concentration-dependent, and mainly cGMP-dependent manner as assessed by inhibition of soluble guanylate cyclase. In endothelial NO synthase-deficient mice, lambda was 530 +/- 80 mum and thus similar to that in wild-type mice after l-NNA. Exogenous NO likewise reduced lambda in these mice. The effects of NO were comparable to those of wild-type animals in Cx40-deficient mice, which excludes Cx40 as a specific target of NO. In contrast to constrictions, the amplitude of conducted dilations on acetylcholine did not diminish up to 1,300 mum and were not altered by l-NNA or exogenous NO. We conclude that endogenously released NO attenuates the conduction of vasoconstrictions most likely due to a modulation of gap junctional conductivity. We suggest that this effect is specific for smooth muscle cells, which probably transmit constricting signals, and involves connexins other than Cx40. This mechanism may support the dilatory potency of NO by preventing the conduction of remote vasoconstrictions into areas with basal or activated NO release.
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Affiliation(s)
- Barbara Rodenwaldt
- Physiologisches Institut, Universität Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
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32
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Isakson BE, Kronke G, Kadl A, Leitinger N, Duling BR. Oxidized phospholipids alter vascular connexin expression, phosphorylation, and heterocellular communication. Arterioscler Thromb Vasc Biol 2006; 26:2216-21. [PMID: 16857951 DOI: 10.1161/01.atv.0000237608.19055.53] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE In endothelial cells (EC) and vascular smooth muscle cells (VSMC) from atherosclerotic mice, connexin (Cx) expression becomes distorted. Lipoprotein-derived phospholipid oxidation products (OxPAPC) play a critical role in atherosclerosis, and we hypothesized that they may act as trigger molecules causing the changes in connexin expression. METHODS AND RESULTS We applied OxPAPC to murine carotid arteries in vivo and vascular cell cocultures. OxPAPC applied to carotids induced an upregulation of both Cx37 and Cx43 in the VSMC. In EC, Cx43 was upregulated and Cx37 was downregulated, whereas Cx40 in EC remained constant. In the vascular cell coculture, OxPAPC caused similar changes in Cx37 and Cx43 but caused a decrease in Cx40 in EC and an elevation of Cx40 in VSMC. In the coculture model, OxPAPC treatment led to the selective disappearance of Cx40 at the myoendothelial junction. Biocytin dye transfer between EC and VSMC coupling was dramatically reduced by OxPAPC. The decrease in dye transfer after OxPAPC treatment was correlated with an increase in tyrosine 265 phosphorylation of Cx43, especially at the in vitro myoendothelial junction. CONCLUSIONS We conclude that OxPAPC could be responsible for the changes in connexin expression previously reported in atherosclerosis.
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MESH Headings
- Animals
- Blood Vessels/cytology
- Blood Vessels/drug effects
- Blood Vessels/metabolism
- Carotid Arteries/drug effects
- Carotid Arteries/metabolism
- Cell Communication/physiology
- Cells, Cultured
- Coculture Techniques
- Connexin 43/metabolism
- Connexins/metabolism
- Endothelial Cells/drug effects
- Endothelial Cells/metabolism
- Gap Junctions/drug effects
- Gap Junctions/metabolism
- Lysine/analogs & derivatives
- Lysine/pharmacokinetics
- Mice
- Mice, Inbred C57BL
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Permeability/drug effects
- Phosphatidylcholines/pharmacology
- Phosphorylation
- Gap Junction alpha-5 Protein
- Gap Junction alpha-4 Protein
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Affiliation(s)
- Brant E Isakson
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
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Yamawaki H, Iwai N. Mechanisms Underlying Nano-Sized Air-Pollution-Mediated Progression of Atherosclerosis Carbon Black Causes Cytotoxic Injury/Inflammation and Inhibits Cell Growth in Vascular Endothelial Cells. Circ J 2006; 70:129-40. [PMID: 16377937 DOI: 10.1253/circj.70.129] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Epidemiological studies indicate a significant link between exposure to environmental air pollution and mortality and morbidity from ischemic heart disease. Because nanoparticles can translocate into blood circulation, the present study aimed to clarify their direct effects on human vascular endothelial cells (ECs). METHODS AND RESULTS Human umbilical vein ECs (HUVECs) were treated with carbon black (CB), a component of diesel exhaust particles, for 24 h. CB induced cytotoxic morphological changes such as cytosolic vacuole formation, cell disorientation and decreased density. Lactate dehydrogenase assay revealed that CB induced cytotoxic injury in both the cells and plasma membranes. Proliferation assay showed that CB inhibited cell growth. Monocyte chemoattractant protein-1 but not vascular cell adhesion molecule-1 was induced by CB. CB reduced the expressions of connexin37 and endothelial nitric oxide (NO) synthase. Microarray analysis revealed the induction of pro-inflammatory molecules by CB. CONCLUSIONS The present results demonstrate for the first time that CB directly affects the endothelium, causing cytotoxic injury, inflammatory responses, and inhibition of cell growth. As EC injury/inflammation and membrane disintegration are related to the initiation of atherosclerosis, and NO is anti-atherogenic and anti-thrombogenic, the direct effects of nanoparticles on ECs may represent one mechanism behind environmental air pollution-mediated atherosclerosis and ischemic heart disease.
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Affiliation(s)
- Hideyuki Yamawaki
- Department of Epidemiology, Research Institute, National Cardiovascular Center, Suita, Japan
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Rignault S, Haefliger JA, Gasser D, Markert M, Nicod P, Liaudet L, Waeber B, Feihl F. Sepsis up-regulates the expression of connexin 40 in rat aortic endothelium. Crit Care Med 2005; 33:1302-10. [PMID: 15942348 DOI: 10.1097/01.ccm.0000165968.47343.0d] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE A distinctive feature of sepsis is a pleiotropic modification of membrane protein expression in the vascular endothelium, associated with diminished endothelium-dependent relaxation (endothelial dysfunction). In cultured endothelial cells, inflammatory stimuli alter expression of connexins (Cx), proteins that make up the gap junctions responsible for intercellular communication. In the present study, we tested whether the polymicrobial sepsis induced by cecal ligation and perforation in the rat alters the expression of the connexins present in the vascular endothelium (i.e., Cx37, Cx40, and Cx43). We also examined a possible association between such changes and endothelial dysfunction in this model. DESIGN Animal study, with two parallel groups. SETTING Animal research facility. SUBJECTS One hundred four male adult Wistar rats. INTERVENTIONS Rats underwent either cecal ligation and perforation to induce sepsis or a sham operation and were killed after a variable time, mostly 24 hrs. MEASUREMENTS AND MAIN RESULTS Experiments designed to test for the impact of sepsis on connexin expression disclosed a three-fold increase in Cx40 messenger RNA and protein in the aorta, an effect that peaked at 24 hrs after cecal ligation and perforation, was specific to this connexin (i.e., levels of Cx37 and Cx43 did not vary), and was restricted to the aortic endothelium. Experiments designed to test the permeability of interendothelial gap junctions using the scrape-loading method did not show a change in function in the septic group. Finally, a time-course study was designed to test for a possible association of enhanced Cx40 expression with endothelial dysfunction. Endothelium-dependent relaxation was diminished in rings of aorta when harvested from septic rats before (6 hrs after surgery) but not at the time when enhanced Cx40 expression occurred (12 and 24 hrs). CONCLUSION In this experimental model, recovery from an early transient dysfunction of the aortic endothelium is associated with an enhanced expression of aortic endothelial Cx40.
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Affiliation(s)
- Stéphanie Rignault
- Division de Physiopathologie Clinique, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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