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Okamoto T, Park EJ, Kawamoto E, Usuda H, Wada K, Taguchi A, Shimaoka M. Endothelial connexin-integrin crosstalk in vascular inflammation. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166168. [PMID: 33991620 DOI: 10.1016/j.bbadis.2021.166168] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/18/2021] [Accepted: 05/02/2021] [Indexed: 02/06/2023]
Abstract
Cardiovascular diseases including blood vessel disorders represent a major cause of death globally. The essential roles played by local and systemic vascular inflammation in the pathogenesis of cardiovascular diseases have been increasingly recognized. Vascular inflammation triggers the aberrant activation of endothelial cells, which leads to the functional and structural abnormalities in vascular vessels. In addition to humoral mediators such as pro-inflammatory cytokines and prostaglandins, the alteration of physical and mechanical microenvironment - including vascular stiffness and shear stress - modify the gene expression profiles and metabolic profiles of endothelial cells via mechano-transduction pathways, thereby contributing to the pathogenesis of vessel disorders. Notably, connexins and integrins crosstalk each other in response to the mechanical stress, and, thereby, play an important role in regulating the mechano-transduction of endothelial cells. Here, we provide an overview on how the inter-play between connexins and integrins in endothelial cells unfold during the mechano-transduction in vascular inflammation.
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Affiliation(s)
- Takayuki Okamoto
- Department of Pharmacology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-city, Shimane 693-8501, Japan.
| | - Eun Jeong Park
- Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu-city, Mie 514-8507, Japan
| | - Eiji Kawamoto
- Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu-city, Mie 514-8507, Japan; Department of Emergency and Disaster Medicine, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu-city, Mie 514-8507, Japan
| | - Haruki Usuda
- Department of Pharmacology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-city, Shimane 693-8501, Japan
| | - Koichiro Wada
- Department of Pharmacology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-city, Shimane 693-8501, Japan
| | - Akihiko Taguchi
- Department of Regenerative Medicine Research, Foundation for Biomedical Research and Innovation at Kobe, 2-2 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Motomu Shimaoka
- Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu-city, Mie 514-8507, Japan.
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2
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Allahverdian S, Chaabane C, Boukais K, Francis GA, Bochaton-Piallat ML. Smooth muscle cell fate and plasticity in atherosclerosis. Cardiovasc Res 2019; 114:540-550. [PMID: 29385543 DOI: 10.1093/cvr/cvy022] [Citation(s) in RCA: 300] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/22/2018] [Indexed: 12/21/2022] Open
Abstract
Current knowledge suggests that intimal smooth muscle cells (SMCs) in native atherosclerotic plaque derive mainly from the medial arterial layer. During this process, SMCs undergo complex structural and functional changes giving rise to a broad spectrum of phenotypes. Classically, intimal SMCs are described as dedifferentiated/synthetic SMCs, a phenotype characterized by reduced expression of contractile proteins. Intimal SMCs are considered to have a beneficial role by contributing to the fibrous cap and thereby stabilizing atherosclerotic plaque. However, intimal SMCs can lose their properties to such an extent that they become hard to identify, contribute significantly to the foam cell population, and acquire inflammatory-like cell features. This review highlights mechanisms of SMC plasticity in different stages of native atherosclerotic plaque formation, their potential for monoclonal or oligoclonal expansion, as well as recent findings demonstrating the underestimated deleterious role of SMCs in this disease.
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Affiliation(s)
- Sima Allahverdian
- Department of Medicine, Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, Room 166 Burrard Building, St Paul's Hospital, 1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada
| | - Chiraz Chaabane
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel Servet-1, 1211 Geneva 4, Switzerland
| | - Kamel Boukais
- Department of Medicine, Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, Room 166 Burrard Building, St Paul's Hospital, 1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada
| | - Gordon A Francis
- Department of Medicine, Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, Room 166 Burrard Building, St Paul's Hospital, 1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada
| | - Marie-Luce Bochaton-Piallat
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel Servet-1, 1211 Geneva 4, Switzerland
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Chen L, Chen Z, Ge M, Tang O, Cheng Y, Zhou H, Shen Y, Qin F. Monocytic cell junction proteins serve important roles in atherosclerosis via the endoglin pathway. Mol Med Rep 2017; 16:6750-6756. [PMID: 28901429 PMCID: PMC5865831 DOI: 10.3892/mmr.2017.7444] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 06/15/2017] [Indexed: 01/22/2023] Open
Abstract
The formation of atherosclerosis is recognized to be caused by multiple factors including pathogenesis in monocytes during inflammation. The current study provided evidence that monocytic junctions were significantly altered in patients with atherosclerosis, which suggested an association between cell junctions and atherosclerosis. Claudin‑1, occludin‑1 and ZO‑1 were significantly enhanced in atherosclerosis, indicating that the tight junction pathway was activated during the pathogenesis of atherosclerosis. In addition, the gene expression of 5 connexin members involved in the gap junction pathway were quantified, indicating that connexin 43 and 46 were significantly up‑regulated in atherosclerosis. Furthermore, inflammatory factors including endoglin and SMAD were observed, suggesting that immune regulative factors were down‑regulated in this pathway. Silicon‑based analysis additionally identified that connexins and tight junctions were altered in association with monocytic inflammation regulations, endoglin pathway. The results imply that reduced expression of the immune regulation pathway in monocytes is correlated with the generation of gap junctions and tight junctions which serve important roles in atherosclerosis.
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Affiliation(s)
- Lina Chen
- Department of Cardiology, Shaoxing Second Hospital, Shaoxing, Zhejiang 312000, P.R. China
| | - Zhongliang Chen
- Department of Cardiology, Shaoxing Second Hospital, Shaoxing, Zhejiang 312000, P.R. China
| | - Menghua Ge
- Department of Cardiology, Shaoxing Second Hospital, Shaoxing, Zhejiang 312000, P.R. China
| | - Oushan Tang
- Department of Cardiology, Shaoxing Second Hospital, Shaoxing, Zhejiang 312000, P.R. China
| | - Yinhong Cheng
- Department of Cardiology, Shaoxing Second Hospital, Shaoxing, Zhejiang 312000, P.R. China
| | - Haoliang Zhou
- Department of Cardiology, Shaoxing Second Hospital, Shaoxing, Zhejiang 312000, P.R. China
| | - Yu Shen
- Department of Cardiology, Shaoxing Second Hospital, Shaoxing, Zhejiang 312000, P.R. China
| | - Fengming Qin
- Department of Cardiology, Shaoxing Second Hospital, Shaoxing, Zhejiang 312000, P.R. China
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4
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Cellular mechanisms of human atherosclerosis: Role of cell-to-cell communications in subendothelial cell functions. Tissue Cell 2015; 48:25-34. [PMID: 26747411 DOI: 10.1016/j.tice.2015.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Revised: 11/09/2015] [Accepted: 11/09/2015] [Indexed: 12/16/2022]
Abstract
The present study was undertaken in order to extend of our earlier work, focusing on the analysis of roles of cell-to-cell communications in the regulation of the subendothelial cell function. In present study, we have found that the expression of connexin43 (Cx43) is dramatically reduced in human atherosclerotic lesions, compared with undiseased intima. In atherosclerotic lesions, the number of so-called 'connexin plaques' was found to be lower in lipid-laden cells than in cells which were free from lipid inclusions. In primary cell culture, subendothelial intimal cells tended to create multicellular structures in the form of clusters. Cluster creation was accompanied by the formation of gap junctions between cells; the degree of gap junctional communication correlated with the density of cells in culture. We found that atherosclerosis-related processes such as DNA synthesis, protein synthesis and accumulation of intracellular cholesterol correlated with the degree of cell-to-cell communication. The relation of DNA and protein synthesis with cell-to-cell communication could be described as "bell-shaped". We further incubated cells, cultured from undiseased subendothelial intima, with various forms of modified LDL causing intracellular cholesterol accumulation. After the incubation of intimal cells with modified LDL, intercellular communication has "dropped" considerably. The findings indicate that intracellular lipid accumulation might be a reason for a decrease of the number of gap junctions. The findings also suggest that the disintegration of cellular network is associated with foam cell formation, the process known as a key event of atherogenesis.
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Chaabane C, Coen M, Bochaton-Piallat ML. Smooth muscle cell phenotypic switch: implications for foam cell formation. Curr Opin Lipidol 2014; 25:374-9. [PMID: 25110900 DOI: 10.1097/mol.0000000000000113] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE OF REVIEW It is well accepted that LDLs and its modified form oxidized-LDL (ox-LDL) play a major role in the development of atherosclerosis and foam cell formation. Whereas the majority of these cells have been demonstrated to be derived from macrophages, smooth muscle cells (SMCs) give rise to a significant number of foam cells as well. During atherosclerotic plaque formation, SMCs switch from a contractile to a synthetic phenotype. The contribution of this process to foam cell formation is still not well understood. RECENT FINDINGS It has been confirmed that a large proportion of foam cells in human atherosclerotic plaques and in experimental intimal thickening arise from SMCs. SMC-derived foam cells express receptors involved in ox-LDL uptake and HDL reverse transport. In-vitro studies show that treatment of SMCs with ox-LDL induces typical foam-cell formation; this process is associated with a transition of SMCs toward a synthetic phenotype. SUMMARY This review summarizes data regarding the phenotypic switch of arterial SMCs within atherosclerotic lesion and their contribution to intimal foam cell formation.
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Affiliation(s)
- Chiraz Chaabane
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Begandt D, Bader A, Gerhard L, Lindner J, Dreyer L, Schlingmann B, Ngezahayo A. Dipyridamole-related enhancement of gap junction coupling in the GM-7373 aortic endothelial cells correlates with an increase in the amount of connexin 43 mRNA and protein as well as gap junction plaques. J Bioenerg Biomembr 2013; 45:409-19. [PMID: 23800832 DOI: 10.1007/s10863-013-9518-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 06/14/2013] [Indexed: 11/28/2022]
Abstract
Previous data showed that dipyridamole enhanced gap junction coupling in vascular endothelial and smooth muscle cell lines by a cAMP-dependent mechanism. The present study investigates the level at which dipyridamole affects gap junction coupling. In the GM-7373 endothelial cell line, scrape loading/dye transfer experiments revealed a rapid increase in gap junction coupling induced during the first 6 h of dipyridamole treatment, followed by a slow increase induced by further incubation. Immunostaining analyses showed that the rapid enhancement of gap junction coupling correlated with an increased amount of Cx43 gap junction plaques and a reduced amount of Cx43 containing vesicles, while the amount of Cx43 mRNA or protein was not changed during this period, as found by semiquantitative RT-PCR and Western blot. Additionally, brefeldin A did not block this short-term-induced enhancement of gap junction coupling. Along with the dipyridamole-induced long-term enhancement of gap junction coupling, the amount of Cx43 mRNA and protein additionally to the amount of Cx43 gap junction plaques were increased. Furthermore, the anti-Cx43 antibody detected only two bands at 42 kDa and 44 kDa in control cells and cells treated with dipyridamole for 6 h, while long-term dipyridamole-treated cells showed a third band at 46 kDa. We propose that a dipyridamole-induced cAMP synthesis increased gap junction coupling in the GM-7373 endothelial cell line at different levels: the short-term effect is related to already oligomerised connexins beyond the Golgi apparatus and the long-term effect involves new expression and synthesis as well as posttranslational modification of Cx43.
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Affiliation(s)
- Daniela Begandt
- Institute of Biophysics, Leibniz University Hannover, Herrenhäuserstr. 2, D-30419 Hannover, Germany
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7
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Abstract
Vascular walls change their dimension and mechanical properties in response to injury such as balloon angioplasty and endovascular stent implantation. Placement of bare metal stents induces neointimal proliferation/restenosis which progresses through different phases of repair with time involving a cascade of cellular reactions. These phases just like wound healing comprise distinct steps consisting of thrombosis, inflammation, proliferation, and migration followed by remodelling. It is noteworthy that animals show a rapid progression of healing after stent deployment compared with man. During stenting, endothelial cells are partially to completely destroyed or crushed along with medial wall injury and stretching promoting activation of platelets, and thrombus formation accompanied by inflammatory reaction. Macrophages and platelets play a central role through the release of cytokines and growth factors that induce vascular smooth muscle cell accumulation within the intima. Smooth muscle cells undergo complex phenotypic changes including migration and proliferation from the media towards the intima, and transition from a contractile to a synthetic phenotype; the molecular mechanisms responsible for this change are highlighted in this review. Since studies in animals and man show that smooth muscle cells play a dominant role in restenosis, drugs like rapamycin and paclitaxel have been coated on stent with polymers to allow local slow release of drugs, which have resulted in dramatic reduction of restenosis that was once the Achilles' heel of interventional cardiologists.
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Affiliation(s)
- Chiraz Chaabane
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel Servet -1, 1211 Geneva 4, Switzerland
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8
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Begandt D, Bader A, Dreyer L, Eisert N, Reeck T, Ngezahayo A. Biphasic increase of gap junction coupling induced by dipyridamole in the rat aortic A-10 vascular smooth muscle cell line. J Cell Commun Signal 2013; 7:151-60. [PMID: 23483357 DOI: 10.1007/s12079-013-0196-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 02/18/2013] [Indexed: 12/11/2022] Open
Abstract
The rat aortic smooth muscle cell line A-10 was used to investigate the effect of dipyridamole on the gap junction coupling of smooth muscle cells. The scrape loading/dye transfer (SL/DT) technique revealed that dipyridamole concentrations between 5 μM and 100 μM significantly increased gap junction coupling. The adenosine receptor antagonist MRS 1754, as well as the PKA inhibitors Rp-cAMPS and H-89 were able to inhibit the dipyridamole-related increase in coupling, while forskolin and Br-cAMP also induced an enhancement of the gap junction coupling. Regarding the time-dependent behaviour of dipyridamole, a short-term effect characterised by an oscillatory reaction was observed for application times of less than 5 h, while applications times of at least 6 h resulted in a long-term effect, characterised by a constant increase of gap junction coupling to its maximum levels. This increase was not altered by prolonged presence of dipyridamole. In parallel, a short application of dipyridamole for at least 15 min was found to be sufficient to evoke the long-term effect measured 6 h after drug washout. We propose that in both the short-term and long-term effect, cAMP-related pathways are activated. The short-term phase could be related to an oscillatory cAMP effect, which might directly affect connexin trafficking, assembly and/or gap junction gating. The long-term effect is most likely related to the new expression and synthesis of connexins. With previous data from a bovine aortic endothelial cell line, the present results show that gap junction coupling of vascular cells is a target for dipyridamole.
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Affiliation(s)
- Daniela Begandt
- Institute of Biophysics, Leibniz University Hannover, Herrenhäuserstr. 2, 30419, Hannover, Germany
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9
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Stancu CS, Toma L, Sima AV. Dual role of lipoproteins in endothelial cell dysfunction in atherosclerosis. Cell Tissue Res 2012; 349:433-46. [DOI: 10.1007/s00441-012-1437-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 04/12/2012] [Indexed: 12/28/2022]
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10
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Zhang S, Hong M, Gao Y. Effect of oxidized LDL on the expression of connexins in cultured human umbilical-vein endothelial cells. Cell Biol Int 2012; 36:497-502. [PMID: 22335207 DOI: 10.1042/cbi20110466] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The role of connexins in atherogenesis has attracted increasing attention in recent years; however, whether oxidized LDL (low density lipoprotein) is one of the pro-atherosclerotic factors that can influence the expression of endothelial connexins remains unclear. To investigate the effect of oxidized LDL on the gene expression of the gap junction proteins connexin37, connexin40 and connexin43 in cultured HUVEC (human umbilical-vein endothelial cells) in vitro, HUVEC were cultured and divided into groups before being stimulated with various concentrations of oxidized LDL for different times. mRNA expression of connexin37, connexin40 and connexin43 in each group were determined semi-quantitatively by RT-PCR (reverse transcription-PCR), while protein expression of the three connexins was investigated by immunocytochemical staining. Various concentrations of oxidized LDL down-regulated mRNA and protein expression of connexin37, and up-regulated the expression of connexin40 and connexin43. Time-dependent dynamic alterations of the mRNA expression levels of connexin37, connexin40 and connexin43 were also found in HUVEC stimulated by oxidized LDL. We conclude that oxidized LDL can change the expression of connexin genes in cultured HUVEC within a short period, and thus may be involved in the pro-atherosclerotic effect of oxidized LDL.
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Affiliation(s)
- Shunrong Zhang
- Geriatric Department, Hangzhou First Peoples Hospital, Hangzhou, Peoples Republic of China.
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11
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Abstract
The appearance of multicellular organisms imposed the development of several mechanisms for cell-to-cell communication, whereby different types of cells coordinate their function. Some of these mechanisms depend on the intercellular diffusion of signal molecules in the extracellular spaces, whereas others require cell-to-cell contact. Among the latter mechanisms, those provided by the proteins of the connexin family are widespread in most tissues. Connexin signaling is achieved via direct exchanges of cytosolic molecules between adjacent cells at gap junctions, for cell-to-cell coupling, and possibly also involves the formation of membrane "hemi-channels," for the extracellular release of cytosolic signals, direct interactions between connexins and other cell proteins, and coordinated influence on the expression of multiple genes. Connexin signaling appears to be an obligatory attribute of all multicellular exocrine and endocrine glands. Specifically, the experimental evidence we review here points to a direct participation of the Cx36 isoform in the function of the insulin-producing β-cells of the endocrine pancreas, and of the Cx40 isoform in the function of the renin-producing juxtaglomerular epithelioid cells of the kidney cortex.
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Affiliation(s)
- Domenico Bosco
- Department of Surgery, University of Geneva Medical School, Geneva, Switzerland
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Tkachuk N, Tkachuk S, Patecki M, Kusch A, Korenbaum E, Haller H, Dumler I. The tight junction protein ZO-2 and Janus kinase 1 mediate intercellular communications in vascular smooth muscle cells. Biochem Biophys Res Commun 2011; 410:531-6. [PMID: 21679692 DOI: 10.1016/j.bbrc.2011.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 06/01/2011] [Indexed: 12/22/2022]
Abstract
Recent evidence points to a multifunctional role of ZO-2, the tight junction protein of the MAGUK (membrane-associated guanylate kinase-like) family. Though ZO-2 has been found in cell types lacking tight junction structures, such as vascular smooth muscle cells (VSMC), little is known about ZO-2 function in these cells. We provide evidence that ZO-2 mediates specific homotypic cell-to-cell contacts between VSMC. Using mass spectrometry we found that ZO-2 is associated with the non-receptor tyrosine kinase Jak1. By generating specific ZO-2 constructs we further found that the N-terminal fragment of ZO-2 molecule is responsible for this interaction. Adenovirus-based expression of Jak1 inactive mutant demonstrated that Jak1 mediates ZO-2 tyrosine phosphorylation. By means of RNA silencing, expression of Jak1 mutant form and fluorescently labeled ZO-2 fusion protein we further specified that active Jak1, but not Jak1 inactive mutant, mediates ZO-2 localization to the sites of intercellular contacts. We identified the urokinase receptor uPAR as a pre-requisite for these cellular events. Functional requirement of the revealed signaling complex for VSMC network formation was confirmed in experiments using Matrigel and in contraction assay. Our findings imply involvement of the ZO-2 tight junction independent signaling complex containing Jak1 and uPAR in VSMC intercellular communications. This mechanism may contribute to vascular remodeling in occlusive cardiovascular diseases and in arteriogenesis.
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Affiliation(s)
- Natalia Tkachuk
- Department of Nephrology, Hannover Medical School, Hannover D-30625, Germany
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13
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Abstract
Atherosclerosis and thrombosis associated with the rupture of vulnerable plaque are the main causes of cardiovascular events, including acute coronary syndrome. Low-density lipoprotein (LDL) plays a key role in the pathogenesis of atherothrombotic processes. LDLs modify the antithrombotic properties of the vascular endothelium and change vessel contractility by reducing the availability of endothelial nitric oxide and activating proinflammatory signaling pathways. In addition, LDLs also influence the functions and interactions of cells present in atherosclerotic lesions, whether they come from the circulation or are resident in vessel walls. In fact, LDLs entering affected vessels undergo modifications (e.g. oxidation, aggregation and glycosylation) that potentiate their atherogenic properties. Once modified, these intravascular LDLs promote the formation of foam cells derived from smooth muscle cells and macrophages, thereby increasing the vulnerability of atherosclerotic plaque. Moreover, they also increase the thrombogenicity of both plaque and blood, in which circulating tissue factor levels are raised and platelet reactivity is enhanced. This review focuses on the importance of native and modified LDL for the pathogenesis of atherothrombosis. It also discusses current studies on LDL and its effects on the actions of vascular cells and blood cells, particularly platelets, and considers novel potential therapeutic targets.
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Affiliation(s)
- Lina Badimón
- Centro de Investigación Cardiovascular, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau Barcelona, España.
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14
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Dipyridamole increases gap junction coupling in bovine GM-7373 aortic endothelial cells by a cAMP-protein kinase A dependent pathway. J Bioenerg Biomembr 2010; 42:79-84. [DOI: 10.1007/s10863-009-9262-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Accepted: 11/23/2009] [Indexed: 01/24/2023]
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16
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Inai T, Shibata Y. Heterogeneous expression of endothelial connexin (Cx) 37, Cx40, and Cx43 in rat large veins. Anat Sci Int 2009; 84:237-45. [PMID: 19322632 DOI: 10.1007/s12565-009-0029-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Accepted: 12/25/2008] [Indexed: 11/25/2022]
Abstract
Gap junctions are clusters of transmembrane protein channels for intercellular communication and are composed of connexin (Cx). The vascular endothelial cells express Cx37, Cx40, and Cx43. We herein examined the spatial distribution of the endothelial connexins Cx37, Cx40, and Cx43 in rat large veins including the cranial vena cava, thoracic section of the caudal vena cava, and abdominal section of the caudal vena cava. We also examined the mean size of the endothelial cells and quantified the protein expression levels of the endothelial connexins. We found that the large veins heterogeneously expressed Cx37, Cx40, and Cx43 as follows: Cx40 > Cx37 > > Cx43 in the cranial vena cava, Cx37 > Cx43 > > Cx40 in the thoracic section of the caudal vena cava, and Cx40 > Cx43 > > Cx37 in the abdominal section of the caudal vena cava. Double immunostaining of two of the endothelial connexins revealed that the gap-junction plaques were composed of various combinations of endothelial connexins. The mean size of the endothelial cells was large, moderate, or small in the cranial vena cava, the abdominal section of the caudal vena cava, or the thoracic section of the caudal vena cava, respectively. The heterogeneity of the endothelial cells of the rat large veins in terms of the connexin expression suggests that the endothelial cells are differently coupled in the large veins. The present data are useful for investigating, for example, disease-related alterations in expression of endothelial connexins in large veins.
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Affiliation(s)
- Tetsuichiro Inai
- Department of Developmental Molecular Anatomy, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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17
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Orellana JA, Sáez PJ, Shoji KF, Schalper KA, Palacios-Prado N, Velarde V, Giaume C, Bennett MVL, Sáez JC. Modulation of brain hemichannels and gap junction channels by pro-inflammatory agents and their possible role in neurodegeneration. Antioxid Redox Signal 2009; 11:369-99. [PMID: 18816186 PMCID: PMC2713807 DOI: 10.1089/ars.2008.2130] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In normal brain, neurons, astrocytes, and oligodendrocytes, the most abundant and active cells express pannexins and connexins, protein subunits of two families forming membrane channels. Most available evidence indicates that in mammals endogenously expressed pannexins form only hemichannels and connexins form both gap junction channels and hemichannels. Whereas gap junction channels connect the cytoplasm of contacting cells and coordinate electric and metabolic activity, hemichannels communicate the intra- and extracellular compartments and serve as a diffusional pathway for ions and small molecules. A subthreshold stimulation by acute pathological threatening conditions (e.g., global ischemia subthreshold for cell death) enhances neuronal Cx36 and glial Cx43 hemichannel activity, favoring ATP release and generation of preconditioning. If the stimulus is sufficiently deleterious, microglia become overactivated and release bioactive molecules that increase the activity of hemichannels and reduce gap junctional communication in astroglial networks, depriving neurons of astrocytic protective functions, and further reducing neuronal viability. Continuous glial activation triggered by low levels of anomalous proteins expressed in several neurodegenerative diseases induce glial hemichannel and gap junction channel disorders similar to those of acute inflammatory responses triggered by ischemia or infectious diseases. These changes are likely to occur in diverse cell types of the CNS and contribute to neurodegeneration during inflammatory process.
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Affiliation(s)
- Juan A Orellana
- Departamento de Ciencias Fisiológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
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18
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Scemes E, Spray DC, Meda P. Connexins, pannexins, innexins: novel roles of "hemi-channels". Pflugers Arch 2008; 457:1207-26. [PMID: 18853183 DOI: 10.1007/s00424-008-0591-5] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Accepted: 09/17/2008] [Indexed: 12/11/2022]
Affiliation(s)
- Eliana Scemes
- The Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA
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19
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Sima AV, Stancu CS, Simionescu M. Vascular endothelium in atherosclerosis. Cell Tissue Res 2008; 335:191-203. [PMID: 18797930 DOI: 10.1007/s00441-008-0678-5] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Accepted: 08/18/2008] [Indexed: 12/18/2022]
Abstract
Their strategic location between blood and tissue and their constitutive properties allow endothelial cells (EC) to monitor the transport of plasma molecules, by employing bidirectional receptor-mediated and receptor-independent transcytosis and endocytosis, and to regulate vascular tone, cellular cholesterol and lipid homeostasis. These cells are also involved in signal transduction, immunity, inflammation and haemostasis. Cardiovascular risk factors, such as hyperlipaemia/dyslipidaemia trigger the molecular machinery of EC to respond to insults by modulation of their constitutive functions followed by dysfunction and ultimately by injury and apoptosis. The gradual activation of EC consists initially in the modulation of two constitutive functions: (1) permeability, i.e. increased transcytosis of lipoproteins, and (2) biosynthetic activity, i.e. enhanced synthesis of the basement membrane and extracellular matrix. The increased transcytosis and the reduced efflux of beta-lipoproteins (betaLp) lead to their retention within the endothelial hyperplasic basal lamina as modified lipoproteins (MLp) and to their subsequent alteration (oxidation, glycation, enzymatic modifications). MLp generate chemoattractant and inflammatory molecules, triggering EC dysfunction (appearance of new adhesion molecules, secretion of chemokines, cytokines), characterised by monocyte recruitment, adhesion, diapedesis and residence within the subendothelium. In time, EC in the athero-prone areas alter their net negative surface charge, losing their non-thrombogenic ability, become loaded with lipid droplets and turn into foam cells. Prolonged and/or repeated exposure to cardiovascular risk factors can ultimately exhaust the protective effect of the endogenous anti-inflammatory system within EC. As a consequence, EC may progress to senescence, lose their integrity and detach into the circulation.
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Affiliation(s)
- Anca V Sima
- Institute of Cellular Biology and Pathology Nicolae Simionescu, 8 B.P.Hasdeu Street, 050568 Bucharest, Romania.
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The role of phospholipid oxidation products in inflammatory and autoimmune diseases: evidence from animal models and in humans. Subcell Biochem 2008; 49:325-50. [PMID: 18751917 DOI: 10.1007/978-1-4020-8830-8_12] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Since the discovery of oxidized phospholipids (OxPL) and their implication as modulators of inflammation in cardiovascular disease, roles for these lipid oxidation products have been suggested in many other disease settings. Lipid oxidation products accumulate in inflamed and oxidatively damaged tissue, where they are derived from oxidative modification of lipoproteins, but also from membranes of cells undergoing apoptosis. Thus, increased oxidative stress as well as decreased clearance of apoptotic cells has been implied to contribute to accumulation of OxPL in chronically inflamed tissues.A central role for OxPL in disease states associated with dyslipedemia, including atherosclerosis, diabetes and its complications, metabolic syndrome, and renal insufficiency, as well as general prothrombotic states, has been proposed. In addition, in organs which are constantly exposed to oxidative stress, including lung, skin, and eyes, increased levels of OxPL are suggested to contribute to inflammatory conditions. Moreover, accumulation of OxPL causes general immunmodulation and may lead to autoimmune diseases. Evidence is accumulating that OxPL play a role in lupus erythematosus, antiphospholipid syndrome, and rheumatoid arthritis. Last but not least, a role for OxPL in neurological disorders including multiple sclerosis (MS), Alzheimer's and Parkinson's disease has been suggested.This chapter will summarize recent findings obtained in animal models and from studies in humans that indicate that formation of OxPL represents a general mechanism that may play a major role in chronic inflammatory and autoimmune diseases.
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Gupta PK, Subramani J, Leo MDM, Sikarwar AS, Parida S, Prakash VR, Mishra SK. Role of voltage-dependent potassium channels and myo-endothelial gap junctions in 4-aminopyridine-induced inhibition of acetylcholine relaxation in rat carotid artery. Eur J Pharmacol 2008; 591:171-6. [PMID: 18577383 DOI: 10.1016/j.ejphar.2008.06.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 05/27/2008] [Accepted: 06/08/2008] [Indexed: 11/18/2022]
Abstract
The present study examined the role of voltage-gated potassium (K(v)) channels and myo-endothelial gap junctions in 4-aminopyridine-induced inhibition of acetylcholine-evoked endothelium-dependent relaxation and NO release in the rat carotid artery. The acetylcholine-induced relaxation was drastically inhibited by 94% and 82%, respectively in the presence of either 100 microM N(G)-nitro-l-arginine methyl ester (L-NAME) or 10 microM 1H-[1,2,4]oxadiazolo[4,3,a]quinoxalin-1-one (ODQ), while it was abolished following endothelium removal. 4-aminopyridine (1 mM), a preferential blocker of the K(v) channels significantly decreased the vasodilator potency, as well as efficacy of acetylcholine (pD(2) 5.7+/-0.09, R(max) 86.1+/-3.5% versus control 6.7+/-0.10 R(max) 106+/-3.5%, n=6), but had no effect on the relaxations elicited by either sodium nitroprusside (SNP) or 8-bromo-cyclic guanosine monophosphate (8-Br-cGMP). 4-AP (1 mM) also inhibited acetylcholine (3 microM)-stimulated nitrite release in the carotid artery segments (99.4+/-4.93 pmol/mg tissue weight wt; n=6 versus control 123.8+/-7.43 pmol/mg tissue weight wt, n=6). 18alpha-glycyrrhetinic acid (18alpha-GA, 5 microM), a gap junction blocker, completely prevented the inhibition of acetylcholine-induced relaxation, as well as nitrite release by 4-AP. In the pulmonary artery, however antagonism of acetylcholine-evoked relaxation by 4-AP was not reversed by 18alpha-GA. These results suggest that 4-AP-induced inhibition of endothelium-dependent relaxation and NO release involves electrical coupling between vascular smooth muscle and endothelial cells via myo-endothelial gap junctions in the rat carotid artery, but not in the pulmonary artery. Further, direct activation of 4-AP-sensitive vascular K(v) channels by endothelium-derived NO is not evident in the carotid blood vessel, while this appears to be an important mechanism of acetylcholine-induced relaxation in the pulmonary artery.
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Affiliation(s)
- Praveen K Gupta
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India-243122
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