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Espitia Pinzón N, Brevé JJP, Bol JGJM, Drukarch B, Baron W, van Dam AM. Tissue transglutaminase in astrocytes is enhanced by inflammatory mediators and is involved in the formation of fibronectin fibril-like structures. J Neuroinflammation 2017; 14:260. [PMID: 29282083 PMCID: PMC5745633 DOI: 10.1186/s12974-017-1031-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 12/11/2017] [Indexed: 02/07/2023] Open
Abstract
Background During multiple sclerosis (MS) lesion formation, inflammatory mediators are produced by microglial cells and invading leukocytes. Subsequently, hypertrophic astrocytes fill the lesion and produce extracellular matrix (ECM) proteins that together form the astroglial scar. This is beneficial because it seals off the site of central nervous system (CNS) damage. However, astroglial scarring also forms an obstacle that inhibits remyelination of brain lesions. This is possibly an important cause for incomplete remyelination of the CNS in early stage MS patients and for failure of remyelination when the disease progresses. Tissue transglutaminase (TG2), a Ca2+-dependent enzyme that can cross-link proteins, appears in astrocytes in inflammatory MS lesions and may contribute to the rearrangement of ECM protein deposition and aggregation. Methods The effect of different inflammatory mediators on TG2 and fibronectin, an ECM protein, protein levels was examined in primary rat microglia and astrocytes by western blotting. Also, TG2 activity was analyzed in primary rat astrocytes by a TG activity assay. To determine the role of TG2 in the deposition and cross-linking of fibronectin, a TG2 inhibitor and TG2 knockdown astrocytes were used. Results Our data show that under inflammatory conditions in vitro, TG2 production is enhanced in astrocytes and microglia. We observed that in particular, astrocytes produce fibronectin that can be cross-linked and aggregated by exogenous TG2. Moreover, inflammatory stimulus-induced endogenously produced TG2 is involved in the appearance of morphological fibril-like fibronectin deposits but does not lead to cross-linked fibronectin aggregates. Conclusions Our in vitro observations suggest that during MS lesion formation, when inflammatory mediators are produced, astrocyte-derived TG2 may contribute to ECM rearrangement, and subsequent astroglial scarring. Electronic supplementary material The online version of this article (10.1186/s12974-017-1031-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nathaly Espitia Pinzón
- Department Anatomy and Neurosciences, VU University Medical Center, Amsterdam Neuroscience, De Boelelaan 1108, 1081, HZ, Amsterdam, The Netherlands
| | - John J P Brevé
- Department Anatomy and Neurosciences, VU University Medical Center, Amsterdam Neuroscience, De Boelelaan 1108, 1081, HZ, Amsterdam, The Netherlands
| | - John G J M Bol
- Department Anatomy and Neurosciences, VU University Medical Center, Amsterdam Neuroscience, De Boelelaan 1108, 1081, HZ, Amsterdam, The Netherlands
| | - Benjamin Drukarch
- Department Anatomy and Neurosciences, VU University Medical Center, Amsterdam Neuroscience, De Boelelaan 1108, 1081, HZ, Amsterdam, The Netherlands
| | - Wia Baron
- Department of Cell Biology, University Medical Center Groningen, Groningen, The Netherlands
| | - Anne-Marie van Dam
- Department Anatomy and Neurosciences, VU University Medical Center, Amsterdam Neuroscience, De Boelelaan 1108, 1081, HZ, Amsterdam, The Netherlands.
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Ko KW, Choi B, Park S, Arai Y, Choi WC, Lee JM, Bae H, Han IB, Lee SH. Down-Regulation of Transglutaminase 2 Stimulates Redifferentiation of Dedifferentiated Chondrocytes through Enhancing Glucose Metabolism. Int J Mol Sci 2017; 18:E2359. [PMID: 29112123 PMCID: PMC5713328 DOI: 10.3390/ijms18112359] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/28/2017] [Accepted: 10/30/2017] [Indexed: 12/27/2022] Open
Abstract
Expansion of chondrocytes for repair of articular cartilage can lead to dedifferentiation, making it difficult to obtain a sufficient quantity of chondrocytes. Although previous studies have suggested that culture in a three-dimensional environment induces redifferentiation of dedifferentiated chondrocytes, its underlying mechanisms are still poorly understood in terms of metabolism compared with a two-dimensional environment. In this study, we demonstrate that attenuation of transglutaminase 2 (TG2), a multifunctional enzyme, stimulates redifferentiation of dedifferentiated chondrocytes. Fibroblast-like morphological changes increased as TG2 expression increased in passage-dependent manner. When dedifferentiated chondrocytes were cultured in a pellet culture system, TG2 expression was reduced and glycolytic enzyme expression up-regulated. Previous studies demonstrated that TG2 influences energy metabolism, and impaired glycolytic metabolism causes chondrocyte dedifferentiation. Interestingly, TG2 knockdown improved chondrogenic gene expression, glycolytic enzyme expression, and lactate production in a monolayer culture system. Taken together, down-regulation of TG2 is involved in redifferentiaton of dedifferentiated chondrocytes through enhancing glucose metabolism.
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Affiliation(s)
- Kyoung-Won Ko
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si 13488, Korea.
| | - Bogyu Choi
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si 13488, Korea.
| | - Sunghyun Park
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si 13488, Korea.
| | - Yoshie Arai
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si 13488, Korea.
| | - Won Chul Choi
- Department of Orthopedic Surgery, Bundang Medical Center, CHA University, Seongnam-si 13496, Gyeonggi-do, Korea.
| | - Joong-Myung Lee
- Department of Orthopedic Surgery, Bundang Medical Center, CHA University, Seongnam-si 13496, Gyeonggi-do, Korea.
| | - Hojae Bae
- College of Animal Bioscience and Technology, Department of Bioindustrial Technologies, Konkuk University, Seoul 05029, Korea.
| | - In-Bo Han
- Department of Neurosurgery, CHA University, CHA Bundang Medical Center, Seongnam-si 13496, Korea.
| | - Soo-Hong Lee
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si 13488, Korea.
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3
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Influenza Virus Infection Induces Platelet-Endothelial Adhesion Which Contributes to Lung Injury. J Virol 2015; 90:1812-23. [PMID: 26637453 DOI: 10.1128/jvi.02599-15] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 11/25/2015] [Indexed: 01/13/2023] Open
Abstract
Lung injury after influenza infection is characterized by increased permeability of the lung microvasculature, culminating in acute respiratory failure. Platelets interact with activated endothelial cells and have been implicated in the pathogenesis of some forms of acute lung injury. Autopsy studies have revealed pulmonary microthrombi after influenza infection, and epidemiological studies suggest that influenza vaccination is protective against pulmonary thromboembolism; however, the effect of influenza infection on platelet-endothelial interactions is unclear. We demonstrate that endothelial infection with both laboratory and clinical strains of influenza virus increased the adhesion of human platelets to primary human lung microvascular endothelial cells. Platelets adhered to infected cells as well as to neighboring cells, suggesting a paracrine effect. Influenza infection caused the upregulation of von Willebrand factor and ICAM-1, but blocking these receptors did not prevent platelet-endothelial adhesion. Instead, platelet adhesion was inhibited by both RGDS peptide and a blocking antibody to platelet integrin α5β1, implicating endothelial fibronectin. Concordantly, lung histology from infected mice revealed viral dose-dependent colocalization of viral nucleoprotein and the endothelial marker PECAM-1, while platelet adhesion and fibronectin deposition also were observed in the lungs of influenza-infected mice. Inhibition of platelets using acetylsalicylic acid significantly improved survival, a finding confirmed using a second antiplatelet agent. Thus, influenza infection induces platelet-lung endothelial adhesion via fibronectin, contributing to mortality from acute lung injury. The inhibition of platelets may constitute a practical adjunctive strategy to the treatment of severe infections with influenza.IMPORTANCE There is growing appreciation of the involvement of the lung endothelium in the pathogenesis of severe infections with influenza virus. We have recently shown that the virus can infect human lung endothelial cells, but the functional consequences of this infection are unknown (S. M. Armstrong, C. Wang, J. Tigdi, X. Si, C. Dumpit, S. Charles, A. Gamage, T. J. Moraes, and W. L. Lee, PLoS One 7:e47323, 2012, http://dx.doi.org/10.1371/journal.pone.0047323). Here, we show that this infection causes platelets to adhere to the lung endothelium. Importantly, blocking platelets using two distinct antiplatelet drugs improved survival in a mouse model of severe influenza infection. Thus, platelet inhibition may constitute a novel therapeutic strategy to improve the host response to severe infections with influenza.
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Olsen KC, Epa AP, Kulkarni AA, Kottmann RM, McCarthy CE, Johnson GV, Thatcher TH, Phipps RP, Sime PJ. Inhibition of transglutaminase 2, a novel target for pulmonary fibrosis, by two small electrophilic molecules. Am J Respir Cell Mol Biol 2014; 50:737-47. [PMID: 24175906 DOI: 10.1165/rcmb.2013-0092oc] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is characterized by progressive fibrotic destruction of normal lung architecture. Due to a lack of effective treatment options, new treatment approaches are needed. We previously identified transglutaminase (TG)2, a multifunctional protein expressed by human lung fibroblasts (HLFs), as a positive driver of fibrosis. TG2 catalyzes crosslinking of extracellular matrix proteins, enhances cell binding to fibronectin and integrin, and promotes fibronectin expression. We investigated whether the small electrophilic molecules 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) and 15-deoxy-delta-12,14-prostaglandin J2 (15d-PGJ2) inhibit the expression and profibrotic functions of TG2. CDDO and 15d-PGJ2 reduced expression of TG2 mRNA and protein in primary HLFs from control donors and donors with IPF. CDDO and 15d-PGJ2 also decreased the in vitro profibrotic effector functions of HLFs including collagen gel contraction and cell migration. The decrease in TG2 expression did not occur through activation of the peroxisome proliferator activated receptor γ or generation of reactive oxidative species. CDDO and 15d-PGJ2 inhibited the extracellular signal-regulated kinase pathway, resulting in the suppression of TG2 expression. This is the first study to show that small electrophilic compounds inhibit the expression and profibrotic effector functions of TG2, a key promoter of fibrosis. These studies identify new and important antifibrotic activities of these two small molecules, which could lead to new treatments for fibrotic lung disease.
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Stoffels JMJ, de Jonge JC, Stancic M, Nomden A, van Strien ME, Ma D, Sisková Z, Maier O, Ffrench-Constant C, Franklin RJM, Hoekstra D, Zhao C, Baron W. Fibronectin aggregation in multiple sclerosis lesions impairs remyelination. ACTA ACUST UNITED AC 2013; 136:116-31. [PMID: 23365094 DOI: 10.1093/brain/aws313] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Remyelination following central nervous system demyelination is essential to prevent axon degeneration. However, remyelination ultimately fails in demyelinating diseases such as multiple sclerosis. This failure of remyelination is likely mediated by many factors, including changes in the extracellular signalling environment. Here, we examined the expression of the extracellular matrix molecule fibronectin on demyelinating injury and how this affects remyelination by oligodendrocytes progenitors. In toxin-induced lesions undergoing efficient remyelination, fibronectin expression was transiently increased within demyelinated areas and declined as remyelination proceeded. Fibronectin levels increased both by leakage from the blood circulation and by production from central nervous system resident cells. In chronically demyelinated multiple sclerosis lesions, fibronectin expression persisted in the form of aggregates, which may render fibronectin resistant to degradation. Aggregation of fibronectin was similarly observed at the relapse phase of chronic experimental autoimmune encephalitis, but not on toxin-induced demyelination, suggesting that fibronectin aggregation is mediated by inflammation-induced demyelination. Indeed, the inflammatory mediator lipopolysaccharide induced fibronectin aggregation by astrocytes. Most intriguingly, injection of astrocyte-derived fibronectin aggregates in toxin-induced demyelinated lesions inhibited oligodendrocyte differentiation and remyelination, and fibronectin aggregates are barely expressed in remyelinated multiple sclerosis lesions. Therefore, these findings suggest that fibronectin aggregates within multiple sclerosis lesions contribute to remyelination failure. Hence, the inhibitory signals induced by fibronectin aggregates or factors that affect fibronectin aggregation could be potential therapeutic targets for promoting remyelination.
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Affiliation(s)
- Josephine M J Stoffels
- Department of Cell Biology, University Medical Centre Groningen, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
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Transglutaminase 2: a molecular Swiss army knife. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:406-19. [PMID: 22015769 DOI: 10.1016/j.bbamcr.2011.09.012] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 09/02/2011] [Accepted: 09/06/2011] [Indexed: 12/26/2022]
Abstract
Transglutaminase 2 (TG2) is the most widely distributed member of the transglutaminase family with almost all cell types in the body expressing TG2 to varying extents. In addition to being widely expressed, TG2 is an extremely versatile protein exhibiting transamidating, protein disulphide isomerase and guanine and adenine nucleotide binding and hydrolyzing activities. TG2 can also act as a protein scaffold or linker. This unique protein also undergoes extreme conformational changes and exhibits localization diversity. Being mainly a cytosolic protein; it is also found in the nucleus, associated with the cell membrane (inner and outer side) and with the mitochondria, and also in the extracellular matrix. These different activities, conformations and localization need to be carefully considered while assessing the role of TG2 in physiological and pathological processes. For example, it is becoming evident that the role of TG2 in cell death processes is dependent upon the cell type, stimuli, subcellular localization and conformational state of the protein. In this review we discuss in depth the conformational and functional diversity of TG2 in the context of its role in numerous cellular processes. In particular, we have highlighted how differential localization, conformation and activities of TG2 may distinctly mediate cell death processes.
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Nicolae C, Olsen BR. Unexpected matrix diseases and novel therapeutic strategies. Cell Tissue Res 2009; 339:155-65. [PMID: 19813027 DOI: 10.1007/s00441-009-0874-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Accepted: 09/02/2009] [Indexed: 01/19/2023]
Abstract
Within the framework of a broad definition of the extracellular matrix (ECM), this review discusses three genetic disorders in which major pathogenetic features have been traced back to alterations in the levels/activities of matrix components. In each case, disease-associated alterations are found both intra- and extracellularly. The nature of the ECM involvement is surprising, offers an exciting therapeutic opportunity, and deepens our understanding of ECM-cell interactions. The first of these disorders, cherubism, is a case of inflammatory bone loss in the jaws of children for reasons that are surprisingly systemic in nature, considering the local nature of the disease. The primary defect involves an intracellular signaling molecule, but a major pathogenetic component and therapeutic target of the disease is the extracellular cytokine tumor necrosis factor alpha. The second disorder, Knobloch syndrome, is caused by recessive mutations in collagen XVIII. Although this protein has been classified as belonging to a group of structural macromolecules, the consequence of the mutations is impairment of cellular metabolism. The third disorder, infantile hemangioma, is a common tumor of capillary endothelial cells in infancy. The tumor appears within a few days/weeks after birth, grows rapidly over several months, and regresses over several years. The proliferative phase is the result of constitutively high levels of vascular endothelial cell growth factor (VEGF)-dependent signaling through VEGF receptor 2 (VEGFR2), but recent studies have led to the surprising conclusion that abnormalities in a cell-surface receptor complex controlling expression of the VEGF decoy receptor VEGFR1 is the underlying cause.
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Affiliation(s)
- Claudia Nicolae
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
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Maeba S, Ichiyama T, Ueno Y, Makata H, Matsubara T, Furukawa S. Effect of montelukast on nuclear factor kappaB activation and proinflammatory molecules. Ann Allergy Asthma Immunol 2005; 94:670-4. [PMID: 15984600 DOI: 10.1016/s1081-1206(10)61326-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Montelukast is known as a cysteinyl leukotriene 1 receptor antagonist. However, the action of montelukast in terms of nuclear factor KB (NF-kappaB) activation and the production of proinflammatory molecules is unknown. OBJECTIVE To demonstrate the potential anti-inflammatory effect of montelukast. METHODS We examined whether montelukast inhibits the activation of NF-kappaB, a transcription factor that regulates the expression of proinflammatory molecules. The inhibitory effects of montelukast on tumor necrosis factor kappa (TNF-kappa)--induced NF-kappaB activation on THP-1 cells, a human monocytic leukemia cell line, were evaluated by flow cytometry, and those on lipopolysaccharide-induced interleukin 1beta (IL-1beta), IL-6, TNF-alpha, and monocyte chemoattractant protein 1 (MCP-1) production in peripheral blood mononuclear cells were evaluated by enzyme-linked immunosorbent assay. RESULTS Flow cytometry demonstrated that montelukast inhibited NF-kappaB activation in THP-1 cells in a dose-related manner. Furthermore, 10(-5)M montelukast significantly inhibited lipopolysaccharide-induced IL-6, TNF-alpha, and MCP-1 production in the peripheral blood mononuclear cells of controls and patients with asthma. Lipopolysaccharide-induced IL-1beta production was not inhibited by montelukast. CONCLUSIONS These findings suggest that high doses of montelukast modulate the production of IL-6, TNF-alpha, and MCP-1 through the inhibition of NF-kappaB activation. However, the anti-inflammatory effect of montelukast at therapeutic doses in patients with asthma needs to be further investigated.
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Affiliation(s)
- Shinji Maeba
- Department of Pediatrics, Yamaguchi University School of Medicine, Yamaguchi, Japan
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Gao B, Saba TM, Tsan MF. Role of alpha(v)beta(3)-integrin in TNF-alpha-induced endothelial cell migration. Am J Physiol Cell Physiol 2002; 283:C1196-205. [PMID: 12225983 DOI: 10.1152/ajpcell.00064.2002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tumor necrosis factor-alpha (TNF-alpha), one of the major inflammatory cytokines, is known to influence endothelial cell migration. In this study, we demonstrate that exposure of calf pulmonary artery endothelial cells to TNF-alpha caused an increase in the formation of membrane protrusions and cell migration. Fluorescence microscopy revealed an increase in alpha(v)beta(3) focal contacts but a decrease in alpha(5)beta(1) focal contacts in TNF-alpha-treated cells. In addition, both cell-surface and total cellular expression of alpha(v)beta(3)-integrins increased significantly, whereas the expression of alpha(5)beta(1)-integrins was unaltered. Only focal contacts containing alpha(v)beta(3)- but not alpha(5)beta(1)-integrins were present in membrane protrusions of cells at the migration front. In contrast, robust focal contacts containing alpha(5)beta(1)-integrins were present in cells behind the migration front. A blocking antibody to alpha(v)beta(3), but not a blocking antibody to alpha(5)-integrins, significantly inhibited TNF-alpha-induced cell migration. These results indicate that in response to TNF-alpha, endothelial cells may increase the activation and ligation of alpha(v)beta(3) while decreasing the activation and ligation of alpha(5)beta(1)-integrins to facilitate cell migration, a process essential for vascular wound healing and angiogenesis.
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MESH Headings
- Animals
- Antibodies, Blocking/pharmacology
- Cattle
- Cell Adhesion/drug effects
- Cell Line
- Cell Movement/drug effects
- Cell Surface Extensions/drug effects
- Cell Surface Extensions/physiology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Focal Adhesions/drug effects
- Focal Adhesions/metabolism
- Focal Adhesions/ultrastructure
- Microscopy, Fluorescence
- Pulmonary Artery
- Receptors, Fibronectin/antagonists & inhibitors
- Receptors, Fibronectin/metabolism
- Receptors, Vitronectin/antagonists & inhibitors
- Receptors, Vitronectin/metabolism
- Tumor Necrosis Factor-alpha/pharmacology
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Affiliation(s)
- Baochong Gao
- Department of Physiology, Albany Medical College, Albany, NY 12208, USA.
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Rotundo RF, Curtis TM, Shah MD, Gao B, Mastrangelo A, LaFlamme SE, Saba TM. TNF-alpha disruption of lung endothelial integrity: reduced integrin mediated adhesion to fibronectin. Am J Physiol Lung Cell Mol Physiol 2002; 282:L316-29. [PMID: 11792637 DOI: 10.1152/ajplung.00145.2000] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tumor necrosis factor-alpha (TNF-alpha) causes an increase in transendothelial protein permeability of confluent monolayers of calf pulmonary artery endothelial (CPAE) cells, and the addition of plasma fibronectin (pFn) to the culture medium can attenuate this increase in permeability. We determined if reduced integrin function had a role in decreased endothelial cell adhesion to immobilized Fn after exposure of the endothelial monolayers to TNF-alpha. TNF-alpha also causes a reorganization of the subendothelial Fn rich matrix and a significant loss in RGD-dependent adhesion of TNF-alpha treated CPAE cells to pFn coated surfaces. However, flow cytometry revealed no decrease in alpha(5)beta(1) or total beta(1) integrin expression on the surface of the CPAE cells after TNF-alpha. Reduced CPAE adhesion to immobilized Fn was, in part, due to a loss of beta(1)-integrin function since the beta(1)-integrin blocking antibody mAb 13 significantly (P < 0.05) prevented the adhesion of normal control CPAE cells but did not further reduce the adhesion of TNF-alpha-treated cells. In addition, antibodies which activate beta(1) integrins restored (P < 0.05) adhesion of TNF-alpha-treated cells to immobilized pFn but did not alter the adhesion of control cells. Despite reduced ability to adhere to immobilized Fn, TNF-alpha-treated CPAE monolayers demonstrated increased binding and incorporation of fluid-phase pFn into the subendothelial extracellular matrix (ECM) as measured by the analysis of the deoxycholate (DOC) detergent insoluble pool of (125)I-Fn in the cell layer. In contrast to the RGD-mediated adhesion of CPAE cells to matrix Fn, the increased binding of soluble pFn after TNF-alpha was not inhibited by RGD peptides or mAb 13. Thus reduced integrin-dependent adhesion of the CPAE cells to matrix Fn as well as disruption of the Fn matrix may contribute to the increased protein permeability of previously confluent endothelial monolayer after TNF-alpha. In addition, increased ability for the monolayer to incorporate fluid-phase Fn into the ECM after TNF-alpha via a non-beta(1)- integrin dependent mechanism may be a compensatory response to stabilize the Fn matrix and the endothelial barrier.
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MESH Headings
- Animals
- Antibodies, Monoclonal/pharmacology
- Antigens, Surface/analysis
- Capillary Permeability/drug effects
- Capillary Permeability/physiology
- Cattle
- Cell Adhesion/drug effects
- Cell Adhesion/physiology
- Cells, Cultured
- Endothelium, Vascular/chemistry
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Epitopes/analysis
- Extracellular Matrix/metabolism
- Fibronectins/metabolism
- Flow Cytometry
- Iodine Radioisotopes
- Manganese/pharmacology
- Microscopy, Interference
- Oligopeptides/metabolism
- Oligopeptides/pharmacology
- Pulmonary Artery/cytology
- Receptors, Fibronectin/analysis
- Receptors, Fibronectin/immunology
- Receptors, Fibronectin/metabolism
- Tumor Necrosis Factor-alpha/metabolism
- Tumor Necrosis Factor-alpha/pharmacology
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Affiliation(s)
- Robert F Rotundo
- Department of Physiology and Cell Biology, Neil Hellman Medical Research Building, Albany Medical College, Albany, New York 12208, USA
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