Immunotargeting of glucose oxidase to endothelium in vivo causes oxidative vascular injury in the lungs

2000 ◽  
Vol 278 (4) ◽  
pp. L794-L805 ◽  
Author(s):  
Melpo Christofidou-Solomidou ◽  
Giuseppe G. Pietra ◽  
Charalambos C. Solomides ◽  
Evgenia Arguiris ◽  
David Harshaw ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Lung Injury ◽  
Glucose Oxidase ◽  
Intravenous Injection ◽  
Vascular Injury ◽  
Target Cells ◽  
Pulmonary Endothelium ◽  
Endothelial Cell Surface ◽  
Novel Approach

Vascular immunotargeting is a novel approach for site-selective drug delivery to endothelium. To validate the strategy, we conjugated glucose oxidase (GOX) via streptavidin with antibodies to the endothelial cell surface antigen platelet endothelial cell adhesion molecule (PECAM). Previous work documented that 1) anti-PECAM-streptavidin carrier accumulates in the lungs after intravenous injection in animals and 2) anti-PECAM-GOX binds to, enters, and kills endothelium via intracellular H2O2 generation in cell culture. In the present work, we studied the targeting and effect of anti-PECAM-GOX in animals. Anti-PECAM-GOX, but not IgG-GOX, accumulated in the isolated rat lungs, produced H2O2, and caused endothelial injury manifested by a fourfold elevation of angiotensin-converting enzyme activity in the perfusate. In intact mice, anti-PECAM-GOX accumulated in the lungs (27 ± 9 vs. 2.4 ± 0.3% injected dose/g for IgG-GOX) and caused severe lung injury and 95% lethality within hours after intravenous injection. Endothelial disruption and blebbing, elevated lung wet-to-dry ratio, and interstitial and alveolar edema indicated that anti-PECAM-GOX damaged pulmonary endothelium. The vascular injury in the lungs was associated with positive immunostaining for iPF2α-III isoprostane, a marker for oxidative stress. In contrast, IgG-GOX caused a minor lung injury and little (5%) lethality. Anti-PECAM conjugated with inert proteins induced no death or lung injury. None of the conjugates caused major injury to other internal organs. These results indicate that an immunotargeting strategy can deliver an active enzyme to selected target cells in intact animals. Anti-PECAM-GOX provides a novel model of oxidative injury to the pulmonary endothelium in vivo.

PECAM-directed delivery of catalase to endothelium protects against pulmonary vascular oxidative stress

2003 ◽  
Vol 285 (2) ◽  
pp. L283-L292 ◽  
Author(s):  
Melpo Christofidou-Solomidou ◽  
Arnaud Scherpereel ◽  
Rainer Wiewrodt ◽  
Kimmie Ng ◽  
Thomas Sweitzer ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lung Injury ◽  
Intravenous Injection ◽  
Targeted Delivery ◽  
Ischemia Reperfusion ◽  
Therapeutic Interventions ◽  
Protective Effects ◽  
Stress Injury ◽  
Pulmonary Endothelium

Targeted delivery of drugs to vascular endothelium promises more effective and specific therapies in many disease conditions, including acute lung injury (ALI). This study evaluates the therapeutic effect of drug targeting to PECAM (platelet/endothelial cell adhesion molecule-1) in vivo in the context of pulmonary oxidative stress. Endothelial injury by reactive oxygen species (e.g., H2O2) is involved in many disease conditions, including ALI/acute respiratory distress syndrome and ischemia-reperfusion. To optimize delivery of antioxidant therapeutics, we conjugated catalase with PECAM antibodies and tested properties of anti-PECAM/catalase conjugates in cell culture and mice. Anti-PECAM/catalase, but not an IgG/catalase counterpart, bound specifically to PECAM-expressing cells, augmented their H2O2-degrading capacity, and protected them against H2O2 toxicity. Anti-PECAM/catalase, but not IgG/catalase, rapidly accumulated in the lungs after intravenous injection in mice, where it was confined to the pulmonary endothelium. To test its protective effect, we employed a murine model of oxidative lung injury induced by glucose oxidase coupled with thrombomodulin antibody (anti-TM/GOX). After intravenous injection in mice, anti-TM/GOX binds to pulmonary endothelium and produces H2O2, which causes lung injury and 100% lethality within 7 h. Coinjection of anti-PECAM/catalase protected against anti-TM/GOX-induced pulmonary oxidative stress, injury, and lethality, whereas polyethylene glycol catalase or IgG/catalase conjugates afforded only marginal protective effects. This result validates vascular immunotargeting as a prospective strategy for therapeutic interventions aimed at immediate protective effects, e.g., for augmentation of antioxidant defense in the pulmonary endothelium and treatment of ALI.

scholarly journals Surface charge distribution on the endothelial cell of liver sinusoids.

1984 ◽  
Vol 99 (2) ◽  
pp. 639-647 ◽  
Author(s):  
L Ghitescu ◽  
A Fixman
Keyword(s):  
Endothelial Cell ◽  
Cell Surface ◽  
Liver Sinusoid ◽  
Electron Microscopic ◽  
Coated Pits ◽  
Endothelial Cell Surface ◽  
Liver Sinusoids ◽  
Surface Charge Distribution ◽  
Cationic Residues

The topography of the charged residues on the endothelial cell surface of liver sinusoid capillaries was investigated by using electron microscopic tracers of different size and charge. The tracers used were native ferritin (pl 4.2-4.7) and its cationized (pl 8.4) and anionized (pl 3.7) derivatives, BSA coupled to colloidal gold (pl of the complex 5.1), hemeundecapeptide (pl 4.85), and alcian blue (pl greater than 10). The tracers were either injected in vivo or perfused in situ through the portal vein of the mouse liver. In some experiments, two tracers of opposite charge were sequentially perfused with extensive washing in between. The liver was processed for electron microscopy and the binding pattern of the injected markers was recorded. The electrostatic nature of the tracer binding was assessed by perfusion with high ionic strength solutions, by aldehyde quenching of the plasma membrane basic residues, and by substituting the cell surface acidic moieties with positively charged groups. Results indicate that the endothelial cells of the liver sinusoids expose on their surface both cationic and anionic residues. The density distribution of these charged groups on the cell surface is different. While the negative charge is randomly and patchily scattered all over the membrane, the cationic residues seem to be accumulated in coated pits. The charged groups co-exist in the same coated pit and bind the opposite charged macromolecule. It appears that the fixed positive and negative charges of the coated pit glycocalyx are mainly segregated in space. The layer of basic residues is located at 20-30-nm distance of the membrane, while most of the negative charges lie close to the external leaflet of the plasmalemma.

Abstract 13667: Programming to S1PR1 + Endothelial Cell Population Promotes the Restoration of Vascular Integrity in vivo

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Zahid Akhter ◽  
Jagdish Chandra Joshi ◽  
Vijay Avin Balaji Ragunathrao ◽  
Richard L Proia ◽  
Asrar B Malik ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Lung Injury ◽  
Endothelial Permeability ◽  
Vascular Diseases ◽  
Mechanistic Study ◽  
Rna Seq ◽  
Vascular Integrity ◽  
Injured Lung ◽  
Sphingosine 1 Phosphate

Introduction: Increased endothelial permeability and failure to repair is the hallmark of several vascular diseases including acute lung injury (ALI). However, little is known about the intrinsic pathways that activate the endothelial cell (EC) regenerative programs facilitating thereby tissue repair. Studies have invoked a crucial role of sphingosine-1-phosphate (S1P) in resolving endothelial hyperpermeability through activation of the G-protein coupled receptor, sphingosine-1-phosphate receptor 1 (S1PR1). Hypothesis: We postulate that S1PR1 + EC serve as an endogenous means to prevent endothelial injury. Methods: Studies were made using EC-S1PR1 null mice and S1PR1-GFP reporter mice to trace the generation and characteristics of S1PR1 + EC by exploiting immuno-histochemical analysis and FACS. RNA-seq analysis was performed to identify the genetic signature of S1PR1 + EC. Combination of genetic and pharmacological strategies were included for mechanistic study. Transplantation of S1PR1 + EC and edema measurement was performed in EC-S1PR1 null mice. Results: We observed in a mouse model of endotoxemia that LPS via generation of S1P induced the programming of S1PR1 lo EC to S1PR1 + EC, comprising 80% of lung EC. Their generation preceded the vascular repair phase and these cells were required for reestablishing the endothelial barrier function. Thus, conditional deletion of S1PR1 in EC spontaneously increased lung vascular permeability. RNA-seq analysis of S1PR1 + EC showed enrichment of genes regulating S1P synthesis and transport, sphingosine kinase 1 (SPHK1) and SPNS2, respectively, as well as transcription factors EGR1 and STAT3. EGR1 and STAT3 were essential for transcribing SPHK1 and SPNS2, respectively to increase S1P concentration that served to amplify S1PR1 + EC transition. Transplantation of S1PR1 + EC into injured lung vasculature of EC-S1PR1 -/- mice restored endothelial integrity. Conclusions: Findings illustrate that generation of a specialized S1PR1 + EC population has the potential to activate key endothelial regenerative program mediating vascular endothelial repair raising the possibility of activating this pathway to restore vascular homeostasis in inflammatory lung injury.

scholarly journals Bovine Organospecific Microvascular Endothelial Cell Lines as New and Relevant In Vitro Models to Study Viral Infections

2020 ◽  
Vol 21 (15) ◽  
pp. 5249 ◽  
Author(s):  
Anne-Claire Lagrée ◽  
Fabienne Fasani ◽  
Clotilde Rouxel ◽  
Marine Pivet ◽  
Marie Pourcelot ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Lines ◽  
T Antigen ◽  
In Vitro Studies ◽  
Microvascular Endothelial Cell ◽  
Target Cells ◽  
Microvascular Endothelial

Microvascular endothelial cells constitute potential targets for exogenous microorganisms, in particular for vector-borne pathogens. Their phenotypic and functional variations according to the organs they are coming from provide an explanation of the organ selectivity expressed in vivo by pathogens. In order to make available relevant tools for in vitro studies of infection mechanisms, our aim was to immortalize bovine organospecific endothelial cells but also to assess their permissivity to viral infection. Using transfection with SV40 large T antigen, six bovine microvascular endothelial cell lines from various organs and one macrovascular cell line from an umbilical cord were established. They display their own panel of endothelial progenitor/mature markers, as assessed by flow cytometry and RT-qPCR, as well as the typical angiogenesis capacity. Using both Bluetongue and foot-and-mouth disease viruses, we demonstrate that some cell lines are preferentially infected. In addition, they can be transfected and are able to express viral proteins such as BTV8-NS3. Such microvascular endothelial cell lines bring innovative tools for in vitro studies of infection by viruses or bacteria, allowing for the study of host-pathogen interaction mechanisms with the actual in vivo target cells. They are also suitable for applications linked to microvascularization, such as anti-angiogenic and anti-tumor research, growing fields in veterinary medicine.

The expression of endothelial tissue plasminogen activator in vivo: a function defined by vessel size and anatomic location

1997 ◽  
Vol 110 (2) ◽  
pp. 139-148
Author(s):  
E.G. Levin ◽  
L. Santell ◽  
K.G. Osborn
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Plasminogen Activator ◽  
Lung Tissue ◽  
Vascular System ◽  
Vessel Size ◽  
Pulmonary Vessels ◽  
Pulmonary Endothelium ◽  
Tissue Plasminogen

Plasma tissue plasminogen activator (tPA) has long been considered to be the product of the endothelial cells that line the various parts of the vascular system regardless of vessel size or location. To determine whether this was truly the case in vivo, the distribution of tPA in the endothelium of the mouse lung and other tissues was evaluated. Immunohistochemical analysis of normal lung tissue showed positive staining limited to the endothelial cells of the bronchial arteries regardless of size with few cells of the pulmonary circulation associated with tPA. The pulmonary vessels that did contain endothelial cell-derived tPA were consistently between 7 and 30 microns in diameter. No capillary or large vessel pulmonary endothelium ever stained positive. These results were also observed in primate lung tissue where the bronchial endothelium of all vessels, even down to capillary size, contained tPA while none of the pulmonary endothelium did. Prolonged exposure of mice to hyperoxic conditions promotes acute lung injury and associated inflammation. Using this model, the effect of inflammation on endothelial cell tPA expression was evaluated. A 4.5-fold increase in the number of pulmonary vessels staining positive for tPA was observed after 66 hours with all of these vessels having a diameter between 7 and 30 microns. Again, none of the endothelium of large arteries or veins nor the capillaries had tPA. Whole tissue tPA mRNA increased dramatically with hyperoxia and in situ hybridization analysis showed tPA mRNA in the endothelium of the same types of vessels as antigen. The tPA localized to both the bronchial and pulmonary endothelium was active with neither tPA-PAI-1 complexes nor urokinase found in perfused lung tissue. These results indicate that endothelial cell tPA expression, either constitutive or induced by a pathologic event, is a function of a highly select group of endothelial cells which are defined by their association with vessels of discrete size and/or anatomic location. Thus, the widely held concept that the steady state level of plasma tPA is maintained through its constitutive production by all endothelial cells of the vascular system is invalid. Also suggested is the possibility that endothelial cell tPA might play a broader role than simply maintaining vessel patency as a component of the fibrinolytic pathway and contribute to complex dynamic processes such as inflammation.

scholarly journals GRP78 is a novel receptor initiating a vascular barrier protective response to oxidized phospholipids

2014 ◽  
Vol 25 (13) ◽  
pp. 2006-2016 ◽  
Author(s):  
Anna A. Birukova ◽  
Patrick A. Singleton ◽  
Grzegorz Gawlak ◽  
Xinyong Tian ◽  
Tamara Mirzapoiazova ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Endothelial Cell ◽  
Lung Injury ◽  
Ischemia Reperfusion ◽  
Cell Junctions ◽  
Endothelial Barrier ◽  
Oxidized Phospholipids ◽  
Vascular Integrity

Vascular integrity and the maintenance of blood vessel continuity are fundamental features of the circulatory system maintained through endothelial cell–cell junctions. Defects in the endothelial barrier become an initiating factor in several pathologies, including ischemia/reperfusion, tumor angiogenesis, pulmonary edema, sepsis, and acute lung injury. Better understanding of mechanisms stimulating endothelial barrier enhancement may provide novel therapeutic strategies. We previously reported that oxidized phospholipids (oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine [OxPAPC]) promote endothelial cell (EC) barrier enhancement both in vitro and in vivo. This study examines the initiating mechanistic events triggered by OxPAPC to increase vascular integrity. Our data demonstrate that OxPAPC directly binds the cell membrane–localized chaperone protein, GRP78, associated with its cofactor, HTJ-1. OxPAPC binding to plasma membrane–localized GRP78 leads to GRP78 trafficking to caveolin-enriched microdomains (CEMs) on the cell surface and consequent activation of sphingosine 1-phosphate receptor 1, Src and Fyn tyrosine kinases, and Rac1 GTPase, processes essential for cytoskeletal reorganization and EC barrier enhancement. Using animal models of acute lung injury with vascular hyperpermeability, we observed that HTJ-1 knockdown blocked OxPAPC protection from interleukin-6 and ventilator-induced lung injury. Our data indicate for the first time an essential role of GRP78 and HTJ-1 in OxPAPC-mediated CEM dynamics and enhancement of vascular integrity.

Ventilator-induced lung injury: in vivo and in vitro mechanisms

2002 ◽  
Vol 283 (4) ◽  
pp. L678-L682 ◽  
Author(s):  
Michael A. Matthay ◽  
Sunita Bhattacharya ◽  
Donald Gaver ◽  
Lorraine B. Ware ◽  
Lina H. K. Lim ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Barrier Properties ◽  
Pulmonary Endothelium ◽  
Ventilator Induced Lung Injury ◽  
Proinflammatory Responses ◽  
Substantial Progress ◽  
Made In

A lung-protective ventilator strategy significantly reduces mortality in patients with acute lung injury. Substantial progress has been made in understanding how mechanical stress can injure the lung, both in terms of alterations in barrier properties of the pulmonary endothelium and epithelium as well as in stimulating proinflammatory responses of macrophages and neutrophils.

scholarly journals Autophagy inhibitor 3-methyladenine protects against endothelial cell barrier dysfunction in acute lung injury

2018 ◽  
Vol 314 (3) ◽  
pp. L388-L396 ◽  
Author(s):  
Spencer A. Slavin ◽  
Antony Leonard ◽  
Valerie Grose ◽  
Fabeha Fazal ◽  
Arshad Rahman
Keyword(s):  
Acute Lung Injury ◽  
Endothelial Cell ◽  
Lung Injury ◽  
Vascular Injury ◽  
Barrier Dysfunction ◽  
Neutrophil Sequestration ◽  
Barrier Disruption ◽  
Proinflammatory Mediators ◽  
Autophagy Inhibitor

Autophagy is an evolutionarily conserved cellular process that facilitates the continuous recycling of intracellular components (organelles and proteins) and provides an alternative source of energy when nutrients are scarce. Recent studies have implicated autophagy in many disorders, including pulmonary diseases. However, the role of autophagy in endothelial cell (EC) barrier dysfunction and its relevance in the context of acute lung injury (ALI) remain uncertain. Here, we provide evidence that autophagy is a critical component of EC barrier disruption in ALI. Using an aerosolized bacterial lipopolysaccharide (LPS) inhalation mouse model of ALI, we found that administration of the autophagy inhibitor 3-methyladenine (3-MA), either prophylactically or therapeutically, markedly reduced lung vascular leakage and tissue edema. 3-MA was also effective in reducing the levels of proinflammatory mediators and lung neutrophil sequestration induced by LPS. To test the possibility that autophagy in EC could contribute to lung vascular injury, we addressed its role in the mechanism of EC barrier disruption. Knockdown of ATG5, an essential regulator of autophagy, attenuated thrombin-induced EC barrier disruption, confirming the involvement of autophagy in the response. Similarly, exposure of cells to 3-MA, either before or after thrombin, protected against EC barrier dysfunction by inhibiting the cleavage and loss of vascular endothelial cadherin at adherens junctions, as well as formation of actin stress fibers. 3-MA also reversed LPS-induced EC barrier disruption. Together, these data imply a role of autophagy in lung vascular injury and reveal the protective and therapeutic utility of 3-MA against ALI.

scholarly journals A Spread-Deficient Cytomegalovirus for Assessment of First-Target Cells in Vaccination

2010 ◽  
Vol 84 (15) ◽  
pp. 7730-7742 ◽  
Author(s):  
Christian Andreas Mohr ◽  
Jurica Arapovic ◽  
Hermine Mühlbach ◽  
Marc Panzer ◽  
Annelies Weyn ◽  
...  
Keyword(s):  
Essential Gene ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
T Cell Response ◽  
Target Cells ◽  
Wild Type ◽  
Genome Maintenance ◽  
Novel Approach ◽  
Protective Strategy

ABSTRACT Human cytomegalovirus (HCMV) is a human pathogen that causes severe disease primarily in the immunocompromised or immunologically immature individual. To date, no vaccine is available. We describe use of a spread-deficient murine CMV (MCMV) as a novel approach for betaherpesvirus vaccination. To generate a spread-deficient MCMV, the conserved, essential gene M94 was deleted. Immunization with MCMV-ΔM94 is apathogenic and protective against wild-type challenge even in highly susceptible IFNαβR−/− mice. MCMV-ΔM94 was able to induce a robust CD4+ and CD8+ T-cell response as well as a neutralizing antibody response comparable to that induced by wild-type infection. Endothelial cells were identified as activators of CD8+ T cells in vivo. Thus, the vaccination with a spread-deficient betaherpesvirus is a safe and protective strategy and allows the linkage between cell tropism and immunogenicity. Furthermore, genomes of MCMV-ΔM94 were present in lungs 12 months after infection, revealing first-target cells as sites of genome maintenance.

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