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Ong E, Gao XP, Predescu D, Broman M, Malik AB. Role of phosphatidylinositol 3-kinase-gamma in mediating lung neutrophil sequestration and vascular injury induced by E. coli sepsis. Am J Physiol Lung Cell Mol Physiol 2005; 289:L1094-103. [PMID: 16183669 DOI: 10.1152/ajplung.00179.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We addressed the in vivo role of phosphatidylinositol 3-kinase-gamma (PI3K-gamma) in signaling the sequestration of polymorphonuclear leukocytes (PMNs) in lungs and in the mechanism of inflammatory lung vascular injury. We studied mice with deletion of the p110 catalytic subunit of PI3K-gamma (PI3K-gamma(-/-) mice). We measured lung tissue PMN sequestration, microvascular permeability, and edema formation after bacteremia induced by intraperitoneal Escherichia coli challenge. PMN infiltration into the lung interstitium in PI3K-gamma(-/-) mice as assessed morphometrically was increased 100% over that in control mice within 1 h after bacterial challenge. PI3K-gamma(-/-) mice also developed a greater increase in lung microvascular permeability after E. coli challenge, resulting in edema formation. The augmented lung tissue PMN sequestration in PI3K-gamma(-/-) mice was associated with increased expression of the PMN adhesive proteins CD47 and beta(3)-integrins. We observed increased association of CD47 and beta(3)-integrins with the extracellular matrix protein vitronectin in lungs of PI3K-gamma(-/-) mice after E. coli challenge. PMNs from these mice also showed increased beta(3)-integrin expression and augmented beta(3)-integrin-dependent PMN adhesion to vitronectin. These results point to a key role of PMN PI3K-gamma in negatively regulating CD47 and beta(3)-integrin expression in gram-negative sepsis. PI3K-gamma activation in PMNs induced by E. coli may modulate the extent of lung tissue PMN sequestration secondary to CD47 and beta(3)-integrin expression. Therefore, the level of PI3K-gamma activation may be an important determinant of PMN-dependent lung vascular injury.
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Affiliation(s)
- Evan Ong
- Dept. of Pharmacology, College of Medicine, The University of Illinois, 835 South Wolcott Avenue, Chicago, IL 60612-7343, USA
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202
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Macias WL, Yan SB, Williams MD, Um SL, Sandusky GE, Ballard DW, Planquois JMS. New insights into the protein C pathway: potential implications for the biological activities of drotrecogin alfa (activated). CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2005; 9 Suppl 4:S38-45. [PMID: 16168074 PMCID: PMC3226161 DOI: 10.1186/cc3747] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
It has been hypothesized that the protein C pathway is a pivotal link between the inflammation and coagulation cascades. The demonstration that a survival benefit is associated with administration of drotrecogin alfa (activated) (recombinant human activated protein C [APC]) in severe sepsis patients has provided new insights into the protein C pathway. APC was originally identified based on its antithrombotic properties, which result from the inhibition of activated Factors V and VIII. In the early 1990s, any potential anti-inflammatory properties of APC were thought to relate primarily to its inhibition of thrombin generation. However, the mid-1990s saw the identification of the endothelial protein C receptor (EPCR), which has subsequently been shown to be neither endothelial specific nor protein C specific, but has a primary function as a cofactor for enhancing the generation of APC or behaving as an APC receptor. Thus, the potential biologic activities of APC can be classed into two categories related either to the limiting of thrombin generation or to cellular effects initiated by binding to the EPCR. Intracellular signaling initiated by binding of APC to its receptor appears to be mediated by interaction with an adjacent protease-activated receptor (PAR), or by indirect activation of the sphingosine 1-phosphate pathway. Based mostly on in vitro studies, binding of APC to its receptor on endothelial cells leads to a decrease in thrombin-induced endothelial permeability injury, while such binding on blood cells, epithelial cells, and neurons has been shown to inhibit chemotaxis, be anti-apoptotic, and be neuroprotective, respectively. In the Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis (PROWESS) study, drotrecogin alfa (activated) was associated with improved cardiovascular function, respiratory function, and a prevention of hematologic dysfunction. This article discusses the way in which the interactions of APC may alter the microcirculation.
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Affiliation(s)
| | - S Betty Yan
- Lilly Research Laboratories, Indianapolis, Indiana, USA
| | | | - Suzane L Um
- Lilly Research Laboratories, Indianapolis, Indiana, USA
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203
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Yiming MT, Parthasarathi K, Issekutz AC, Bhattacharya S. Sequence of endothelial signaling during lung expansion. Am J Respir Cell Mol Biol 2005; 33:549-54. [PMID: 16123392 PMCID: PMC2715332 DOI: 10.1165/rcmb.2005-0133oc] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Although high tidal volume ventilation exacerbates lung injury, the mechanisms underlying the inflammatory response are not clear. Here, we exposed isolated lungs to high or low tidal volume ventilation, while perfusing lungs with whole blood, or blood depleted of leukocytes and platelets. Then, we determined signaling responses in freshly isolated lung endothelial cells by means of immunoblotting and immunofluorescence approaches. In depleted blood perfusion, high tidal volume induced modest increases in both P-selectin expression on the endothelial surface, and in endothelial protein tyrosine phosphorylation. Both high tidal volume-induced responses were markedly enhanced in the presence of whole blood perfusion. However, a P-selectin-blocking antibody given together with whole blood perfusion inhibited the responses down to levels corresponding to those for depleted blood perfusion. These findings indicate that the full proinflammatory response occurs in two stages. First, lung distension causes modest endothelial activation. Second, subsequent endothelial-inflammatory cell interactions augment P-selectin expression and tyrosine phosphorylation. We conclude that interactions of circulating inflammatory cells with P-selectin critically determine proinflammatory endothelial activation during high tidal volume ventilation.
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Affiliation(s)
- Maimaiti T Yiming
- St. Luke's-Roosevelt Hospital Center, AJA #510, 1000 10th Avenue, New York, NY 10019, USA
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204
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Garbacki N, Kinet M, Nusgens B, Desmecht D, Damas J. Proanthocyanidins, from Ribes nigrum leaves, reduce endothelial adhesion molecules ICAM-1 and VCAM-1. JOURNAL OF INFLAMMATION-LONDON 2005; 2:9. [PMID: 16091140 PMCID: PMC1198248 DOI: 10.1186/1476-9255-2-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Accepted: 08/09/2005] [Indexed: 11/10/2022]
Abstract
BACKGROUND The effects of proanthocyanidins (PACs), isolated from blackcurrant (Ribes nigrum L.) leaves, on neutrophil accumulation during inflammatory processes were investigated in vivo and in vitro. METHODS In vivo studies were performed using carrageenin-induced pleurisy in rats pre-treated with PACs. Exudate volume and PMNs accumulation were measured. Leukocyte cell adhesion molecules (LFA-1, Mac-1 and VLA-4) mobilization in circulating granulocytes were analysed by flow cytometry and endothelial cell adhesion molecules (ICAM-1 and VCAM-1) were detected by immunohistochemistry on lung sections. In vitro studies were conducted on endothelial LT2 cells, stimulated with TNF-alpha, to evaluate ICAM-1, IL-8 and VEGF mRNA expression upon PACs treatment. Data sets were examined by one-way analysis of variance (ANOVA) followed by a Scheffe post-hoc test. RESULTS Pretreatment of the animals with PACs (10, 30 and 60 mg/kg) inhibited dose-dependently carrageenin-induced pleurisy in rats by reducing pleural exudate formation and PMNs infliltration. Leukocyte cell adhesion molecules mobilization was not down-regulated on granulocytes by PACs. Immunohistochemistry on lung sections showed a decreased production of endothelial cell adhesion molecules. In vitro experiments demonstrated that PACs were able to significantly inhibit ICAM-1 but not IL-8 and VEGF165 mRNA expression. Moreover, VEGF121 mRNA expression was dose-dependently enhanced. CONCLUSION This study provides evidence to support the anti-inflammatory activity of proanthocyanidins is related to an inhibition of leukocyte infiltration which can be explained at least in part by a down-regulation of endothelial adhesion molecules, ICAM-1 and VCAM-1 and that these compounds are capable of modulating TNF-alpha-induced VEGF transcription.
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Affiliation(s)
- N Garbacki
- Laboratoire de Physiologie humaine, CHU, Tour 3, Université de Liège, Avenue de l'Hôpital, 3, B-4000 Sart Tilman, Belgium
| | - M Kinet
- Laboratoire de Physiologie humaine, CHU, Tour 3, Université de Liège, Avenue de l'Hôpital, 3, B-4000 Sart Tilman, Belgium
| | - B Nusgens
- Laboratoire de Biologie des Tissus Conjonctifs, Tour 3, Université de Liège, Avenue de l'Hôpital, 3, B-4000 Sart Tilman, Belgium
| | - D Desmecht
- Département de Morphologie et de Pathologie, Pathologie générale, Faculté de Médecine vétérinaire, Université de Liège, bvd de Colonster, 20, B-4000 Sart Tilman, Belgium
| | - J Damas
- Laboratoire de Physiologie humaine, CHU, Tour 3, Université de Liège, Avenue de l'Hôpital, 3, B-4000 Sart Tilman, Belgium
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205
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Kuang PP, Lucey E, Rishikof DC, Humphries DE, Bronsnick D, Goldstein RH. Engraftment of neonatal lung fibroblasts into the normal and elastase-injured lung. Am J Respir Cell Mol Biol 2005; 33:371-7. [PMID: 16037486 PMCID: PMC2715345 DOI: 10.1165/rcmb.2004-0319oc] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Interstitial fibroblasts are an integral component of the alveolar wall. These cells produce matrix proteins that maintain the extracellular scaffold of alveolar structures. Emphysema is characterized by airspace enlargement resulting from the loss of alveolar cellularity and matrix. In this study, we explored the endotracheal delivery of fibroblasts to the lung parenchyma as a means of repairing damaged alveolar structures directly or indirectly for the delivery of transgenes. Fibroblasts were isolated from the lungs of neonatal transgenic mice expressing GFP during the period of rapid alveolarization. These GFP+ cells maintained their myofibroblast phenotype in culture and expressed elastin and alpha-smooth muscle actin mRNA. We administered GFP+ fibroblasts to saline- and elastase-treated mice by endotracheal instillation. We detected more GFP+ fibroblasts in the alveolar walls and in the interstitial areas of elastase-injured lungs than in normal lungs as assessed by immunohistochemistry and fluorescent imaging. The presence of GFP+ fibroblasts in the interstitium demonstrated transepithelial migration of these cells. Expression of GFP+ fibroblasts in recipient lungs was maintained for at least 20 d after endotracheal administration. These cells synthesize matrix components including elastin in vitro and could contribute to restoring the structural integrity of the alveolar wall.
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Affiliation(s)
- Ping-Ping Kuang
- The Pulmonary Center, Boston University School of Medicine, Boston, MA 02118, USA
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206
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Reutershan J, Basit A, Galkina EV, Ley K. Sequential recruitment of neutrophils into lung and bronchoalveolar lavage fluid in LPS-induced acute lung injury. Am J Physiol Lung Cell Mol Physiol 2005; 289:L807-15. [PMID: 15951336 DOI: 10.1152/ajplung.00477.2004] [Citation(s) in RCA: 244] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Infiltration of activated neutrophils [polymorphonuclear leukocytes (PMN)] into the lung is an important component of the inflammatory response in acute lung injury. The signals required to direct PMN into the different compartments of the lung have not been fully elucidated. In a murine model of LPS-induced lung injury, we investigated the sequential recruitment of PMN into the pulmonary vasculature, lung interstitium, and alveolar space. Mice were exposed to aerosolized LPS and bronchoalveolar lavage fluid (BAL), and lungs were harvested at different time points. We developed a flow cytometry-based technique to assess in vivo trafficking of PMN in the intravascular and extravascular lung compartments. Aerosolized LPS induced consistent PMN migration into all lung compartments. We found that sequestration in the pulmonary vasculature occurred within the first hour. Transendothelial migration into the interstitial space started 1 h after LPS exposure and increased continuously until a plateau was reached between 12 and 24 h. Transepithelial migration into the alveolar air space was delayed, as the first PMN did not appear until 2 h after LPS, reaching a peak at 24 h. Transendothelial migration and transepithelial migration were inhibited by pertussis toxin, indicating involvement of Galphai-coupled receptors. These findings confirm LPS-induced migration of PMN into the lung. For the first time, distinct transmigration steps into the different lung compartments are characterized in vivo.
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Affiliation(s)
- Jörg Reutershan
- Robert M. Berne Cardiovascular Research Center, Department of Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
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207
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Ichimura H, Parthasarathi K, Issekutz AC, Bhattacharya J. Pressure-induced leukocyte margination in lung postcapillary venules. Am J Physiol Lung Cell Mol Physiol 2005; 289:L407-12. [PMID: 15879460 DOI: 10.1152/ajplung.00048.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although pressure elevation in lung postcapillary venules increases endothelial P-selectin expression, the extent to which P-selectin causes lung leukocyte margination remains controversial. To address this issue, we optically viewed postcapillary venules of the isolated blood-perfused rat lung by real-time fluorescence imaging. To determine leukocyte margination in single postcapillary venules, we quantified the fluorescence of leukocytes labeled in situ with rhodamine 6G (R6G). Although baseline fluorescence was sparse, a 10-min pressure elevation by 10 cmH(2)O markedly increased R6G fluorescence. Both stopping blood flow during pressure elevation and eliminating leukocytes from the perfusion blocked the fluorescence increase, affirming that these fluorescence responses were attributable to pressure-induced leukocyte margination. A P-selectin-blocking MAb and the L- and P-selectin blocker fucoidin each inhibited the fluorescence increase, indicating that P-selectin was critical for inducing margination. Time-dependent imaging of blood-borne fluorescent beads revealed reduction of plasma velocity during pressure elevation. After pressure returned to baseline, a similar reduction of plasma velocity, established by manually decreasing the perfusion rate, prolonged margination. Our findings show that in lung postcapillary venules, the decrease in plasma velocity critically determines pressure-induced leukocyte margination.
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Affiliation(s)
- Hideo Ichimura
- lung Biology Laboratory, Department of Physiology and Cellular Biophysics, Columbia University, New York, New York, USA
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208
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Yang L, Froio RM, Sciuto TE, Dvorak AM, Alon R, Luscinskas FW. ICAM-1 regulates neutrophil adhesion and transcellular migration of TNF-alpha-activated vascular endothelium under flow. Blood 2005; 106:584-92. [PMID: 15811956 PMCID: PMC1635241 DOI: 10.1182/blood-2004-12-4942] [Citation(s) in RCA: 538] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In vivo, leukocyte transendothelial migration (TEM) occurs at endothelial cell junctions (paracellular) and nonjunctional (transcellular) locations, whereas in vitro models report that TEM is mostly paracellular. The mechanisms that control the route of leukocyte TEM remain unknown. Here we tested the hypothesis that elevated intercellular adhesion molecule-1 (ICAM-1) expression regulates the location of polymorphonuclear leukocyte (PMN) TEM. We used an in vitro flow model of tumor necrosis factor-alpha (TNF-alpha)-activated human umbilical vein endothelium cells (HUVECs) or an HUVEC cell line transfected with ICAM-1GFP (green fluorescent protein) and live-cell fluorescence microscopy to quantify the location of PMN adhesion and TEM. We observed robust transcellular TEM with TNF-alpha-activated HUVECs and ICAM-1GFP immortalized HUVECS (iHUVECs). In contrast, primary CD3+ T lymphocytes exclusively used a paracellular route. Endothelial ICAM-1 was identified as essential for both paracellular and transcellular PMN transmigration, and interfering with ICAM-1 cytoplasmic tail function preferentially reduced transcellular TEM. We also found that ICAM-1 surface density and distribution as well as endothelial cell shape contributed to transcellular TEM. In summary, ICAM-1 promotes junctional and nonjunctional TEM across inflamed vascular endothelium via distinct cytoplasmic tail associations.
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Affiliation(s)
- Lin Yang
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, NRB 752P, Boston, MA 02215, USA
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209
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Abstract
Because the lungs function as the body's gas-exchange organ, they are inevitably exposed to air that is contaminated with pathogens, allergens and pollutants. Host-defence mechanisms within the lungs must facilitate clearance of inhaled pathogens and particles while minimizing an inflammatory response that could damage the thin, delicate gas-exchanging epithelium. Pulmonary surfactant is a complex of lipids and proteins that enhances pathogen clearance and regulates adaptive and innate immune-cell functions. In this article, I review the structure and functions of the surfactant proteins SP-A and SP-D in regulating host immune defence and in modulating inflammatory responses.
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Affiliation(s)
- Jo Rae Wright
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710, USA.
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210
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Ganiko L, Martins AR, Freymüller E, Mortara RA, Roque-Barreira MC. Lectin KM+-induced neutrophil haptotaxis involves binding to laminin. Biochim Biophys Acta Gen Subj 2005; 1721:152-63. [PMID: 15652190 DOI: 10.1016/j.bbagen.2004.10.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Revised: 09/29/2004] [Accepted: 10/20/2004] [Indexed: 01/13/2023]
Abstract
The lectin KM+ from Artocarpus integrifolia, also known as artocarpin, induces neutrophil migration by haptotaxis. The interactions of KM+ with both the extracellular matrix (ECM) and neutrophils depend on the lectin ability to recognize mannose-containing glycans. Here, we report the binding of KM+ to laminin and demonstrate that this interaction potentiates the KM+-induced neutrophil migration. Labeling of lung tissue by KM+ located its ligands on the endothelial cells, in the basement membrane, in the alveolus, and in the interstitial connective tissue. Such labeling was inhibited by 400 mM D-mannose, 10 mM Manalpha1-3[Manalpha1-6]Man or 10 microM peroxidase (a glycoprotein-containing mannosyl heptasaccharide). Laminin is a tissue ligand for KM+, since both KM+ and anti-laminin antibodies not only reacted with the same high molecular mass components of a lung extract, but also determined colocalized labeling in basement membranes of the lung tissue. The relevance of the KM+-laminin interaction to the KM+ property of inducing neutrophil migration was evaluated. The inability of low concentrations of soluble KM+ to induce human neutrophil migration was reversed by coating the microchamber filter with laminin. So, the interaction of KM+ with laminin promotes the formation of a substrate-bound KM+ gradient that is able to induce neutrophil haptotaxis.
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Affiliation(s)
- Luciane Ganiko
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, 14049-900, Ribeirão Preto, SP, Brazil
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211
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Asan E, Drenckhahn D. News and views in Histochemistry and Cell Biology. Histochem Cell Biol 2004; 122:593-621. [PMID: 15614519 DOI: 10.1007/s00418-004-0735-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2004] [Indexed: 11/29/2022]
Abstract
Advances in histochemical methodology and ingenious applications of novel and improved methods continue to confirm the standing of morphological means and approaches in research efforts, and contribute significantly to increasing our knowledge about structures and functions in all areas of the life sciences from cell biology to pathology. Reports published during recent months documenting this progress are summarized in the present review.
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Affiliation(s)
- Esther Asan
- Department of Anatomy and Cell Biology, University of Wuerzburg, Koellikerstrasse 6, 97070 Wuerzburg, Germany.
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212
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Hurley BP, Siccardi D, Mrsny RJ, McCormick BA. Polymorphonuclear Cell Transmigration Induced byPseudomonas aeruginosaRequires the Eicosanoid Hepoxilin A3. THE JOURNAL OF IMMUNOLOGY 2004; 173:5712-20. [PMID: 15494523 DOI: 10.4049/jimmunol.173.9.5712] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Lung inflammation resulting from bacterial infection of the respiratory mucosal surface in diseases such as cystic fibrosis and pneumonia contributes significantly to the pathology. A major consequence of the inflammatory response is the recruitment and accumulation of polymorphonuclear cells (PMNs) at the infection site. It is currently unclear what bacterial factors trigger this response and exactly how PMNs are directed across the epithelial barrier to the airway lumen. An in vitro model consisting of human PMNs and alveolar epithelial cells (A549) grown on inverted Transwell filters was used to determine whether bacteria are capable of inducing PMN migration across these epithelial barriers. A variety of lung pathogenic bacteria, including Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa are indeed capable of inducing PMN migration across A549 monolayers. This phenomenon is not mediated by LPS, but requires live bacteria infecting the apical surface. Bacterial interaction with the apical surface of A549 monolayers results in activation of epithelial responses, including the phosphorylation of ERK1/2 and secretion of the PMN chemokine IL-8. However, secretion of IL-8 in response to bacterial infection is neither necessary nor sufficient to mediate PMN transepithelial migration. Instead, PMN transepithelial migration is mediated by the eicosanoid hepoxilin A3, which is a PMN chemoattractant secreted by A549 cells in response to bacterial infection in a protein kinase C-dependent manner. These data suggest that bacterial-induced hepoxilin A3 secretion may represent a previously unrecognized inflammatory mechanism occurring within the lung epithelium during bacterial infections.
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Affiliation(s)
- Bryan P Hurley
- Mucosal Immunology Laboratory, Massachusetts General Hospital, Charlestown, MA 02129, USA
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213
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Abstract
The airflow limitation that defines chronic obstructive pulmonary disease (COPD) is the result of a prolonged time constant for lung emptying, caused by increased resistance of the small conducting airways and increased compliance of the lung as a result of emphysematous destruction. These lesions are associated with a chronic innate and adaptive inflammatory immune response of the host to a lifetime exposure to inhaled toxic gases and particles. Processes contributing to obstruction in the small conducting airways include disruption of the epithelial barrier, interference with mucociliary clearance apparatus that results in accumulation of inflammatory mucous exudates in the small airway lumen, infiltration of the airway walls by inflammatory cells, and deposition of connective tissue in the airway wall. This remodelling and repair thickens the airway walls, reduces lumen calibre, and restricts the normal increase in calibre produced by lung inflation. Emphysematous lung destruction is associated with an infiltration of the same type of inflammatory cells found in the airways. The centrilobular pattern of emphysematous destruction is most closely associated with cigarette smoking, and although it is initially focused on respiratory bronchioles, separate lesions coalesce to destroy large volumes of lung tissue. The panacinar pattern of emphysema is characterised by a more even involvement of the acinus and is associated with alpha1 antitrypsin deficiency. The technology needed to diagnose and quantitate the individual small airway and emphysema phenotypes present in people with COPD is being developed, and should prove helpful in the assessment of therapeutic interventions designed to modify the progress of either phenotype.
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Affiliation(s)
- James C Hogg
- James Hogg iCAPTURE Centre for Cardiovascular and Pulmonary Research, University of British Columbia and St Paul's Hospital, Room 166-1081, Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
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214
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Bench-to-bedside review: acute respiratory distress syndrome - how neutrophils migrate into the lung. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2004; 8:453-61. [PMID: 15566616 PMCID: PMC1065041 DOI: 10.1186/cc2881] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Acute lung injury and its more severe form, acute respiratory distress syndrome, are major challenges in critically ill patients. Activation of circulating neutrophils and transmigration into the alveolar airspace are associated with development of acute lung injury, and inhibitors of neutrophil recruitment attenuate lung damage in many experimental models. The molecular mechanisms of neutrophil recruitment in the lung differ fundamentally from those in other tissues. Distinct signals appear to regulate neutrophil passage from the intravascular into the interstitial and alveolar compartments. Entry into the alveolar compartment is under the control of CXC chemokine receptor (CXCR)2 and its ligands (CXC chemokine ligand [CXCL]1–8). The mechanisms that govern neutrophil sequestration into the vascular compartment of the lung involve changes in the actin cytoskeleton and adhesion molecules, including selectins, β2 integrins and intercellular adhesion molecule-1. The mechanisms of neutrophil entry into the lung interstitial space are currently unknown. This review summarizes mechanisms of neutrophil trafficking in the inflamed lung and their relevance to lung injury.
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215
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Liu Y, Shaw SK, Ma S, Yang L, Luscinskas FW, Parkos CA. Regulation of leukocyte transmigration: cell surface interactions and signaling events. THE JOURNAL OF IMMUNOLOGY 2004; 172:7-13. [PMID: 14688302 DOI: 10.4049/jimmunol.172.1.7] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Yuan Liu
- Epithelial Pathobiology Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
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216
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Nally JE, Chantranuwat C, Wu XY, Fishbein MC, Pereira MM, Da Silva JJP, Blanco DR, Lovett MA. Alveolar septal deposition of immunoglobulin and complement parallels pulmonary hemorrhage in a guinea pig model of severe pulmonary leptospirosis. THE AMERICAN JOURNAL OF PATHOLOGY 2004; 164:1115-27. [PMID: 14982864 PMCID: PMC1614724 DOI: 10.1016/s0002-9440(10)63198-7] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Human patients suffering from leptospirosis present with a diverse array of clinical manifestations, including the more severe and often fatal pulmonary form of the disease. The etiology of pulmonary hemorrhage is unclear. Isolates of Leptospira acquired from patients suffering from pulmonary hemorrhage were used to develop a guinea pig model of pulmonary hemorrhage. Gross findings post-infection confirmed extensive hemorrhage in the lungs and on peritoneal surfaces as the likely cause of death. Immunohistochemistry confirmed the presence of large numbers of leptospires in kidney, liver, intestinal tissues, and spleen, but few inflammatory cells were seen. In marked contrast, few leptospires were detected in infected hemorrhagic lung tissue. Blood chemistries and hematology did not reveal the etiology of the hemorrhage observed. There was no chemical or microscopic evidence for disseminated intravascular coagulation. To ascertain an immunopathologic role during disease, immunofluorescence was performed on infected lung tissues and confirmed the presence of IgM, IgG, IgA, and C3 along the alveolar basement membrane. This suggests that an autoimmune process may be the etiology of fatal pulmonary hemorrhage in leptospirosis.
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Affiliation(s)
- Jarlath E Nally
- Division of Infectious Diseases, Department of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA.
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217
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Ichiyasu H, McCormack JM, McCarthy KM, Dombkowski D, Preffer FI, Schneeberger EE. Matrix metalloproteinase-9-deficient dendritic cells have impaired migration through tracheal epithelial tight junctions. Am J Respir Cell Mol Biol 2003; 30:761-70. [PMID: 14656746 DOI: 10.1165/rcmb.2003-0370oc] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
When sampling inhaled antigens, dendritic cells (DC) must penetrate the tight junction (TJ) barrier while maintaining the TJ seal. In matrix metalloproteinase (MMP)-9-deficient mice, in vivo experiments suggest that migration of DC into air spaces is impaired. To examine the underlying mechanisms, we established a well-defined in vitro model using mouse tracheal epithelial cells and mouse bone marrow DC (BMDC). Transmigration was elicited with either macrophage inflammatory protein (MIP)-1alpha or MIP-3beta in a time-dependent manner. Control MMP-9(+/+) BMDC cultured with granulocyte macrophage-colony-stimulating factor for 7 d showed a 30-fold greater transepithelial migration toward MIP-3beta than MIP-1alpha, indicating a more mature DC phenotype. MMP-9(-/-) BMDC as well as MMP-9(+/+) BMDC in the presence of the MMP inhibitor GM6001, although showing a similar preference for MIP-3beta, were markedly impaired in their ability to traverse the epithelium. Expression levels of CCR5 and CCR7, however, were similar in both MMP-9(-/-) and MMP-9(+/+) BMDC. Expression of the integral TJ proteins, occludin and claudin-1, were examined in BMDC before and after transepithelial migration. Interestingly, occludin but not claudin-1 was degraded following transepithelial migration in both MMP-9(-/-) and control BMDC. In addition, there was a > 2-fold increase in claudin-1 expression in MMP-9(-/-) as compared with control BMDC. These observations indicate that occludin and claudin-1 are differentially regulated and suggest that the lack of MMP-9 may affect claudin-1 turnover.
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Affiliation(s)
- Hidenori Ichiyasu
- Molecular Pathology Unit, Department of Pathology, Massachusetts General Hospital, 149 13th Street, Charlestown, MA 02129, USA
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Sirianni FE, Chu FSF, Walker DC. Human alveolar wall fibroblasts directly link epithelial type 2 cells to capillary endothelium. Am J Respir Crit Care Med 2003; 168:1532-7. [PMID: 14551162 DOI: 10.1164/rccm.200303-371oc] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Alveolar wall fibroblasts directly link type 2 (T2) pneumocytes to capillary endothelium through apertures in their respective basal laminae in rabbit lung. These fibroblasts provide a bridge from the capillary to the airway lumen along which leukocytes may migrate without disrupting extracellular matrix. Normal human lungs were examined by transmission electron microscopy and serial section 3D reconstruction. We found contacts between fibroblasts and T2 pneumocytes and between fibroblasts and type 1 pneumocytes that occur at holes in the epithelial basal lamina. The same fibroblast also made contact with pericytes and endothelial cells through similar apertures. A survey of 41 T2 pneumocytes revealed that 54% of T2 pneumocytes had at least one gap in their basal lamina. A morphometric analysis showed these gaps occupied approximately 5.58 +/- 1.51% (mean +/- SE) of the area underneath T2 pneumocytes. We conclude that a population of single fibroblasts link T2 pneumocytes to adjacent capillary endothelial cells in alveolar walls of human lung. We propose that fibroblasts are organized to maintain communication between epithelium and mesenchyme and to provide directional information to migrating leukocytes.
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Affiliation(s)
- Faye E Sirianni
- iCAPTUR4E Center, McDonald Research Laboratories, University of British Columbia, St. Paul's Hospital, Vancouver, BC, V6Z 1Y6 Canada
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