| 1. |
- Abdillahi, Suado M, et al.
(författare)
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The Pulmonary Extracellular Matrix Is a Bactericidal Barrier Against Haemophilus influenzae in Chronic Obstructive Pulmonary Disease (COPD) : Implications for an in vivo Innate Host Defense Function of Collagen VI
- 2018
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Non-typeable Haemophilus influenzae (NTHi) is a Gram-negative human commensal commonly residing in the nasopharynx of preschool children. It occasionally causes upper respiratory tract infection such as acute otitis media, but can also spread to the lower respiratory tract causing bronchitis and pneumonia. There is increasing recognition that NTHi has an important role in chronic lower respiratory tract inflammation, particularly in persistent infection in patients suffering from chronic obstructive pulmonary disease (COPD). Here, we set out to assess the innate protective effects of collagen VI, a ubiquitous extracellular matrix component, against NTHi infection in vivo. In vitro, collagen VI rapidly kills bacteria through pore formation and membrane rupture, followed by exudation of intracellular content. This effect is mediated by specific binding of the von Willebrand A (VWA) domains of collagen VI to the NTHi surface adhesins protein E (PE) and Haemophilus autotransporter protein (Hap). Similar observations were made in vivo specimens from murine airways and COPD patient biopsies. NTHi bacteria adhered to collagen fibrils in the airway mucosa and were rapidly killed by membrane destabilization. The significance in host-pathogen interplay of one of these molecules, PE, was highlighted by the observation that it confers partial protection from bacterial killing. Bacteria lacking PE were more prone to antimicrobial activity than NTHi expressing PE. Altogether the data shed new light on the carefully orchestrated molecular events of the host-pathogen interplay in COPD and emphasize the importance of the extracellular matrix as a novel branch of innate host defense.
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| 2. |
- Akselsson, Cecilia, et al.
(författare)
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För Värmlands läns Luftvårdsförbund Övervakning av luftföroreningar i Värmlands län Resultat till och med september 1999
- 2000
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- På uppdrag av Värmlands läns Luftvårdsförbund har IVL mätt nedfall av luftföroreningar, markvattnets kvalitet och lufthalter på sju lokaler i Värmlands län. Syftet är att beskriva nedfallets storlek och markvattnets sammansättning i skogsytorna, men även visa skillnader mellan olika delar av regionen och hur förhållandena ändras med tiden. Vissa av provytorna ligger i Skogsvårdsorganisationens observationsytor, vilket gör att Luftvårdsförbundets data kan jämföras med skogens hälsa. Depositionen av svavel och kväve är störst i de sydvästra delarna av Sverige och avtar mot nordost. Denna gradient återfinns även i Värmlands län, där nästan 6 kg svavel deponerades per hektar i den sydligaste skogsytan Södra Averstad, medan omkring 2 kg/ha deponerades i Båtstad och Transtrandsberget i norr. De fyra ytor för vilka det finns en nioårig mätserie visar en markant minskning av svaveldeposition till skogsmark. Medelvärdet har minskat från omkring 7 kg/ha i början av 1990-talet till knappt 4 kg/ha, framför allt beroende på minskad torrdeposition. För kväve saknas motsvarande trend, medeldepositionen på öppet fält har varierat mellan 5 och 7 kg/ha. Prognoser visar att nedfallet år 2010 kommer att vara 2,5 kg svavel och 4 kg kväve per hektar i Svealand om beslutade utsläppsbegränsande åtgärder genomförs i Europa. Det minskade nedfallet av syror ska leda till en minskning av markvattnets försurningsgrad enligt modellberäkningar. Andra faktorer, som episoder av naturligt nedfall av havssalter, kan under kortare eller längre perioder dölja återhämtningen. Därför krävs det långa mätserier för att beskriva om markvattnets kvalitet verkligen förbättras. Markvattnets pH-värde har liksom tidigare år varit omkring 5, förutom ytan på Blåbärskullen centralt i Värmland, där förhållandena varit avsevärt bättre ur försurningsssynpunkt. Säsongsmedelhalten av marknära ozon, O3, var högre än året innan på grund av den fina sommaren 1999. Halterna har sannolikt varit skadliga för vegetationen. Däremot har luftens innehåll av svavel- och kvävedioxid varit betydligt under svenska miljökvalitetsnormer.
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| 3. |
- Alaridah, Nader, et al.
(författare)
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Mycobacteria Manipulate G-Protein-Coupled Receptors to Increase Mucosal Rac1 Expression in the Lungs
- 2017
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Ingår i: Journal of Innate Immunity. - : S. Karger AG. - 1662-811X .- 1662-8128. ; 9, s. 318-329
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Tidskriftsartikel (refereegranskat)abstract
- Mycobacterium bovis bacille Calmette-Guérin (BCG) is currently the only approved vaccine against tuberculosis (TB). BCG mimics M. tuberculosis (Mtb) in its persistence in the body and is used as a benchmark to compare new vaccine candidates. BCG was originally designed for mucosal vaccination, but comprehensive knowledge about its interaction with epithelium is currently lacking. We used primary airway epithelial cells (AECs) and a murine model to investigate the initial events of mucosal BCG interactions. Furthermore, we analysed the impact of the G-protein-coupled receptors (GPCRs), CXCR1 and CXCR2, in this process, as these receptors were previously shown to be important during TB infection. BCG infection of AECs induced GPCR-dependent Rac1 up-regulation, resulting in actin redistribution. The altered distribution of the actin cytoskeleton involved the MAPK signalling pathway. Blocking of the CXCR1 or CXCR2 prior to infection decreased Rac1 expression, and increased epithelial transcriptional activity and epithelial cytokine production. BCG infection did not result in epithelial cell death as measured by p53 phosphorylation and annexin. This study demonstrated that BCG infection of AECs manipulated the GPCRs to suppress epithelial signalling pathways. Future vaccine strategies could thus be improved by targeting GPCRs.
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| 4. |
- Andersson, Cecilia K, et al.
(författare)
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Activated MCTC mast cells infiltrate diseased lung areas in cystic fibrosis and idiopathic pulmonary fibrosis
- 2011
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Ingår i: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 12:139
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although mast cells are regarded as important regulators of inflammation and tissue remodelling, their role in cystic fibrosis (CF) and idiopathic pulmonary fibrosis (IPF) has remained less studied. This study investigates the densities and phenotypes of mast cell populations in multiple lung compartments from patients with CF, IPF and never smoking controls. Methods: Small airways, pulmonary vessels, and lung parenchyma were subjected to detailed immunohistochemical analyses using lungs from patients with CF (20 lung regions; 5 patients), IPF (21 regions; 7 patients) and controls (16 regions; 8 subjects). In each compartment the densities and distribution of MCT and MCTC mast cell populations were studied as well as the mast cell expression of IL-6 and TGF-beta. Results: In the alveolar parenchyma in lungs from patients with CF, MCTC numbers increased in areas showing cellular inflammation or fibrosis compared to controls. Apart from an altered balance between MCTC and MCT cells, mast cell in CF lungs showed elevated expression of IL-6. In CF, a decrease in total mast cell numbers was observed in small airways and pulmonary vessels. In patients with IPF, a significantly elevated MCTC density was present in fibrotic areas of the alveolar parenchyma with increased mast cell expression of TGF-beta. The total mast cell density was unchanged in small airways and decreased in pulmonary vessels in IPF. Both the density, as well as the percentage, of MCTC correlated positively with the degree of fibrosis. The increased density of MCTC, as well as MCTC expression of TGF-beta, correlated negatively with patient lung function. Conclusions: The present study reveals that altered mast cell populations, with increased numbers of MCTC in diseased alveolar parenchyma, represents a significant component of the histopathology in CF and IPF. The mast cell alterations correlated to the degree of tissue remodelling and to lung function parameters. Further investigations of mast cells in these diseases may open for new therapeutic strategies.
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| 5. |
- Andersson, Märta, et al.
(författare)
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Mycobacterium bovis bacilli Calmette-Guerin regulates leukocyte recruitment by modulating alveolar inflammatory responses.
- 2012
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Ingår i: Innate Immunity. - : SAGE Publications. - 1753-4267 .- 1753-4259. ; 18, s. 531-540
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Tidskriftsartikel (refereegranskat)abstract
- Leukocyte migration into the epithelial compartment is an important feature in the active phase of mycobacterial infections. In this study, we used the Transwell model to investigate the mechanisms behind mycobacteria-induced leukocyte recruitment and investigated the role of TLR2 and TLR4 in this process. Infection of epithelial cells resulted in significantly increased secretion of the neutrophil chemotactic CXCL8 and IL-6, but no secretion of monocyte chemotactic CCL2 or TNF-α was observed. In contrast to epithelial response, mycobacteria-infected neutrophils and monocytes secreted all these cytokines. Corresponding with epithelial cytokine response, mycobacterial infection of the epithelial cells increased neutrophil diapedesis, but decreased monocyte recruitment. However, monocyte recruitment towards mycobacteria infected epithelial cells significantly increased following addition of neutrophil pre-conditioned medium. Mycobacterial infection also increases alveolar epithelial expression of TLR2, but not TLR4, as analyzed by flow cytometry, Western blotting and visualized by confocal microscopy. Blocking of TLR2 inhibited neutrophil recruitment and cytokine secretion, while blocking of TLR4 had a lesser effect. To summarize, we found that primary alveolar epithelial cells produced a selective TLR2-dependent cytokine secretion upon mycobacterial infection. Furthermore, we found that cooperation between cells of the innate immunity is required in mounting proper antimicrobial defence.
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| 6. |
- Andersson Sjöland, Annika, et al.
(författare)
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Fibroblast phenotypes and their activity are changed in the wound healing process after lung transplantation.
- 2011
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Ingår i: The Journal of Heart and Lung Transplantation. - : Elsevier BV. - 1557-3117 .- 1053-2498. ; 30, s. 945-954
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Lung transplantation (LTx) is established as a life-saving treatment in end-stage lung disease. However, long-term survival is hampered by the development of chronic rejection, almost synonymous with bronchiolitis obliterans syndrome (BOS). The rejection is characterized by deposition of extracellular matrix in small airways. Fibroblasts/myofibroblasts are the main producers of extracellular matrix molecules such as proteoglycans. This study compared fibroblast phenotype and activity in the wound healing process at different points after LTx in patients who later did, or did not, develop BOS. METHODS: Distally derived fibroblasts from patients 6 and 12 months after LTx and from healthy controls were analyzed for production of the proteoglycans versican, perlecan, biglycan, and decorin, with and without transforming growth factor (TGF)-β(1). Fibroblast migration and proliferation were also studied. RESULTS: At 6 and 12 months after LTx, versican production was higher in fibroblasts from LTx patients (p < 0.01 p < 0.01) than from controls. Fibroblasts from patients who later developed BOS were more responsive to TGF-β(1)-induced synthesis of versican and biglycan than patients without signs of rejection (p < 0.05). Production of perlecan and decorin was negatively correlated with fibroblast proliferation in fibroblasts at 6 months after LTx. In a more detailed case study of 2 patients, one with and one without BOS, the altered proteoglycan profile was associated with impaired lung function. CONCLUSIONS: LTx changes the phenotype of fibroblasts to a non-proliferative but extracellular matrix-producing cell due to wound healing involving TGF-β(1). If not controlled, this may lead to development of BOS.
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| 7. |
- Andersson Sjöland, Annika, et al.
(författare)
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Versican in inflammation and tissue remodelling: the impact on lung disorders.
- 2015
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 25:3, s. 243-251
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Forskningsöversikt (refereegranskat)abstract
- Versican is a proteoglycan that has many different roles in tissue homeostasis and inflammation. The biochemical structure is comprised of four different types of the core protein with attached glycosaminoglycans that can be sulphated to various extents and has the capacity to regulate differentiation of different cell types, migration, cell adhesion, proliferation, tissue stabilization and inflammation. Versican's regulatory properties are of importance during both homeostasis and changes that lead to disease progression. The glycosaminoglycans that are attached to the core protein are of the chondroitin sulfate/dermatan sulfate type and are known to be important in inflammation through interactions with cytokines and growth factors. For a more complex understanding of versican it is of importance to study the tissue niche, where the wound healing process in both healthy and diseased conditions take place. In previous studies our group has identified changes in the amount of the multifaceted versican in chronic lung disorders such as asthma, chronic obstructive pulmonary disease and bronchiolitis obliterans syndrome, which could be a result of pathologic, transforming growth factor β driven, on-going remodelling processes. Reversely, the context of versican in its niche is of great importance since versican has been reported to have a beneficial role in other contexts e.g. emphysema. Here we explore the vast mechanisms of versican in healthy lung and in lung disorders.
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| 8. |
- Bagher, Mariam, et al.
(författare)
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Crosstalk between mast cells and lung fibroblasts is modified by alveolar extracellular matrix and influences epithelial migration
- 2021
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 22:2
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Tidskriftsartikel (refereegranskat)abstract
- Mast cells play an important role in asthma, however, the interactions between mast cells, fibroblasts and epithelial cells in idiopathic pulmonary fibrosis (IPF) are less known. The objectives were to investigate the effect of mast cells on fibroblast activity and migration of epithelial cells. Lung fibroblasts from IPF patients and healthy individuals were co-cultured with LAD2 mast cells or stimulated with the proteases tryptase and chymase. Human lung fibroblasts and mast cells were cultured on cell culture plastic plates or decellularized human lung tissue (scaffolds) to create a more physiological milieu by providing an alveolar extracellular matrix. Released mediators were analyzed and evaluated for effects on epithelial cell migration. Tryptase increased vascular endothelial growth factor (VEGF) release from fibroblasts, whereas co-culture with mast cells increased IL-6 and hepatocyte growth factor (HGF). Culture in scaffolds increased the release of VEGF compared to culture on plastic. Migration of epithelial cells was reduced by IL-6, while HGF and conditioned media from scaffold cultures promoted migration. In conclusion, mast cells and tryptase increased fibroblast release of mediators that influenced epithelial migration. These data indicate a role of mast cells and tryptase in the interplay between fibroblasts, epithelial cells and the alveolar extracellular matrix in health and lung disease.
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| 9. |
- Bagher, Mariam, et al.
(författare)
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Mast cells and mast cell tryptase enhance migration of human lung fibroblasts through protease-activated receptor 2
- 2018
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Ingår i: Cell Communication and Signaling. - : Springer Science and Business Media LLC. - 1478-811X. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mast cells may activate fibroblasts and contribute to remodeling processes in the lung. However, the mechanism behind these actions needs to be further investigated. Fibroblasts are major regulators of on-going remodeling processes. Protease activated receptor 2 (PAR2) expressed by fibroblasts may be activated by serine proteases, such as the mast cell mediator tryptase. The objective in this study was to investigate the effects of mast cells and specifically mast cell tryptase on fibroblast migration and the role of PAR2 activation. Methods: Human lung fibroblasts (HFL-1) were cultured together with human peripheral blood-derived mast cells or LAD2 mast cells and stimulated with either conditioned medium from LAD2 cells or tryptase. Analyses of immunological stimulation of mast cells by IgE/anti IgE in the co-culture system were also performed. The importance of PAR2 activation by mast cells and mast cell tryptase for the migratory effects of fibroblasts was investigated by pre-treatment with the PAR2 antagonist P2pal-18S. The expression of PAR2 was analyzed on fibroblasts and mast cells. Results: The migratory capacity of HFL-1 cells was enhanced by blood-derived mast cells (p < 0.02), LAD2 cells (p < 0.001), conditioned medium (p < 0.05) and tryptase (p < 0.006). P2pal-18S decreased the induced migration caused by mast cells (p < 0.001) and tryptase (p < 0.001) and the expression of PAR2 was verified in HFL-1 cells. Mast cells immunologically stimulated with IgE/Anti IgE had no further effects on fibroblast migration. Conclusions: Mast cells and the mast cell mediator tryptase may have crucial roles in inducing lung fibroblast migration via PAR-2 activation, which may contribute to remodeling processes in chronic lung diseases.
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| 10. |
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