| 1. |
- Egesten, Arne, et al.
(författare)
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The proinflammatory CXC-chemokines GRO-α/CXCL1 and MIG/CXCL9 are concomitantly expressed in ulcerative colitis and decrease during treatment with topical corticosteroids
- 2007
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Ingår i: International Journal of Colorectal Disease. - : Springer Science and Business Media LLC. - 0179-1958 .- 1432-1262. ; 22:12, s. 1421-1427
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Tidskriftsartikel (refereegranskat)abstract
- Background Ulcerative colitis is characterized by relapsing mucosal inflammation where the lesions include tissue-damaging granulocytes. In addition, T cells and natural killer (NK) cells play important pathophysiologic roles. Chemokines are a large family of peptides that play key roles in the regulation of inflammation. The CXC-chemokines, growth-related oncogene (GRO)-α/CXCL1 and interleukin (IL)-8/CXCL8, both recruit neutrophils and possess mitogenic properties, whereas the interferon-dependent CXC-chemokines monokine induced by gamma-interferon (MIG)/CXCL9, interferon-γ inducible protein of 10 kD/CXCL10, and IFN-inducible T cell alpha chemoattractant/CXCL11 recruit and activate T cells and NK cells. Materials and methods The expression of CXC-chemokines was studied in eight controls and in 11 patients suffering from ulcerative colitis in the distal part of the colon, before and during topical treatment with corticosteroids. Perfusates (obtained before, after 7 days, and after 28 days of treatment) and pinch biopsies (obtained before and after 28 days of treatment) were collected by colonoscopy. The rectal release of GRO-α and MIG was determined by enzyme-linked immunosorbent assay (ELISA), and tissue expression of the chemokines was detected in colonic tissue by immunohistochemistry. Results In perfusates, high levels of GRO-α, IL-8, and MIG were detected compared with controls (p = 0.02, 0.005, and p = 0.03, respectively). During treatment with corticosteroids, both GRO-α and MIG decreased. In clinical nonresponders, characterized by sustained inflammation, the levels of GRO-α and MIG remained elevated. Both epithelial cells and granulocytes, present in the submucosa, expressed GRO-α and MIG as detected by immunohistochemistry. Conclusions CXC-chemokines are likely to be important in the pathophysiology of ulcerative colitis and may become targets for novel treatment strategies. In addition, GRO-α may serve as a marker of disease activity.
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| 2. |
- Jovic, Sandra, et al.
(författare)
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Expression of MIG/CXCL9 in Cystic Fibrosis and Modulation of Its Activities by Elastase of Pseudomonas aeruginosa.
- 2014
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Ingår i: Journal of Innate Immunity. - : S. Karger AG. - 1662-811X .- 1662-8128. ; 6:6, s. 846-859
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Tidskriftsartikel (refereegranskat)abstract
- In cystic fibrosis (CF), colonization of the airways with Pseudomonas aeruginosa is associated with disease deterioration. The mechanism behind the disease progression is not fully understood. The present work shows that the antibacterial chemokine MIG/CXCL9 is present in the airways and in sputum of CF patients. MIG/CXCL9 showed high bactericidal activity against. P. aeruginosa, including some strains from the airways of CF patients. Full-length MIG/CXCL9 was detected in sputum from healthy controls and CF patients colonized with P. aeruginosa. However, degraded MIG/CXCL9 was only found in CF sputum. In vitro, elastase of P. aeruginosa cleaved off a fragment of similar size and two additional fragments from MIG/CXCL9. The fragments showed less bactericidal activity against P. aeruginosa compared with the full-length protein. The fragments did not activate the MIG/CXCL9 receptor CXCR3 (expressed e.g. by NK cells, mast cells, and activated T cells) but instead displayed noncompetitive inhibition. In vitro, a decrease in CXCR3-bearing cells was found within and in the proximity of the bronchial epithelium of CF lung tissue compared with controls. Taken together, both bactericidal and cell-recruiting activities of MIG/CXCL9 are corrupted by P. aeruginosa through release of elastase, and this may contribute to impaired airway host defense in CF. © 2014 S. Karger AG, Basel.
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| 3. |
- Jovic, Sandra, et al.
(författare)
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The neutrophil-recruiting chemokine GCP-2/CXCL6 is expressed in cystic fibrosis airways and retains its functional properties after binding to extracellular DNA.
- 2016
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Ingår i: Mucosal Immunology. - : Elsevier BV. - 1933-0219. ; 9:1, s. 112-123
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Tidskriftsartikel (refereegranskat)abstract
- Infections in cystic fibrosis (CF), often involving Pseudomonas aeruginosa, result from a dysregulated airway immunity where one hallmark is the accumulation of necrotic and apoptotic immune cells, in particular neutrophils. In addition, neutrophils actively release DNA, forming neutrophil extracellular traps (NETs) that contain antimicrobial proteins. Altogether, free DNA in complex with actin accumulates in the airway lumen, resulting in highly viscous sputum that provides an anionic matrix, binding cationic antimicrobial proteins. In this study, granulocyte chemotactic protein 2 (GCP-2)/CXCL6, a neutrophil-activating chemokine with bactericidal properties, was detected in the airway epithelium of CF patients and was also present in azurophilic and specific granules of neutrophils. Elastase of neutrophils, but not of P. aeruginosa, completely degraded CXCL6 (chemokine (C-X-C motif) ligand 6). In addition, CXCL6 colocalized with extracellular DNA in both CF sputa and in in vitro-formed NETs. In vitro, CXCL6 bound DNA with a KD of 2,500 nM. Interestingly, both the bactericidal and the receptor-activating properties of CXCL6 (against neutrophils) remained largely unaffected in the presence of DNA. However, the chemotactic properties of CXCL6 were reduced by the presence of DNA. Taken together, CXCL6 is expressed in CF, retaining its functional properties even after binding to the anionic scaffold that extracellular DNA provides in CF.Mucosal Immunology advance online publication, 20 May 2015; doi:10.1038/mi.2015.43.
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| 4. |
- Kilsgård, Ola, et al.
(författare)
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Peptidylarginine deiminases present in the airways during tobacco smoking and inflammation can citrullinate the host defense peptide LL-37, resulting in altered activities.
- 2012
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Ingår i: American journal of respiratory cell and molecular biology. - 1535-4989 .- 1044-1549. ; 46:2, s. 240-8
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial colonization of the lower respiratory tract is frequently seen in chronic obstructive pulmonary disease (COPD), and may cause exacerbations leading to disease progression. Antimicrobial peptides comprise an important part of innate lung immunity, and not least the cathelicidin human cationic antimicrobial protein-18/LL-37. Peptidylarginine deiminases (PADIs) post-translationally modify proteins by converting cationic peptidylarginine residues to neutral peptidylcitrulline. An increased presence of PADI2 and citrullinated proteins was demonstrated in the lungs of smokers. In this study, preformed PADI4, stored in granulocytes and extracellularly in the lumina of bronchi, was found in lung tissue of individuals suffering from COPD. In vitro, recombinant human PADI2 and PADI4 both caused a time- and dose-dependent citrullination of LL-37. The citrullination resulted in impaired antibacterial activity against Staphylococcus aureus, Streptococcus pneumoniae, and nontypable Haemophilus influenzae, but less so against Pseudomonas aeruginosa. Using artificial lipid bilayers, we observed discrete differences when comparing the disrupting activity of native and citrullinated LL-37, suggesting that differences in cell wall composition are important during interactions with whole bacteria. Furthermore, citrullinated LL-37 showed higher chemotactic activity against mononuclear leukocytes than did native LL-37, but was less efficient at neutralizing lipolysaccharide, and also in converting apoptotic neutrophils into a state of secondary necrosis. In addition, citrullinated LL-37 was more prone to degradation by proteases, whereas the V8 endopetidase of S. aureus cleaved the modified peptide at additional sites, compared with native LL-37. Together, these findings demonstrate novel mechanisms whereby the inflammation-dependent deiminases PADI2 and PADI4 can alter the activites of antibacterial polypeptides, affecting the course of inflammatory disorders such as COPD.
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| 5. |
- Linge, Helena, et al.
(författare)
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Midkine is expressed and differentially processed during COPD exacerbations and ventilator-associated pneumonia associated with Staphylococcus aureus infection.
- 2013
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Ingår i: Molecular medicine (Cambridge, Mass.). - : Springer Science and Business Media LLC. - 1528-3658 .- 1076-1551. ; 19, s. 314-323
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus is sometimes isolated from the airways during acute exacerbations of chronic obstructive pulmonary disease (COPD) but more commonly recognized as a cause of ventilator-associated pneumonia (VAP). Antimicrobial proteins, among them midkine (MK), are an important part of innate immunity in the airways. In this study, the levels and possible processing of MK in relation to S. aureus infection of the airways were investigated, comparing COPD and VAP, thus comparing a state of disease with preceding chronic inflammation and remodeling (COPD) with acute inflammation (i.e. VAP). MK was detected in the small airways and alveoli of COPD lung tissue but less so in normal lung tissue. MK at below micromolar concentrations killed S. aureus in vitro. Proteolytic processing of MK by the staphylococcal metalloprotease AL but not cysteine protease SA, resulted in impaired bactericidal activity. Degradation was foremost seen in the COOH-terminal portion of the molecule that harbors high bactericidal activity. In addition, MK was detected in sputum from patients suffering from VAP caused by S. aureus but less so in sputum from COPD-exacerbations associated with the same bacterium. Recombinant MK was degraded more rapidly in sputum from the COPD patients than from the VAP patients and a greater proteolytic activity in COPD sputum was confirmed by zymography. Taken together, proteases of both bacteria and the host contribute to degradation of the antibacterial protein MK, resulting in an impaired defense of the airways, in particular in COPD where the state of chronic inflammation could be of importance.
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| 6. |
- Skogvall, Staffan, et al.
(författare)
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Oral iodinated activated charcoal improves lung function in patients with COPD.
- 2014
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 1532-3064 .- 0954-6111. ; 108:6, s. 905-909
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Tidskriftsartikel (refereegranskat)abstract
- The effect of 8 weeks treatment with oral iodinated activated charcoal (IAC) on lung function of patients with moderate chronic obstructive pulmonary disease (COPD) was examined in a double blind randomized placebo controlled parallel group study with 40 patients. In the IAC group, patients showed a statistically significant improvement of FEV1 baseline by 130 ml compared to placebo, corresponding to 8.2% improvement (p = 0.031*). Correlation statistics revealed that the improvement of FEV1 baseline was significantly correlated both to FEV1 post-bronchodilator (p = 0.0020**) and FEV1 post-exercise (0.033*) values. This demonstrates that the improved baseline lung function by IAC did not inhibit a further beta2-adrenoceptor relaxation, and thus that patients did not reach a limit for maximal improvement of the lung function after IAC treatment. Eight patients in the IAC group developed abnormal thyroid hormone levels transiently during the treatment. This side effect was not correlated to improvement of lung function (p = 0.82). No serious adverse effects directly related to the treatment were recorded. In summary, this study demonstrates that iodinated activated charcoal surprisingly and significantly improved lung function of patients with moderate COPD. The underlying mechanism of action is unclear, but is likely to be different from the drugs used today. The immediate conclusion is that further studies are now justified in order to determine clinical efficacy of IAC in COPD and explore possible mechanisms of action.
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