| 1. |
- Andersson, Cecilia, et al.
(författare)
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Mice Lacking 12/15-Lipoxygenase have Attenuated Airway Allergic Inflammation and Remodeling.
- 2008
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Ingår i: American Journal of Respiratory Cell and Molecular Biology. - 1535-4989. ; 39:6, s. 648-656
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Tidskriftsartikel (refereegranskat)abstract
- Arachidonate 15-lipoxygenase (LO)-1 has been implicated in allergic inflammation and asthma. The overall effect of 15-LO in allergic inflammation in vivo is, however, unclear. This study investigates systemic allergen sensitization and local allergic airway inflammation and remodeling in mice lacking the murine 12/15-LO, the ortholog to human 15-LO-1. Upon systemic sensitization with intraperitoneal ovalbumin, 12/15 LO(-/-) mice produced elevated levels of allergen-specific IgE compared to wild type (Wt) controls. However, when challenged with repeated aerosolized allergen sensitized 12/15 LO(-/-) mice had an impaired development of airway allergic inflammation compared to Wt controls, as indicated by reduced BAL fluid leukocytes (eosinophils, lymphocytes macrophages) and Th2 cytokines (IL-4, IL-5, IL-13) as well as tissue eosinophils. Allergen-induced airway epithelial proliferation was also significantly attenuated in 12/15 LO(-/-) mice whereas goblet cell hyperplasia was unaffected. However, 12/15 LO(-/-) mice had significantly reduced luminal mucus secretions compared to Wt controls. The repeated allergen challenges resulted in a dramatic increase of alpha-smooth muscle-actin positive alveolar cells in the peripheral airways, a phenomenon that was significantly less developed in 12/15 LO(-/-) mice. In conclusion, our data suggest that 12/15 LO(-/-) mice, although having a fully developed systemic sensitization, did not establish a fully developed allergic airway inflammation and associated manifestations of central and peripheral airway remodeling. These data suggest that 12/15-LO derived metabolites play an important pathophysiological role in allergen-induced inflammation and remodeling. Hence, pharmacologic targeting of the human 15-LO-1 may represent an attractive therapeutic strategy to control inflammation and remodeling in asthma.
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| 2. |
- Andersson Sjöland, Annika, et al.
(författare)
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ROS-induced endothelial stress contributes to pulmonary fibrosis through pericytes and Wnt signaling.
- 2015
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Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837.
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary fibrosis is a grave diagnosis with insidious progression, generally considered as a consequence of aberrant epithelial wound healing and excessive scarring. This process is commonly modeled in animals by local bleomycin administration, resulting in peribronchial inflammation and subsequent fibrosis. We have previously described initiation and early development of distal pulmonary fibrosis following repeated subcutaneous bleomycin injections (systemic administration). The aim of this study was to identify mechanisms for the development of pulmonary fibrosis, which we hypothesize is related to endothelial stress and activation. Bleomycin was administered subcutaneously 3 times/week during 0.33-4w, and parenchymal alterations were studied. In addition, we used microvascular endothelial cells to investigate effects of bleomycin in vitro. Our results confirmed that systemic administration of bleomycin exerts oxidative stress indicated by an increase in Sod1 at 0.33, 1, and 4w (P<0.05). Endothelial cells were activated (increased CD106 expression) from 1w and onwards (P<0.05), and p21 expression was increased 2-3 times throughout the study (P<0.05) as were the number of β-catenin-positive nuclei (P<0.001). Wnt3a was increased at 0.33, 1, and 4w (P<0.01) and Wnt5a from 1w and onwards (P<0.001). The present study suggests that bleomycin-induced reactive oxygen species (ROS) causes DNA stress affecting the endothelial niche, initiating repair processes including Wnt signaling. The repeated systemic administrations disrupt a normally fine-tuned balance in the Wnt signaling. In addition, pericyte differentiation was affected, which may have significant effects on fibrosis due to their ability to differentiate into myofibroblasts. We conclude that the endothelial niche may have an important role in the development of pulmonary fibrosis and warrants further investigations.Laboratory Investigation advance online publication, 14 September 2015; doi:10.1038/labinvest.2015.100.
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| 3. |
- 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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| 4. |
- Andréasson, Kristofer, et al.
(författare)
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Limited impact of fibromodulin deficiency on the development of experimental skin fibrosis
- 2016
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Ingår i: Experimental Dermatology. - : Wiley. - 0906-6705.
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Tidskriftsartikel (refereegranskat)abstract
- Excessive production of collagen is the hallmark of fatal diseases of fibrosis such as systemic sclerosis. Overexpression of the proteoglycan fibromodulin (FMOD) has been associated with improved wound healing and scarless repair. In this study we have investigated the consequences of FMOD deficiency on the development of experimental skin fibrosis. Using immunohistochemistry, we identified FMOD in both human and murine fibrotic skin. In the bleomycin model of skin fibrosis, FMOD(-/-) mice developed skin fibrosis to a similar degree compared to FMOD(+/+) mice. Analysis of skin ultrastructure using transmission electron microscopy revealed a significant reduction in collagen fibril diameter in FMOD(-/-) but not FMOD(+/+) mice following fibrosis. We conclude that impact of FMOD deficiency on the development of experimental skin fibrosis is limited. This article is protected by copyright. All rights reserved.
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| 5. |
- Bölükbas, Deniz, et al.
(författare)
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Preclinical evidence for the role of stem/stromal cells in COPD
- 2019. - 1
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Ingår i: Stem Cell-Based Therapy for Lung Disease. - Cham : Springer International Publishing. - 9783030294021 - 9783030294038 ; , s. 73-96
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Bokkapitel (refereegranskat)abstract
- Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide and there are currently limited treatment options for these patients. The disease is characterized by a reduction in airflow due to chronic bronchitis, as well as airspace enlargement in the distal lung, resulting in a loss of surface area available for gas exchange. At end-stage disease, oxygen therapy and lung transplantation remain the only potential options. The disease is heterogeneous and both inflammatory cells as well as structural cells are thought to play a role in disease onset and progression. Pharmaceutical approaches are ineffective at reversing disease pathology and currently aim only to provide symptomatic relief. A recent area of investigation focuses on exogenous cell therapy, including stem cell administration, and its potential for directing lung regeneration. Cell therapies from a variety of sources, as well as cell-derived products such as extracellular vesicles, have recently shown efficacy in animal models of COPD, but early clinical trials have not yet shown efficacy. In this chapter, we discuss the different animal models of COPD as well as the studies which have been conducted to date with cell therapies. We conclude the chapter with a discussion regarding the limitations of current animal models and discuss potential areas for future study.
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| 6. |
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| 7. |
- Ke, Hengning, et al.
(författare)
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Nemo-like kinase regulates the expression of vascular endothelial growth factor (VEGF) in alveolar epithelial cells
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- The canonical Wnt signaling can be silenced either through β-catenin-mediated ubiquitination and degradation or through phosphorylation of Tcf and Lef by nemo-like kinase (NLK). In the present study, we generated NLK deficient animals and found that these mice become cyanotic shortly before death because of lung maturation defects. NLK-/- lungs exhibited smaller and compressed alveoli and the mesenchyme remained thick and hyperplastic. This phenotype was caused by epithelial activation of vascular endothelial growth factor (VEGF) via recruitment of Lef1 to the promoter of VEGF. Elevated expression of VEGF and activation of the VEGF receptor through phosphorylation promoted an increase in the proliferation rate of epithelial and endothelial cells. In summary, our study identifies NLK as a novel signaling molecule for proper lung development through the interconnection between epithelial and endothelial cells during lung morphogenesis.
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| 8. |
- Löfdahl, Anna, et al.
(författare)
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5-HT2B receptor antagonists attenuate myofibroblast differentiation and subsequent fibrotic responses in vitro and in vivo
- 2016
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Ingår i: Physiological Reports. - : Wiley. - 2051-817X. ; 4:15
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary fibrosis is characterized by excessive accumulation of connective tissue, along with activated extracellular matrix (ECM)-producing cells, myofibroblasts. The pathological mechanisms are not well known, however serotonin (5-HT) and 5-HT class 2 (5-HT2) receptors have been associated with fibrosis. The aim of the present study was to investigate the role of 5-HT2B receptors in fibrosis, using small molecular 5-HT2B receptor antagonists EXT5 and EXT9, with slightly different receptor affinity. Myofibroblast differentiation [production of alpha-smooth muscle actin (α-SMA)] and ECM synthesis were quantified in vitro, and the effects of the receptor antagonists were evaluated. Pulmonary fibrosis was also modeled in mice by subcutaneous bleomycin administrations (under light isoflurane anesthesia), and the effects of receptor antagonists on tissue density, collagen-producing cells, myofibroblasts and decorin expression were investigated. In addition, cytokine expression was analyzed in serum. Lung fibroblasts displayed an increased α-SMA (P < 0.05) and total proteoglycan production (P < 0.01) when cultured with TGF-β1 together with 5-HT, which were significantly reduced with both receptor antagonists. Following treatment with EXT5 or EXT9, tissue density, expression of decorin, number of collagen-producing cells, and myofibroblasts were significantly decreased in vivo compared to bleomycin-treated mice. Receptor antagonization also significantly reduced systemic levels of TNF-α and IL-1β, indicating a role in systemic inflammation. In conclusion, 5-HT2B receptor antagonists have potential to prevent myofibroblast differentiation, in vitro and in vivo, with subsequent effect on matrix deposition. The attenuating effects of 5-HT2B receptor antagonists on fibrotic tissue remodeling suggest these receptors as novel targets for the treatment of pulmonary fibrosis.
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| 9. |
- Löfdahl, Anna, et al.
(författare)
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Effects of 5-Hydroxytryptamine Class 2 Receptor Antagonists on Bronchoconstriction and Pulmonary Remodeling Processes
- 2018
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Ingår i: American Journal of Pathology. - : Elsevier BV. - 0002-9440. ; 188:5, s. 1113-1119
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Tidskriftsartikel (refereegranskat)abstract
- Serotonin [5-hydroxytryptamine (5-HT)] is associated with several chronic pulmonary diseases, recognizing 5-HT2 receptor antagonists as potential inhibitors of tissue remodeling. However, the effects of 5-HT2 receptors, especially 5-HT2B receptors on airway function and remodeling, are unclear. We investigated the role of 5-HT2B receptors on airway smooth muscle contractility and remodeling processes. Murine precision-cut lung slices were pretreated with 5-HT2B receptor antagonists (EXT5, EXT9, RS 127445, and PRX 08066), as well as ketanserin (5-HT2A/2C receptor antagonist) (1, 10 μmol/L), before addition of cumulative concentrations of 5-HT to induce bronchoconstriction. Remodeling effects after treatment with 10 μmol/L 5-HT and 5-HT2 receptor antagonists were further studied in distal lung tissue by examining release of profibrotic transforming growth factor (TGF)-β1 and proliferation of human bronchial smooth muscle cells (HBSMCs). 5-HT–induced bronchoconstriction was significantly reduced by EXT5, EXT9, and ketanserin, but not by RS 127445 or PRX 08066. The 5-HT2B receptor antagonists significantly reduced TGF-β1 release. 5-HT, in combination with TGF-β1, increased proliferation of HBSMCs, a process reduced by EXT5 and EXT9. Our results indicate that EXT5 and EXT9 may relieve bronchoconstriction in murine airways and serve as an add-on effect in attenuating pulmonary remodeling by improving airway function. The antiproliferative effect on HBSMCs and the inhibition of TGF-β1 release further support a role of 5-HT2B receptors in pathologic remodeling processes.
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| 10. |
- Löfdahl, Anna, et al.
(författare)
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Pulmonary fibrosis in vivo displays increased p21 expression reduced by 5-HT2B receptor antagonists in vitro - A potential pathway affecting proliferation
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Serotonin (5-hydroxytryptamine) has repeatedly been associated with the development of fibrotic disorders such as pulmonary fibrosis. By blocking the binding of 5-HT to 5-HT2B receptors with receptor antagonists, several pro-fibrotic mechanisms can be inhibited. Bleomycin-induced pulmonary fibrosis is a model used to evaluate pathological mechanisms and pharmacological interventions. Previously we have shown attenuated fibrosis in systemic bleomycin-treated mice following treatment with two 5-HT2B receptor antagonists (EXT5 and EXT9). Our aim is to further identify cellular effects and signaling pathways associated with the anti-fibrotic effects of EXT5/9. Gene expressions in lung tissues from systemic bleomycin-treated mice were examined, revealing significant increased expression of Cdkn1α (a gene coding for p21), particularly in distal regions of the lung. In vitro studies in human lung fibroblasts revealed increased levels of p21 (p = 0.0032) and pAkt (p = 0.12) following treatment with 5-HT (10 μM). The induction of p21 and pAkt appears to be regulated by 5-HT2B receptors, with diminished protein levels following EXT9-treatment (p21 p = 0.0024, pAkt p = 0.15). Additionally, 5-HT induced fibroblast proliferation, an event significantly reduced by EXT5 (10 μM) and EXT9 (10 μM). In conclusion, our results suggest that 5-HT2B receptor antagonism attenuates pulmonary fibrosis in part by anti-proliferative effects, associated with inhibited pAkt/p21 signaling pathway.
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