| 1. |
- Andersson, Cecilia, et al.
(author)
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Mice Lacking 12/15-Lipoxygenase have Attenuated Airway Allergic Inflammation and Remodeling.
- 2008
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In: American Journal of Respiratory Cell and Molecular Biology. - 1535-4989. ; 39:6, s. 648-656
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Journal article (peer-reviewed)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.
(author)
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ROS-induced endothelial stress contributes to pulmonary fibrosis through pericytes and Wnt signaling.
- 2015
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In: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837.
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Journal article (peer-reviewed)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.
(author)
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Versican in inflammation and tissue remodelling: the impact on lung disorders.
- 2015
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In: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 25:3, s. 243-251
-
Research review (peer-reviewed)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.
(author)
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Limited impact of fibromodulin deficiency on the development of experimental skin fibrosis
- 2016
-
In: Experimental Dermatology. - : Wiley. - 0906-6705.
-
Journal article (peer-reviewed)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.
(author)
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Preclinical evidence for the role of stem/stromal cells in COPD
- 2019. - 1
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In: Stem Cell-Based Therapy for Lung Disease. - Cham : Springer International Publishing. - 9783030294021 - 9783030294038 ; , s. 73-96
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Book chapter (peer-reviewed)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.
(author)
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Nemo-like kinase regulates the expression of vascular endothelial growth factor (VEGF) in alveolar epithelial cells
- 2016
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
-
Journal article (peer-reviewed)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.
(author)
-
5-HT2B receptor antagonists attenuate myofibroblast differentiation and subsequent fibrotic responses in vitro and in vivo
- 2016
-
In: Physiological Reports. - : Wiley. - 2051-817X. ; 4:15
-
Journal article (peer-reviewed)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.
(author)
-
Effects of 5-Hydroxytryptamine Class 2 Receptor Antagonists on Bronchoconstriction and Pulmonary Remodeling Processes
- 2018
-
In: American Journal of Pathology. - : Elsevier BV. - 0002-9440. ; 188:5, s. 1113-1119
-
Journal article (peer-reviewed)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.
(author)
-
Pulmonary fibrosis in vivo displays increased p21 expression reduced by 5-HT2B receptor antagonists in vitro - A potential pathway affecting proliferation
- 2018
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
-
Journal article (peer-reviewed)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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| 11. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Aberrant nonfibrotic parenchyma in idiopathic pulmonary fibrosis is correlated with decreased β-catenin inhibition and increased Wnt5a/b interaction
- 2016
-
In: Physiological Reports. - : Wiley. - 2051-817X. ; 4:5
-
Journal article (peer-reviewed)abstract
- Idiopathic pulmonary fibrosis (IPF), an insidious disease with grave prognosis, is characterized by heterogeneous fibrosis with densely fibrotic areas surrounded by nonfibrotic normal-looking tissue, believed to reflect a temporal development. The etiology is incompletely elucidated, but aberrant wound healing is believed to be involved. Embryonic signaling pathways, including Wnt signaling, are reactivated in wound healing, and we therefore aimed to investigate Wnt signaling, and hypothesized that Wnt signaling would correspond to degree of fibrosis. Material from 10 patients with IPF were included (four diagnostic biopsies and six donated lungs) and compared to healthy controls (n = 7). We investigated markers of Wnt signaling (β-catenin, Wnt3a, ICAT, Wnt5a/b, DAAM1 and NLK) histologically in lung parenchyma with variable degree of fibrosis. Our results suggest that Wnt signaling is significantly altered (P < 0.05) already in normal-looking parenchyma. The expression of Wnt3a and ICAT decreased (both P < 0.01) in IPF compared to healthy lungs, whereas β-catenin, Wnt5a/b, DAAM1 and NLK increased (P < 0.05 for all). ICAT is further decreased in dense fibrosis compared to normal-looking parenchyma in IPF (P < 0.001). On the basis of our results, we conclude that from a Wnt perspective, there is no normal parenchyma in IPF, and Wnt signaling corresponds to degree of fibrosis. In addition, β-catenin and Wnt5a appears coupled, and decreased inhibition of β-catenin may be involved. We suggest that the interaction between β-catenin, ICAT, and Wnt5a/b may represent an important research area and potential target for therapeutic intervention.
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| 12. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Absence of fibromodulin affects matrix composition, collagen deposition and cell turnover in healthy and fibrotic lung parenchyma.
- 2014
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 4
-
Journal article (peer-reviewed)abstract
- The ECM exerts great effects on cells, and changed composition may therefore have profound impact. Small leucine-rich proteoglycans, e.g. fibromodulin, are essential in collagen assembly. Our aim was to investigate the role of fibromodulin in healthy and fibrotic lung parenchyma, theorizing that fibromodulin-deficient animals would be protected against fibrosis. Repeated subcutaneous bleomycin-injections were given to wild type and fibromodulin-deficient mice, inducing pulmonary fibrosis. Development of fibrosis, ECM composition, cell turnover and inflammatory responses were investigated. Fibromodulin-deficient animals were not protected from fibrosis, but the composition of the matrix was affected, with decreased Collagen I in fibromodulin-deficient animals, both in controls (0.07 ± 0.04% vs. 0.18 ± 0.07% tissue area) and after bleomycin (0.37 ± 0.16% vs. 0.61 ± 0.21% tissue area). Biglycan was increased in fibromodulin-deficient animals, whereas decorin was decreased. Furthermore, bleomycin increased cell turnover in wild type, but only proliferation in fibromodulin-deficient animals, resulting in hyperplasia. In addition, the bleomycin-induced immune response was affected in fibromodulin-deficient animals. We thus conclude that fibromodulin has a profound effect on ECM, both in healthy and fibrotic lung parenchyma, and may be providing a permissive microenvironment affecting cell turnover. Furthermore, this study highlights the need to acknowledge specific ECM components, when assessing tissue properties and ultimately cell behaviour.
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| 13. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Allergen-exposure of Mouse Airways Evokes Remodeling of both Bronchi and Large Pulmonary Vessels.
- 2005
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In: American Journal of Respiratory and Critical Care Medicine. - 1535-4970. ; 171:1, s. 19-25
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Journal article (peer-reviewed)abstract
- Remodeling of airway structures is a well-documented feature of allergic airway inflammation. To investigate whether bronchial remodeling is associated with remodeling of adjacent pulmonary vessels, sensitized mice were subjected to repeated ovalbumin inhalations, and bronchi and pulmonary vessels were subjected to histologic analysis. Allergen challenges induced peribronchial as well as perivascular eosinophilia. Remodeling of systemic airway microcirculation, as studied in tracheal whole-mount preparations, revealed an allergen-induced increase in both the diameter and length of the airway microvessels. Immunostaining for alpha-smooth muscle actin disclosed an increase in smooth muscle mass in both bronchi and large pulmonary vessels. Both bronchi and pulmonary vessels also displayed increased expression of procollagen I and procollagen III. Staining for proliferating cell nuclear antigen revealed increased proliferation of bronchial epithelial and smooth muscle cells as well as pulmonary vascular endothelial and smooth muscle cells. We conclude that central features of remodeling that take place in allergen-exposed airways are present also in the pulmonary vessels. The significance of this finding with respect to occurrence in disease, pathophysiologic importance, and involved mechanisms warrants further investigation.
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| 14. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Allergic Airway Inflammation Initiates Long-Term Vascular Remodeling of the Pulmonary Circulation.
- 2009
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In: International Archives of Allergy and Immunology. - : S. Karger AG. - 1423-0097 .- 1018-2438. ; 149:3, s. 251-258
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Journal article (peer-reviewed)abstract
- Background: Asthma and allergic airway inflammation are associated with persistent structural alterations in the bronchi, i.e. airway remodeling. Previous studies have shown that during allergic airway inflammation, similar structural alterations may also be evoked in the pulmonary circulation. However, it remained unknown whether remodeling of the pulmonary circulation is as persistent as airway remodeling. The aim of this study is to investigate the reversibility and resolution of vascular remodeling, induced by allergic airway inflammation. Methods: A validated mouse model of allergic airway inflammation, utilizing ovalbumin as allergen, was employed. Animals were sacrificed 1 day, 1 week or 1 month after the last allergen exposure, and different parameters of remodeling (smooth muscle mass, proliferation of smooth muscle cells and endothelial cells as well as number of myofibroblasts and procollagen-I-producing cells) were investigated and quantified histologically. Results: Allergen exposure resulted in allergic airway inflammation characterized by a transient leukocyte infiltration and in structural alterations in both airway and vascular compartments. The increase in vascular smooth muscle mass and endothelial proliferation persisted at 1 month after the last allergen exposure. The other parameters and cellular inflammatory response returned to baseline within 1 month after the last allergen challenge. Conclusions: Based on the findings in this study, we conclude that acute allergic airway inflammation, although being initiated from the airways, is able to evoke similar long-term structural alterations in pulmonary vessels as described for bronchi.
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| 15. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Direct evidence of secondary necrosis of neutrophils during intense lung inflammation.
- 2006
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In: European Respiratory Journal. - : European Respiratory Society (ERS). - 1399-3003 .- 0903-1936. ; 28:2, s. 268-274
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Journal article (peer-reviewed)abstract
- Several pulmonary inflammatory conditions are characterised by infiltration of neutrophils. Normally, neutrophils are silently removed by apoptosis, followed by phagocytosis. However, if phagocytosis fails, apoptotic cells undergo secondary necrosis. Recent findings of increased levels of the pan-necrosis marker lactate dehydrogenase in bronchoalveolar lavage from lipopolysaccharide-exposed mice implies potential involvement of secondary necrosis. Using a similar model, this study aimed to identify the source of lactate dehydrogenase and to search for direct histological evidence of secondary necrosis. Lipopolysaccharide (LPS) was administered to the lungs of BALB/c mice, and bronchoalveolar lavage and tissue samples were collected 4, 12, 24, 36, 48, 60 and 72 h after administration. LPS induced a patchy neutrophil-rich lung inflammation, where the numbers of terminal deoxynucleotide transferase-mediated dUTP nick-end labeling-positive neutrophils were increased at 12 h and onwards. Lavage levels of neutrophils and lactate dehydrogenase increased significantly at 4 and 24 h, respectively. Detailed electron microscopic assessment of neutrophil activation and death modes revealed that up to 14% of the neutrophils were undergoing secondary necrosis, whereas apoptotic or primary necrotic structural cells were rarely found. In summary, this study provides direct evidence that secondary necrosis of neutrophils is a common process during intense lung inflammation. This implies that neutrophil apoptosis may cause rather than resolve airway inflammation.
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| 16. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Extracellular matrix alterations and acute inflammation; developing in parallel during early induction of pulmonary fibrosis.
- 2012
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In: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 92:6, s. 917-925
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Journal article (peer-reviewed)abstract
- Pulmonary fibrosis is a hallmark of several systemic diseases such as systemic sclerosis. Initiation and early development is not well characterized, as initiation usually is unnoticed in patients, yet fibrosis has been considered a late event, occurring after an inflammatory phase. By utilizing an animal model, the starting point can be defined and the initiation process and early development thoroughly investigated. To investigate these processes from a systemic perspective, we choose a systemic administration route, instead of the more commonly used local administration. The aim of this work was to study the initiation of pulmonary fibrosis in an animal model and to investigate early alterations in connective tissue, cell turnover and acute immune response in lung parenchyma. Animals were injected subcutaneously with bleomycin, three times a week (w) for 1-4w (controls received saline). Total collagen was histologically assessed by Picro Sirius Red and Masson's Trichrome, collagen production by antibodies directed against N-terminal of procollagens I and III, proliferation by labeling with proliferating cell nuclear antigen, apoptosis by TUNEL and innate immunity by detecting neutrophils and macrophages. Total collagen was significantly increased at 1, 2 and 4w compared with controls. Procollagen I, was increased at 1w and remained increased, whereas procollagen III-staining was increased at 2w, compared with controls. Myofibroblasts were increased at all times as were proliferation, whereas apoptosis was increased from 2w. Neutrophils peaked at 1w (2779±820 cells/mm(2)) and gradually decreased, whereas macrophages peaked at 2w (135±29 cells/mm(2)). Subcutaneously administered bleomycin induces rapid alterations in connective tissue and cell turnover, suggesting a plasticity of the connective tissue. A transient neutrophilia is detected and increased number of macrophages likely represents a clearance process of said neutrophils. The study suggests fibrosis initiation and acute inflammation to occur in parallel in this model.Laboratory Investigation advance online publication, 2 April 2012; doi:10.1038/labinvest.2012.57.
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| 17. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Induction of Vascular Remodeling in the Lung by Chronic House Dust Mite Exposure.
- 2008
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In: American Journal of Respiratory Cell and Molecular Biology. - 1535-4989. ; 39, s. 61-67
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Journal article (peer-reviewed)abstract
- Structural changes to the lung are known to be associated with chronic asthma. In addition to the well-described alterations to the airway wall, asthma is also associated with vascular modifications, although this aspect of remodeling is poorly understood. We therefore sought to evaluate the character and kinetics of vascular remodeling in response to chronic aeroallergen exposure. However, since many OVA-driven models used to investigate allergic airway disease do so in the absence of persistent airway inflammation, we chose instead to employ a protocol of chronic respiratory exposure to house dust mite extract (HDM), which has been shown to induce persistent airway inflammation consistent with that seen in human asthmatics. Mice were exposed to HDM intranasally for 7 or 20 consecutive weeks, and resolution of the inflammatory and remodeling response to allergen was investigated 4 weeks following the end of a 7-week exposure protocol. Measures of vascular remodeling, including total collagen deposition, procollagen I-production, endothelial and smooth muscle cell proliferation, smooth muscle area and presence of myofibroblasts were investigated histologically in lung vessels of different sizes and locations. We observed an increase in total collagen content which did not resolve upon cessation of allergen exposure. Other parameters were significantly increased following 7 and/or 20 weeks of allergen exposure, but returned to baseline following allergen withdrawal. We conclude that respiratory HDM exposure induces not only airway remodeling, but also pulmonary vascular remodeling, and in accordance with airway remodeling, some components of these structural changes may be irreversible.
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| 18. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Neutrophil cannibalism--a back up when the macrophage clearance system is insufficient.
- 2006
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In: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 7:143, s. 143-143
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Journal article (peer-reviewed)abstract
- Background: During a lipopolysaccharide-induced lung inflammation, a massive accumulation of neutrophils occurs, which is normally cleared by macrophage phagocytosis following neutrophil apoptosis. However, in cases of extensive apoptosis the normal clearance system may fail, resulting in extensive neutrophil secondary necrosis. The aim of this study was to explore the hypothesis that neutrophils, in areas of the lung with extensive cellular infiltration, contribute to clearance by phagocytosing apoptotic cells and/or cell debris derived from secondary necrosis. Methods: Intranasal lipopolysaccharide administration was used to induce lung inflammation in mice. The animals were sacrificed at seven time points following administration, bronchoalveolar lavage was performed and tissue samples obtained. Electron microscopy and histochemistry was used to assess neutrophil phagocytosis. Results: Electron microscopic studies revealed that phagocytosing neutrophils was common, at 24 h after LPS administration almost 50% of the total number of neutrophils contained phagosomes, and the engulfed material was mainly derived from other neutrophils. Histochemistry on bronchoalvolar lavage cells further showed phagocytosing neutrophils to be frequently occurring. Conclusion: Neutrophils are previously known to phagocytose invading pathogens and harmful particles. However, this study demonstrates that neutrophils are also able to engulf apoptotic neutrophils or cell debris resulting from secondary necrosis of neutrophils. Neutrophils may thereby contribute to clearance and resolution of inflammation, thus acting as a back up system in situations when the macrophage clearance system is insufficient and/or overwhelmed.
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| 19. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Remodeling of extra-bronchial lung vasculature following allergic airway inflammation.
- 2008
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In: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 9:18, FEb 8
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Journal article (peer-reviewed)abstract
- BACKGROUND: We previously observed that allergen-exposed mice exhibit remodeling of large bronchial-associated blood vessels. The aim of the study was to examine whether vascular remodeling occurs also in vessels where a spill-over effect of bronchial remodeling molecules is less likely. METHODS: We used an established mouse model of allergic airway inflammation, where an allergic airway inflammation is triggered by inhalations of OVA. Remodeling of bronchial un-associated vessels was determined histologically by staining for alpha-smooth muscle actin, procollagen I, Ki67 and von Willebrand-factor. Myofibroblasts were defined as and visualized by double staining for alpha-smooth muscle actin and procollagen I. For quantification the blood vessels were divided, based on length of basement membrane, into groups; small (
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| 20. |
- Rydell-Törmänen, Kristina
(author)
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Remodeling of the pulmonary circulation - a novel response to allergic airway inflammation
- 2008
-
Doctoral thesis (other academic/artistic)abstract
- Asthma is characterized, not only by inflammation but also by airway and vascular remodeling. Airway remodeling is established early in disease, structural alterations have been found in children, and is thought to contribute to asthma symptoms. Unfortunately, airway remodeling is considered difficult to reverse and it seldom resolves completely. Studies of vascular involvement in asthma have mainly focused on the tracheal and bronchial microcirculation, as these vessels are relatively easy to obtain. Some scattered studies have investigated bronchial and pulmonary arteries, using autopsy specimens. The overall aim of the project was to investigate vascular remodeling by utilizing two different animal models of allergic airway inflammation (where chicken egg albumin (OVA) or house dust mite (HDM) extract were used as allergens). More specifically the structural alterations of remodeling, the time frame of development and the resolution were investigated. The studies show that vascular remodeling is a feature of allergic airway inflammation, despite which allergen used to initialize the inflammatory response. Both the systemic tracheal microvessels as well as all parts of the pulmonary circulation undergo changes. The structural alterations of vascular remodeling induced by allergic airway inflammation, was similar to features as seen in airway remodeling. Vascular remodeling appears to be only partially reversible, as some structural alterations seem to remain even when the allergic inflammation is resolved. In summary this thesis describes the involvement of the vasculature in airway inflammation, characterizes vascular remodeling and shows that similar structural alterations are induced by two different allergens.
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| 21. |
- Rydell-Törmänen, Kristina, et al.
(author)
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Smooth muscle in tissue remodeling and hyper-reactivity: Airways and arteries.
- 2013
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In: Pulmonary Pharmacology & Therapeutics. - : Elsevier BV. - 1522-9629 .- 1094-5539. ; 26:1, s. 13-23
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Research review (peer-reviewed)abstract
- Smooth muscle comprises a key functional component of both the airways and their supporting vasculature. Dysfunction of smooth muscle contributes to and exacerbates a host of breathing-associated pathologies such as asthma, chronic obstructive pulmonary disease and pulmonary hypertension. These diseases may be marked by airway and/or vascular smooth muscle hypertrophy, proliferation and hyper-reactivity, and related conditions such as fibrosis and extracellular matrix remodeling. This review will focus on the contribution of airway or vascular smooth dysfunction to common airway diseases.
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| 22. |
- Rydell-Törmänen, Kristina, et al.
(author)
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The Applicability of Mouse Models to the Study of Human Disease
- 2019
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In: Methods in molecular biology (Clifton, N.J.). - New York, NY : Springer New York. - 1940-6029. ; 1940, s. 3-22
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Journal article (peer-reviewed)abstract
- The laboratory mouse Mus musculus has long been used as a model organism to test hypotheses and treatments related to understanding the mechanisms of disease in humans; however, for these experiments to be relevant, it is important to know the complex ways in which mice are similar to humans and, crucially, the ways in which they differ. In this chapter, an in-depth analysis of these similarities and differences is provided to allow researchers to use mouse models of human disease and primary cells derived from these animal models under the most appropriate and meaningful conditions.Although there are considerable differences between mice and humans, particularly regarding genetics, physiology, and immunology, a more thorough understanding of these differences and their effects on the function of the whole organism will provide deeper insights into relevant disease mechanisms and potential drug targets for further clinical investigation. Using specific examples of mouse models of human lung disease, i.e., asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis, this chapter explores the most salient features of mouse models of human disease and provides a full assessment of the advantages and limitations of these models, focusing on the relevance of disease induction and their ability to replicate critical features of human disease pathophysiology and response to treatment. The chapter concludes with a discussion on the future of using mice in medical research with regard to ethical and technological considerations.
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