| 1. |
- Andersson, Cecilia K, et al.
(author)
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Activated MCTC mast cells infiltrate diseased lung areas in cystic fibrosis and idiopathic pulmonary fibrosis
- 2011
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In: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 12:139
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Journal article (peer-reviewed)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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| 2. |
- Weitoft, Maria, et al.
(author)
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Controlled and uncontrolled asthma display distinct alveolar tissue matrix compositions
- 2014
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In: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921. ; 15
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Journal article (peer-reviewed)abstract
- Objective: Whether distal inflammation in asthmatics also leads to structural changes in the alveolar parenchyma remains poorly examined, especially in patients with uncontrolled asthma. We hypothesized that patients who do not respond to conventional inhaled corticosteroid therapy have a distinct tissue composition, not only in central, but also in distal lung. Methods: Bronchial and transbronchial biopsies from healthy controls, patients with controlled atopic and patients with uncontrolled atopic asthma were processed for immunohistochemical analysis of fibroblasts and extracellular matrix molecules: collagen, versican, biglycan, decorin, fibronectin, EDA-fibronectin, matrix metalloproteinase (MMP)-9 and tissue-inhibitor of matrix metalloproteinase (TIMP)-3. Results: In central airways we found increased percentage areas of versican and decorin in patients with uncontrolled asthma compared to both healthy controls and patients with controlled asthma. Percentage area of biglycan was significantly higher in both central airways and alveolar parenchyma of patients with uncontrolled compared to controlled asthma. Ratios of MMP-9/TIMP-3 were decreased in both uncontrolled and controlled asthma compared to healthy controls. In the alveolar parenchyma, patients with uncontrolled asthma had increased percentage areas of collagen, versican and decorin compared to patients with controlled asthma. Patients with uncontrolled asthma had significantly higher numbers of myofibroblasts in both central airways and alveolar parenchyma compared to patients with controlled asthma. Conclusions: Tissue composition differs, in both central and distal airways, between patients with uncontrolled and controlled asthma on equivalent doses of ICS. This altered structure and possible change in tissue elasticity may lead to abnormal mechanical properties, which could be a factor in the persistent symptoms for patients with uncontrolled asthma.
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| 3. |
- Andersson Sjöland, Annika, et al.
(author)
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Fibroblast phenotypes and their activity are changed in the wound healing process after lung transplantation.
- 2011
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In: The Journal of Heart and Lung Transplantation. - : Elsevier BV. - 1557-3117 .- 1053-2498. ; 30, s. 945-954
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Journal article (peer-reviewed)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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| 4. |
- Andersson Sjöland, Annika, et al.
(author)
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Fibrocytes and the tissue niche in lung repair
- 2011
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In: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 12
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Research review (peer-reviewed)abstract
- Human fibrocytes are bone marrow-derived mesenchymal progenitor cells that express a variety of markers related to leukocytes, hematopoietic stem cells and a diverse set of fibroblast phenotypes. Fibrocytes can be recruited from the circulation to the tissue where they further can differentiate and proliferate into various mesenchymal cell types depending on the tissue niche. This local tissue niche is important because it modulates the fibrocytes and coordinates their role in tissue behaviour and repair. However, plasticity of a niche may be co-opted in chronic airway diseases such as asthma, idiopathic pulmonary fibrosis and obliterative bronchiolitis. This review will therefore focus on a possible role of fibrocytes in pathological tissue repair processes in those diseases.
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| 5. |
- Andersson-Sjöland, Annika, et al.
(author)
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Fibrocytes are a potential source of lung fibroblasts in idiopathic pulmonary fibrosis.
- 2008
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In: International Journal of Biochemistry & Cell Biology. - : Elsevier BV. - 1878-5875 .- 1357-2725. ; 40, s. 2129-2140
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Journal article (peer-reviewed)abstract
- Idiopathic pulmonary fibrosis is characterized by the accumulation of fibroblasts/myofibroblasts and aberrant remodeling of the lung parenchyma. However, the sources of fibroblasts in IPF lungs are unclear. Fibrocytes are circulating progenitors of fibroblasts implicated in wound healing and fibrosis. In this study we evaluated evidence for the presence of fibrocytes in the lung of patients with idiopathic pulmonary fibrosis by immunofluorescence and confocal microscopy. Fibrocytes were identified in tissues in 8 out of 9 fibrotic lungs. Combinations including CXCR4 and a mesenchymal marker stained significantly more fibrocytes/mm(2) of tissue compared with combinations using CD34 or CD45RO with mesenchymal markers: CXCR4/procollagen-I (10.3+/-2.9fibrocytes/mm(2)) and CXCR4/prolyl-4-hydroxylase (4.1+/-3.1), versus CD34/procollagen-I (2.8+/-3.0), CD34/alphaSMA (2.2+/-1.6) and CD45RO/prolyl-4-hydroxylase (1.3+/-1.6); p<0.003. There was a positive correlation between the abundance of fibroblastic foci and the amount of lung fibrocytes (r=0.79; p<0.02). No fibrocytes were identified in normal lungs. The fibrocyte attractant chemokine CXCL12 increased in plasma [median: 2707.5pg/ml (648.1-4884.7) versus 1751.5pg/ml (192.9-2686.0) from healthy controls; p<0.003)] and was detectable in the bronchoalveolar lavage fluid of 40% of the patients but not in controls. In the lung CXCL12 was strongly expressed by alveolar epithelial cells. A negative correlation between plasma levels of CXCL12 with lung diffusing capacity for carbon monoxide (DLCO) (r=-0.56; p<0.03) and oxygen saturation on exercise was found (r=-0.41; p<0.04). These findings indicate that circulating fibrocytes, likely recruited through the CXCR4/CXCL12 axis, may contribute to the expansion of the fibroblast/myofibroblast population in idiopathic pulmonary fibrosis.
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| 6. |
- Andersson Sjöland, Annika, et al.
(author)
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Fibrocytes are associated with vascular and parenchymal remodelling in patients with obliterative bronchiolitis.
- 2009
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In: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 10:Oct 30
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Journal article (peer-reviewed)abstract
- BACKGROUND: The aim of the present study was to explore the occurrence of fibrocytes in tissue and to investigate whether the appearance of fibrocytes may be linked to structural changes of the parenchyme and vasculature in the lungs of patients with obliterative bronchiolitis (OB) following lung or bone marrow transplantation. METHODS: Identification of parenchyme, vasculature, and fibrocytes was done by histological methods in lung tissue from bone marrow or lung-transplanted patients with obliterative bronchiolitis, and from controls. RESULTS: The transplanted patients had significantly higher amounts of tissue in the alveolar parenchyme (46.5 +/- 17.6%) than the controls (21.7 +/- 7.6%) (p < 0.05). The patients also had significantly increased numbers of fibrocytes identified by CXCR4/prolyl4-hydroxylase, CD45R0/prolyl4-hydroxylase, and CD34/prolyl4-hydroxylase compared to the controls (p < 0.01). There was a correlation between the number of fibrocytes and the area of alveolar parenchyma; CXCR4/prolyl 4-hydroxylase (p < 0.01), CD45R0/prolyl 4-hydroxylase (p < 0.05) and CD34/prolyl 4-hydroxylase (p < 0.05). In the pulmonary vessels, there was an increase in the endothelial layer in patients (0.31 +/- 0.13%) relative to the controls (0.037 +/- 0.02%) (p < 0.01). There was a significant correlation between the number of fibrocytes and the total area of the endothelial layer CXCR4/prolyl 4-hydroxylase (p < 0.001), CD45R0/prolyl 4-hydroxylase (p < 0.001) and CD34/prolyl 4-hydroxylase (p < 0.01). The percent areas of the lumen of the vessels were significant (p < 0.001) enlarged in the patient with OB compared to the controls. There was also a correlation between total area of the lumen and number of fibrocytes, CXCR4/prolyl 4-hydroxylase (p < 0.01), CD45R0/prolyl 4-hydroxylase (p < 0.001) and CD34/prolyl 4-hydroxylase (p < 0.01). CONCLUSION: Our results indicate that fibrocytes are associated with pathological remodelling processes in patients with OB and that tissue fibrocytes might be a useful biomarker in these processes.
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| 7. |
- 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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| 8. |
- Andersson Sjöland, Annika
(author)
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Tissue repair in lung disorders
- 2009
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Doctoral thesis (other academic/artistic)abstract
- The remodeling phase of tissue repair in lung disorders such as idiopathic pulmonary disease, asthma, obliterative bronchiolitis, and after lung transplantation is not well understood. One of the key players in fibrosis is the fibroblast and its progenitor, the fibrocyte. The fibroblast is the main producer of extracellular matrix molecules such as collagen, versican, perlecan, biglycan, and decorin. Fibrocytes are recruited from the bone marrow to the site of injury. It is possible that the stromal cell-derived factor-1/CXCL12 builds up in a gradient to recruit CXCR4 expressing fibrocytes, at least in the case of idiopathic pulmonary fibrosis. Patients with obliterative bronchilitis have an enlarged vessel lumen and a larger endothelial layer area, which has been shown to be correlated to more fibrocytes in the tissue. A correlation was found between the numbers of fibrocytes identified in tissue and structural changes in the lung. In idiopathic pulmonary fibrosis, a correlation was found between numbers of fibrocytes and numbers of fibroblastic foci, and in patients with obliterative bronchiolitis there was a correlation between fibrocyte numbers and thickening of the alveolar parenchyma. Eventually the fibrocyte enters the tissue and can differentiate into a fibroblast. Matrix production by fibroblasts in patients who have undergone lung transplantation and in asthmatic subjects involves both the central and the distal parts of the lung. In lung-transplanted patients, the production of proteoglycans in the distal part was found to be double that in the central part. Versican production was particularly elevated compared to controls. The production of proteoglycans was further correlated with proliferation rate. A common feature of fibroblasts in patients after lung transplantation and asthmatic subjects was that these cells proliferated more slowly than in control subjects. Distally-derived fibroblasts from asthmatic subjects produced more veriscan, were immobile, and had many protrusions. The distal parts of the lungs were also rich in collagen. A better understanding of fibrocyte and fibroblast function will help us to characterise the mechanisms behind idiopathic pulmonary disease, asthma, obliterative bronchiolitis. This knowledge can then be applied to other types of fibrotic disorders.
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| 9. |
- 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
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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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| 10. |
- Blank Savukinas, Ulrika, et al.
(author)
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The Bystander Effect : Mesenchymal Stem Cell-Mediated Lung Repair
- 2016
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In: Stem Cells. - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 34:6, s. 1437-1444
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Research review (peer-reviewed)abstract
- Mesenchymal stem or stromal cells (MSCs), a heterogeneous subset of adult stem/progenitor cells, have surfaced as potential therapeutic units with significant clinical benefit for a wide spectrum of disease conditions, including those affecting the lung. Although MSCs carry both self-renewal and multilineage differentiation abilities, current dogma holds that MSCs mainly contribute to tissue regeneration and repair by modulating the host tissue via secreted cues. Thus, the therapeutic benefit of MSCs is thought to derive from so called bystander effects. The regenerative mechanisms employed by MSCs in the lung include modulation of the immune system as well as promotion of epithelial and endothelial repair. Apart from secreted factors, a number of recent findings suggest that MSCs engage in mitochondrial transfer and shedding of membrane vesicles as a means to enhance tissue repair following injury. Furthermore, it is becoming increasingly clear that MSCs are an integral component of epithelial lung stem cell niches. As such, MSCs play an important role in coupling information from the environment to stem and progenitor populations, such that homeostasis can be ensured even in the face of injury. It is the aim of this review to outline the major mechanisms by which MSCs contribute to lung regeneration, synthesizing recent preclinical findings with data from clinical trials and potential for future therapy
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