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Asthmatic Airways (asthmatic + airway)

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Medical Sciences100%

Terms modified by Asthmatic Airways

  • asthmatic airway inflammation
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    Selected Abstracts

    Blockade of CCR4 in a humanized model of asthma reveals a critical role for DC-derived CCL17 and CCL22 in attracting Th2 cells and inducing airway inflammation

    ALLERGY, Issue 7 2009
    F. Perros
    Background:, As Th2 type lymphocytes orchestrate the cardinal features of allergic asthma, inhibiting their recruitment to the lungs could be of therapeutic benefit. Although human Th2 cells express the CCR4 chemokine receptor and increased production of CCR4 ligands has been found in asthmatic airways, studies in animals have reached contradictory conclusions on whether blocking this pathway would be beneficial. Objective:, As a lack of efficacy might be due to differences between mouse and man, we readdressed this question using a humanized severe combined immunodeficiency model of asthma. Methods:, Mice received peripheral blood mononuclear cells from house dust mite (HDM) allergic asthmatic patients and then underwent bronchial challenge with HDM. Results:, This resulted in marked allergic inflammation and bronchial hyper-reactivity. Administration of CCR4 blocking antibody abolished the airway eosinophilia, goblet cell hyperplasia, IgE synthesis and bronchial hyperreactivity. In this chimeric system, human CD11c+ dendritic cells (DCs) were the predominant source of CCR4 ligands, suggesting that DC-derived chemokines attract Th2 cells. In separate experiments using human DCs, in vitro exposure to HDM of DCs from HDM allergic patients but not healthy controls caused CCL17 and CCL22 release that resulted in chemoattraction of polarized human Th2 cells in a CCR4-dependent way. Conclusions:, Taken together, our data provide proof of concept that CCR4 blockade inhibits the salient features of asthma and justify further clinical development of CCR4 antagonists for this disease. [source]

    Induction of glucocorticoid receptor-, expression in epithelial cells of asthmatic airways by T-helper type 17 cytokines

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 9 2010
    A. Vazquez-Tello
    Summary Background Corticosteroid insensitivity in asthmatics is associated with an increased expression of glucocorticoid receptor-, (GR-,) in many cell types. T-helper type 17 (Th17) cytokine (IL-17A and F) expressions increase in mild and in difficult-to-treat asthma. We hypothesize that IL-17A and F cytokines alone or in combination, induce the expression of GR-, in bronchial epithelial cells. Objectives To confirm the expression of the GR-, and IL-17 cytokines in the airways of normal subjects and mild asthmatics and to examine the effect of cytokines IL-17A and F on the expression of GR-, in bronchial epithelial cells obtained from normal subjects and asthmatic patients. Methods The expression of IL-17A and F, GR-, and GR-, was analysed in bronchial biopsies from mild asthmatics and normal subjects by Q-RT-PCR. Immunohistochemistry for IL-17 and GR-, was performed in bronchial biopsies from normal and asthmatic subjects. The expression of IL-6 in response to IL-17A and F and dexamethasone was determined by Q-RT-PCR using primary airway epithelial cells from normal and asthmatic subjects. Results We detected significantly higher levels of IL-17A mRNA expression in the bronchial biopsies from mild asthmatics, compared with normal. GR-, expression was significantly lower in the biopsies from asthmatics compared with controls. The expression of IL-17F and GR-, in biopsies from asthmatics was not significantly different from that of controls. Using primary epithelial cells isolated from normal subjects and asthmatics, we found an increased expression of GR-, in response to IL-17A and F in the cells from asthmatics (P0.05). This effect was only partially significant in the normal cells. Dexamethasone significantly decreased the IL-17-induced IL-6 expression in cells from normal individuals but not in those from asthmatics (P0.05). Conclusion Evidence of an increased GR-, expression in epithelial cells following IL-17 stimulation suggests a possible role for Th17-associated cytokines in the mechanism of steroid hypo-responsiveness in asthmatic subjects. Cite this as: A. Vazquez-Tello, A. Semlali, J. Chakir, J. G. Martin, D. Y. Leung, D. H. Eidelman and Q. Hamid, Clinical & Experimental Allergy, 2010 (40) 1312,1322. [source]

    Plasminogen activator inhibitor-1 and asthma: role in the pathogenesis and molecular regulation

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 8 2009
    Z. Ma
    Summary Plasminogen activator inhibitor (PAI)-1 is a major inhibitor of the fibrinolytic system. PAI-1 levels are markedly increased in asthmatic airways, and mast cells (MCs), a pivotal cell type in the pathogenesis of asthma, are one of the main sources of PAI-1 production. Recent studies suggest that PAI-1 may promote the development of asthma by regulating airway remodelling, airway hyperresponsiveness (AHR), and allergic inflammation. The single guanosine nucleotide deletion/insertion polymorphism (4G/5G) at ,675 bp of the PAI-1 gene is the major genetic determinant of PAI-1 expression. Plasma PAI-1 level is higher in people with the 4G/4G genotype than in those with the 5G/5G genotype. A strong association between the 4G/5G polymorphism and the risk and the severity of asthma has been suggested. Levels of plasma IgE and PAI-1 and severity of AHR are greater in asthmatic patients with the 4G/4G genotype than in those with the 5G/5G genotype. The PAI-1 promoter with the 4G allele renders higher transcription activity than the PAI-1 promoter with the 5G allele in stimulated MCs. The molecular mechanism for the 4G allele-mediated higher PAI-1 expression is associated with greater binding of upstream stimulatory factor-1 to the E-box adjacent to the 4G site (E-4G) than to the E-5G. In summary, PAI-1 may play an important role in the pathogenesis of asthma. Further studies evaluating the mechanisms of PAI-1 action and regulation may lead to the development of a novel prognostic factor and therapeutic target for the treatment and prevention of asthma and other PAI-1-associated diseases. [source]

    Increases in collagen type I synthesis in asthma: the role of eosinophils and transforming growth factor-b,

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 6 2002
    A. Nomura
    Summary Background Collagen type I is one of the major deposits in thickening of the reticular basement membrane of asthma. Objective and Methods In this study, we assessed turnover of collagen type I in asthma by measuring procollagen type I C-terminal peptide (PICP) and collagen type I C-terminal telopeptide (ICTP) in induced sputum. Results PICP but not ICTP was found to be significantly higher in asthma subjects than in normal volunteers (P < 0.05). In asthma, PICP was inversely correlated with %FEV1.0 (r = ,0.539), and its levels significantly increased upon exacerbation (P < 0.05), indicating that collagen synthesis increases during asthma exacerbation. Additionally, PICP was found to significantly correlate with eosinophil counts in sputum (r = 0.539), indicating that eosinophils stimulate collagen turnover. Because eosinophils can produce TGF-,, a potent stimulator of collagen synthesis, we immunocytochemically examined TGF-,-positive cells in sputum. TGF-,-positive cells significantly correlated with eosinophil counts (r = 0.811) and PICP (r = 0.569), suggesting that TGF-, released from eosinophils is involved in collagen synthesis. Conclusions The results of the present study suggest that collagen synthesis is stimulated in asthmatic airways by eosinophils through TGF-,, while collagen degradation is not, and that PICP in sputum can act as a new marker for airway inflammation in asthma. [source]