Background And Purpose: Idiopathic pulmonary fibrosis (IPF) is a fatal respiratory disease characterized by excessive fibroblast activation ultimately leading to scarring of the lungs. Although, the activation of β -adrenoceptors (β -AR) has been shown to inhibit pro-fibrotic events primarily in cell lines, the role of β -adrenoceptor agonists has not yet been fully characterized. The aim of our study was to explore the anti-fibrotic activity of the long-acting β -adrenoceptor agonist olodaterol in primary human lung fibroblasts (HLF) and in murine models of pulmonary fibrosis.
View Article and Find Full Text PDFBI 1002494 [(R)-4-{(R)-1-[7-(3,4,5-trimethoxy-phenyl)-[1,6]napthyridin-5-yloxy]-ethyl}pyrrolidin-2-one] is a novel, potent, and selective spleen tyrosine kinase (SYK) inhibitor with sustained plasma exposure after oral administration in rats, which qualifies this molecule as a good in vitro and in vivo tool compound. BI 1002494 exhibits higher potency in inhibiting high-affinity IgE receptor-mediated mast cell and basophil degranulation (IC50 = 115 nM) compared with B-cell receptor-mediated activation of B cells (IC50 = 810 nM). This may be explained by lower kinase potency when the physiologic ligand B-cell linker was used, suggesting that SYK inhibitors may exhibit differential potency depending on the cell type and the respective signal transduction ligand.
View Article and Find Full Text PDFBackground And Purpose: β2 -adrenoceptor agonists are widely used in the management of obstructive airway diseases. Besides their bronchodilatory effect, several studies suggest inhibitory effects on various aspects of inflammation. The aim of our study was to determine the efficacy of the long-acting β2 -adrenoceptor agonist olodaterol to inhibit pulmonary inflammation and to elucidate mechanism(s) underlying its anti-inflammatory actions.
View Article and Find Full Text PDFExcessive coughing is a common feature of airway diseases. Different G-protein coupled receptors, including β2-adrenergic receptors (β2-AR), have been implicated in the molecular mechanisms underlying the cough reflex. However, the potential antitussive property of β2-AR agonists in patients with respiratory disease is a matter of ongoing debate.
View Article and Find Full Text PDFIdiopathic pulmonary fibrosis (IPF) is a progressive and ultimately fatal disease characterised by fibrosis of the lung parenchyma and loss of lung function. Although the pathogenic pathways involved in IPF have not been fully elucidated, IPF is believed to be caused by repetitive alveolar epithelial cell injury and dysregulated repair, in which there is uncontrolled proliferation of lung fibroblasts and differentiation of fibroblasts into myofibroblasts, which excessively deposit extracellular matrix (ECM) proteins in the interstitial space. A number of profibrotic mediators including platelet-derived growth factor (PDGF), fibroblast growth factor (FGF) and transforming growth factor-β are believed to play important roles in the pathogenesis of IPF.
View Article and Find Full Text PDFMast cells are central effector cells in allergic asthma and are augmented in the airways of asthma patients. Attenuating mast cell degranulation and with it the early asthmatic response is an important intervention point to inhibit bronchoconstriction, plasma exudation and tissue oedema formation. To validate the efficacy of novel pharmacological interventions, appropriate and practicable in vivo models reflecting mast cell-dependent mechanisms in the lung, are missing.
View Article and Find Full Text PDFAntagonizing the human M3 muscarinic receptor (hM3R) over a long time is a key feature of modern bronchodilating COPD drugs aiming at symptom relief. The long duration of action of the antimuscarinic drug tiotropium and its kinetic subtype selectivity over hM2R are investigated by kinetic mapping of the binding site and the exit channel of hM3R. Hence, dissociation experiments have been performed with a set of molecular matched pairs of tiotropium on a large variety of mutated variants of hM3R.
View Article and Find Full Text PDFComplement is an ancient danger-sensing system that contributes to host defense, immune surveillance and homeostasis. C5a and its G protein–coupled receptor mediate many of the proinflammatory properties of complement. Despite the key role of C5a in allergic asthma, autoimmune arthritis, sepsis and cancer, knowledge about its regulation is limited.
View Article and Find Full Text PDFThe spleen tyrosine kinase (Syk) is a key mediator of immunoreceptor signaling in immune cells. Thus, interfering with the function of Syk by genetic deletion or pharmacological inhibition might influence a variety of allergic and autoimmune processes. Since conventional Syk knockout mice are not viable, studies addressing the effect of Syk deletion in adult animals have been limited.
View Article and Find Full Text PDFSpleen tyrosine kinase (Syk) is a key regulatory factor in the IgE-mediated allergic signal transduction pathway in mast cells and basophils. Syk is phosphorylated on a number of tyrosines following the binding of IgE/allergen complexes to FcɛRI receptors leading to initiation of inflammatory signaling via downstream enzymes and scaffolding proteins. We examined the kinases responsible for the phosphorylation of key Syk tyrosines in rat RBL-2H3 basophilic cells and bone marrow-derived mast cells (BMMCs).
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