American journal of physiology. Lung cellular and molecular physiology
-
Am. J. Physiol. Lung Cell Mol. Physiol. · Aug 2015
Multidimensional immunolabeling and 4D time-lapse imaging of vital ex vivo lung tissue.
During the last decades, the study of cell behavior was largely accomplished in uncoated or extracellular matrix (ECM)-coated plastic dishes. To date, considerable cell biological efforts have tried to model in vitro the natural microenvironment found in vivo. For the lung, explants cultured ex vivo as lung tissue cultures (LTCs) provide a three-dimensional (3D) tissue model containing all cells in their natural microenvironment. ⋯ A novel protein transfer technology (FuseIt/Ibidi) shuttled fluorescently labeled α-smooth muscle actin antibodies into the native cells of living 3D-LTCs, enabling live monitoring of α-smooth muscle actin-positive stress fibers in native tissue myofibroblasts residing in fibrotic lesions of 3D-LTCs. Finally, this technique can be applied to healthy and diseased human lung tissue, as well as to adherent cells in conventional two-dimensional cell culture. This novel method will provide valuable new insights into the dynamics of ECM (patho)biology, studying in detail the interaction between ECM and cellular tissue components in their natural microenvironment.
-
Am. J. Physiol. Lung Cell Mol. Physiol. · Jul 2015
Comparative StudyCombination of erythromycin and dexamethasone improves corticosteroid sensitivity induced by CSE through inhibiting PI3K-δ/Akt pathway and increasing GR expression.
Corticosteroid insensitivity, which is induced by cigarette smoke extract (CSE), is a significant barrier when treating chronic obstructive pulmonary disease (COPD). Erythromycin (EM) has been shown to have an anti-inflammatory role in some chronic airway inflammatory diseases, particularly diffuse panbronchiolitis and cystic fibrosis. Here, we explored whether the combination therapy of EM and dexamethasone (Dex) reverses corticosteroid insensitivity and investigated the molecular mechanism by which this occurs. ⋯ Total Akt levels were unaffected by CSE or EM treatments. Furthermore, the combination treatment enhanced glucocorticoid receptor (GR)α expression. Our results demonstrate that the combination therapy of EM and Dex can restore corticosteroid sensitivity through inhibition of the PI3K-δ/Akt pathway and enhancing GRα expression.
-
Am. J. Physiol. Lung Cell Mol. Physiol. · Jul 2015
Il-17A contributes to maintenance of pulmonary homeostasis in a murine model of cigarette smoke-induced emphysema.
Smoking is the main risk factor for the development of the chronic obstructive pulmonary disease (COPD) in Western countries. Recent studies suggest that IL-17A and Th17 cells play a role in the pathogenesis of COPD. We used a murine model of chronic cigarette smoke (CS) exposure to explore the contribution of IL-17A to CS-induced lung damage and loss of pulmonary function. ⋯ Morphometry revealed destruction of lung tissue in CS-exposed IL-17A(-/-) mice similar to WT mice. The expression of elastin was decreased in air-exposed IL-17A(-/-) mice and in CS-exposed WT and IL-17A(-/-) mice. Thus, in the present model of sterile CS-exposure, IL-17A contributes to normal lung homeostasis and does not mediate CS-induced loss of lung structure and pulmonary function.
-
Am. J. Physiol. Lung Cell Mol. Physiol. · Jun 2015
Sphingosine-1-phosphate receptor 1 agonism attenuates lung ischemia-reperfusion injury.
Outcomes for lung transplantation are the worst of any solid organ, and ischemia-reperfusion injury (IRI) limits both short- and long-term outcomes. Presently no therapeutic agents are available to prevent IRI. Sphingosine 1-phosphate (S1P) modulates immune function through binding to a set of G protein-coupled receptors (S1PR1-5). ⋯ VPC01091 did not significantly affect elevated invariant natural killer T cell infiltration after IR, and administration of an S1PR1 antagonist reversed VPC01091-mediated protection after IR. In conclusion, VPC01091 and FTY720 provide comparable protection from lung injury and dysfunction after IR. These findings suggest that S1P-mediated protection from IRI is mediated by S1PR1 activation, independent of S1PR3, and that selective S1PR1 agonists may provide a novel therapeutic strategy to prevent lung IRI.
-
Am. J. Physiol. Lung Cell Mol. Physiol. · Jun 2015
STAT3-dependent CXC chemokine formation and neutrophil migration in streptococcal M1 protein-induced acute lung inflammation.
Streptococcus pyogenes cause infections ranging from mild pharyngitis to severe streptococcal toxic shock syndrome (STSS). The M1 serotype of Streptococcus pyogenes is most frequently associated with STSS. Herein, it was hypothesized that STAT3 signaling might be involved in M1 protein-evoked lung inflammation. ⋯ Interestingly, STAT3 inhibition markedly decreased plasma levels of IL-6 and HMGB1 in animals exposed to M1 protein. Moreover, we found that S3I-201 abolished CXCL2-induced neutrophil migration in vitro. In conclusion, these novel findings indicate that STAT3 signaling plays a key role in mediating CXC chemokine production and neutrophil infiltration in M1 protein-induced acute lung inflammation.