Application-specific approaches to MicroCT for evaluation of mouse models of pulmonary disease.

The advent of micro-computed tomography (microCT) has provided significant advancement in our ability to generate clinically relevant assessments of lung health and disease in small animal models. As microCT use to generate outcomes analysis in pulmonary preclinical models has increased there have been substantial improvements in image quality and resolution, and data analysis software. However, there are limited published methods for standardized imaging and automated analysis available for investigators.

Differences in respiratory oscillometry measurements using mouthpiece, mouth, and nasal mask in healthy adults.

Airway resistance measurements using oscillometry provide a potential alternative to spirometry in assessing airway obstruction and dynamics due to measurements taken during tidal breathing. Oscillometry typically requires participants to form a tight seal around a mouthpiece that can prove challenging for some people. To address this challenge, we conducted a prospective study to evaluate the effect of different interfaces like mouthpiece, mouth mask, and nasal mask on respiratory impedance results from oscillometry in a cohort of healthy adults.

Glutathione-S-transferase P promotes glycolysis in asthma in association with oxidation of pyruvate kinase M2.

Background: Interleukin-1-dependent increases in glycolysis promote allergic airways disease in mice and disruption of pyruvate kinase M2 (PKM2) activity is critical herein. Glutathione-S-transferase P (GSTP) has been implicated in asthma pathogenesis and regulates the oxidation state of proteins via S-glutathionylation. We addressed whether GSTP-dependent S-glutathionylation promotes allergic airways disease by promoting glycolytic reprogramming and whether it involves the disruption of PKM2.

Downregulation of DUOX1 function contributes to aging-related impairment of innate airway injury responses and accelerated senile emphysema.

Aging is associated with a gradual loss of lung function due to increased cellular senescence, decreased regenerative capacity, and impaired innate host defense. One important aspect of innate airway epithelial host defense to nonmicrobial triggers is the secretion of alarmins such as IL-33 and activation of type 2 inflammation, which were previously found to depend on activation of the NADPH oxidase (NOX) homolog DUOX1, and redox-dependent signaling pathways that promote alarmin secretion. Here, we demonstrate that normal aging of C57BL/6J mice resulted in markedly decreased lung innate epithelial type 2 responses to exogenous triggers such as the airborne allergen , which was associated with marked downregulation of DUOX1, as well as DUOX1-mediated redox-dependent signaling.

Oscillometry of the respiratory system: a translational opportunity not to be missed.

Airway oscillometry has become the de facto standard for quality assessment of lung physiology in laboratory animals and has demonstrated its usefulness in understanding diseases of small airways. Nowadays, it is seeing extensive use in daily clinical practice and research; however, a question that remains unanswered is how well physiological findings in animals and humans correlate? Methodological and device differences are obvious between animal and human studies. However, all devices deliver an oscillated airflow test signal and output respiratory impedance.

Comparing lung oscillometry with a novel, portable flow interrupter device to measure lung mechanics.

In the community setting, assessing spirometry in school-aged children is often limited by the unavailability of respirology technicians at the point-of-care. We developed a new technique called the Rapid Expiratory Occlusion Method (REOM) that measures respiratory resistance during normal breathing, without specialized training. The aim was to examine the concordance between respiratory resistance measured with the REOM and respiratory resistance measured by oscillometry on the tremoflo.

Back to the future: re-establishing guinea pig in vivo asthma models.

Research using animal models of asthma is currently dominated by mouse models. This has been driven by the comprehensive knowledge on inflammatory and immune reactions in mice, as well as tools to produce genetically modified mice. Many of the identified therapeutic targets influencing airway hyper-responsiveness and inflammation in mouse models, have however been disappointing when tested clinically in asthma.

Airway epithelial specific deletion of Jun-N-terminal kinase 1 attenuates pulmonary fibrosis in two independent mouse models.

The stress-induced kinase, c-Jun-N-terminal kinase 1 (JNK1) has previously been implicated in the pathogenesis of lung fibrosis. However, the exact cell type(s) wherein JNK1 exerts its pro-fibrotic role(s) remained enigmatic. Herein we demonstrate prominent activation of JNK in bronchial epithelia using the mouse models of bleomycin- or AdTGFβ1-induced fibrosis.

Oscillometry in Chronic Obstructive Lung Disease: In vitro and in vivo evaluation of the impulse oscillometry and tremoflo devices.

Impedance, or oscillometry, measurements of the respiratory system can generate information about the function of the respiratory system not possible with traditional spirometry. There are currently several instruments on the market using different perturbations. We have compared a new respiratory oscillometry instrument, the tremoflo, with Impulse Oscillometry (IOS).

Breath metabolome of mice infected with Pseudomonas aeruginosa.

Introduction: The measurement of specific volatile organic compounds in breath has been proposed as a potential diagnostic for a variety of diseases. The most well-studied bacterial lung infection in the breath field is that caused by Pseudomonas aeruginosa.

Objectives: To determine a discriminatory core of molecules in the "breath-print" of mice during a lung infection with four strains of P.

Towards the use of breath for detecting mycobacterial infection: a case study in a murine model.

In the present research, the potential of breath analysis by comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS) was investigated for the discrimination between healthy and infected mice. A pilot study employing a total of 16 animals was used to develop a method for breath analysis in a murine model for studying Mycobacterium tuberculosis complex (MTBC) using the M. bovis bacillus Calmette-Guérin.

IL-1/inhibitory κB kinase ε-induced glycolysis augment epithelial effector function and promote allergic airways disease.

Background: Emerging studies suggest that enhanced glycolysis accompanies inflammatory responses. Virtually nothing is known about the relevance of glycolysis in patients with allergic asthma.

Objectives: We sought to determine whether glycolysis is altered in patients with allergic asthma and to address its importance in the pathogenesis of allergic asthma.

Frequencies of micronucleated reticulocytes, a dosimeter of DNA double-strand breaks, in infants receiving computed tomography or cardiac catheterization.

The use of computed tomography (CT scans) has increased dramatically in recent decades, raising questions about the long-term safety of CT-emitted x-rays especially in infants who are more sensitive to radiation-induced effects. Cancer risk estimates for CT scans typically are extrapolated from models; therefore, new approaches measuring actual DNA damage are needed for improved estimations. Hence, changes in a dosimeter of DNA double-strand breaks, micronucleated reticulocytes (MN-RETs) measured by flow cytometry, were investigated in mice and infants exposed to CT scans.

The role of iNKT cells on the phenotypes of allergic airways in a mouse model.

iNKT cells and mast cells have both been implicated in the syndrome of allergic asthma through their activation-induced release of Th2 type cytokines and secretion of histamine and other mediators, respectively, which can promote airways hyperresponsiveness (AHR) to agents such as methacholine. However, a mechanistic link between iNKT cells and mast cell recruitment or activation has never been explored. Our objective was to determine whether iNKT cells are necessary for the recruitment of mast cells and if iNKT cells can influence the acute allergen induced bronchoconstriction (AIB) caused by mast cell mediator release.

DUOX1 mediates persistent epithelial EGFR activation, mucous cell metaplasia, and airway remodeling during allergic asthma.

Chronic inflammation with mucous metaplasia and airway remodeling are hallmarks of allergic asthma, and these outcomes have been associated with enhanced expression and activation of EGFR signaling. Here, we demonstrate enhanced expression of EGFR ligands such as amphiregulin as well as constitutive EGFR activation in cultured nasal epithelial cells from asthmatic subjects compared with nonasthmatic controls and in lung tissues of mice during house dust mite-induced (HDM-induced) allergic inflammation. EGFR activation was associated with cysteine oxidation within EGFR and the nonreceptor tyrosine kinase Src, and both amphiregulin production and oxidative EGFR activation were diminished by pharmacologic or genetic inhibition of the epithelial NADPH oxidase dual oxidase 1 (DUOX1).

Tumor necrosis factor alpha, citrullination, and peptidylarginine deiminase 4 in lung and joint inflammation.

Background: The relationship between lung and joint inflammation in rheumatoid arthritis is poorly understood. Lung inflammation with resultant protein citrullination may trigger anti-citrullinated protein antibodies, inflammation, and arthritis. Alternatively, lung and joint inflammation may be two manifestations of a single underlying pathology.

Ablation of Glutaredoxin-1 Modulates House Dust Mite-Induced Allergic Airways Disease in Mice.

Protein S-glutathionylation (PSSG) is an oxidant-induced post-translational modification of protein cysteines that impacts structure and function. The oxidoreductase glutaredoxin-1 (Glrx1) under physiological conditions catalyzes deglutathionylation and restores the protein thiol group. The involvement of Glrx1/PSSG in allergic inflammation induced by asthma-relevant allergens remains unknown.

Ablation of the Thiol Transferase Glutaredoxin-1 Augments Protein S-Glutathionylation and Modulates Type 2 Inflammatory Responses and IL-17 in a House Dust Mite Model of Allergic Airway Disease in Mice.

S-glutathionylation has emerged as an oxidant-induced post-translational modification of protein cysteines that affects structure and function. The oxidoreductase glutaredoxin-1 (Glrx1), under physiological conditions, catalyzes deglutathionylation and restores the protein thiol group. The involvement of Grx1/S-glutathionylation in allergic inflammation induced by asthma-relevant allergens remains unknown.

Dissecting the inflammatory twitch in allergically inflamed mice.

We have previously advanced the hypothesis that the allergic inflammatory response in the lungs occurs as a self-limited sequence of events that begins with the onset of inflammation and then resolves back to baseline over a predetermined time course (Pothen JJ, Poynter ME, Bates JH. J Immunol 190: 3510-3516, 2013). In the present study we tested a key prediction of this hypothesis, which is that the instigation of the allergic inflammatory response should be accompanied by a later refractory period during which the response cannot be reinitiated.

Mouse Invariant Monoclonal Antibody NKT14: A Novel Tool to Manipulate iNKT Cell Function In Vivo.

Invariant Natural Killer T (iNKT) cells are a T cell subset expressing an invariant T Cell Receptor (TCR) that recognizes glycolipid antigens rather than peptides. The cells have both innate-like rapid cytokine release, and adaptive-like thymic positive selection. iNKT cell activation has been implicated in the pathogenesis of allergic asthma and inflammatory diseases, while reduced iNKT cell activation promotes infectious disease, cancer and certain autoimmune diseases such as Type 1 diabetes (T1D).

Predicting the response of the injured lung to the mechanical breath profile.

Mechanical ventilation is a crucial component of the supportive care provided to patients with acute respiratory distress syndrome. Current practice stipulates the use of a low tidal volume (VT) of 6 ml/kg ideal body weight, the presumptive notion being that this limits overdistension of the tissues and thus reduces volutrauma. We have recently found, however, that airway pressure release ventilation (APRV) is efficacious at preventing ventilator-induced lung injury, yet APRV has a very different mechanical breath profile compared with conventional low-VT ventilation.

Anti-inflammatory effects of levalbuterol-induced 11β-hydroxysteroid dehydrogenase type 1 activity in airway epithelial cells.

Airway epithelial NF-κB activation is observed in asthmatic subjects and is a cause of airway inflammation in mouse models of allergic asthma. Combination therapy with inhaled short-acting β2-agonists and corticosteroids significantly improves lung function and reduces inflammation in asthmatic subjects. Corticosteroids operate through a number of mechanisms to potently inhibit NF-κB activity.

Absence of c-Jun NH2-terminal kinase 1 protects against house dust mite-induced pulmonary remodeling but not airway hyperresponsiveness and inflammation.

Chronic allergic asthma leads to airway remodeling and subepithelial fibrosis via mechanisms not fully understood. Airway remodeling is amplified by profibrotic mediators, such as transforming growth factor-β1 (TGF-β1), which plays a cardinal role in various models of fibrosis. We recently have identified a critical role for c-Jun-NH2-terminal-kinase (JNK) 1 in augmenting the profibrotic effects of TGF-β1, linked to epithelial-to-mesenchymal transition of airway epithelial cells.

Antigen-induced mast cell expansion and bronchoconstriction in a mouse model of asthma.

Lung mastocytosis and antigen-induced bronchoconstriction are common features in allergic asthmatics. It is therefore important that animal models of asthma show similar features of mast cell inflammation and reactivity to inhaled allergen. We hypothesized that house dust mite (HDM) would induce mastocytosis in the lung and that inhalation of HDM would trigger bronchoconstriction.